Code SOS - your essential code blog

WCF Service failing with “The server has rejected the client credentials”.

2011-05-29T11:50:00.000+03:00

Great article regarding an issue that happens a lot

Step By Step Creating WPF User Control

2011-04-12T14:48:00.000+03:00

1. Create WPF User control library. It will create such class

partial class MySuperTextBox : UserControl

2. Create DependencyProperty via propdp

public int MyProperty

{

get { return (int)GetValue(MyPropertyProperty); }

set { SetValue(MyPropertyProperty, value); }

}

// Using a DependencyProperty as the backing store for MyProperty. This enables animation, styling, binding, etc...

public static readonly DependencyProperty MyPropertyProperty =

DependencyProperty.Register("MyProperty", typeof(int), typeof(ownerclass), new UIPropertyMetadata(0));

3. No you can change the dp to the type you need

public string Text

{

get { return (string)GetValue(TextProperty); }

set { SetValue(TextProperty, value); }

}

// Using a DependencyProperty as the backing store for Text. This enables animation, styling, binding, etc...

public static readonly DependencyProperty TextProperty =

DependencyProperty.Register("Text", typeof(string), typeof(MySuperTextBox), new FrameworkPropertyMetadata("red", new PropertyChangedCallback(qwe)));

4. The difference between UIPropertyMetadata to FrameworkPropertyMetadata is that UIPropertyMetadata does only initialize the dp , FrameworkPropertyMetadata can also fire events.

5. new FrameworkPropertyMetadata("red", new PropertyChangedCallback(qwe)));

qwe is a function with this signature (need to do that manually).

private static void qwe(DependencyObject obj,DependencyPropertyChangedEventArgs args)

{

MySuperTextBox mstb = obj as MySuperTextBox;

mstb.txt.Text = args.NewValue.ToString();

}

6. That closed the User Control.

7. If you want to use this control in a WPF application.

8. Create WPF application

9. You can see the user control in the toolbox

10. Drag it to your XAML

11. This will

a. Add reference

b. Add xmlns : xmlns:my="clr-namespace:MyControl;assembly=MyControl">

c. Add the control to the XAML <my:MySuperTextBox Name="mySuperTextBox2" />

d. You can bind the dp in the user control to other data (textBox1 is a TextBox Control):

<my:MySuperTextBox Name="mySuperTextBox1" Text="{Binding ElementName=textBox1, Path=Text}" />

12. That’s it.

changing VC++ include setting for all projects in 1 solution

2011-03-09T11:37:00.000+02:00

Here are the steps to change the settings file through UI:

Open up property manager by clicking on View.Property Manager.

Expand the project node and then the Configuration|Platform nodes, you will see "Microsoft.cpp..users" file for each Configuration|Platform. These are the files for the global settings, similar to the old tools/Options/VC++ Directories.

Multi-Select "Microsoft.cpp..users", right click and bring up the property page window

In the property page window, click on "VC++ Directories" (for example) in the left pane, add new paths for the directories such as "Include Directories". separated by semicolons

Make sure to save the settings before shutting down Visual Studio.

Re-launch Visual Studio and the new settings will be in effect.

If you would like to only change the settings for a specific project, you can right click on the project and bring up the property page. Change the settings for “VC++ Directories”, these settings will be persisted to the project file.

WCF Contract - Overloading Methods

2011-02-20T10:41:00.001+02:00

If you need to overload a funtion in WCF contract , you've probably encountered in :

Cannot have two operations in the same contract with the same name, methods ***** and ****** in type ******* violate this rule. You can change the name of one of the operations by changing the method name or by using the Name property of OperationContractAttribute

Here's how to fix this issue (second option)

http://www.switchonthecode.com/snippet-tutorials/wcf-snippet-tutorial-overloading-methods

2 Endpoints for netTcpBinding with different contracts

2011-02-13T10:47:00.003+02:00

Need to use same netTcpBinding binding but need additional endpoint for different contract? here's how:

1. It's very good to read this article
2. If you have current netTcpBinding it should look like this:

3. what you have here is a TCP type of WCF with base address. Thats a deafult implementation of netTcpBinding.
4. I suggest you to use the VS20010 tool "Edit WCF Configuration" to edit the App.config file instead of manually edition it.
5. Add additional end point same values as the 1'st netTcpBinding binding (leave the MexTcpBidingEndpoint alone)
6. Change the folowing :

give each endpoint a name (the default implementation keeps them empty , it's good to give them some name to know on which one you are working on
for each give a unique name in the address section , thats the magic here , giving the base address (see host baseaddress section) allownig wach binding to "sit" in a unique position within the service , leaving this section empty will cause assertion such as "When multiple endpoints on a service share the same ListenUri, those endpoints must all have the same Identity in their EndpointAddress."
For each binding state the contract.

7. the app.config script should look like this:

8. Thats it , Cool , no?

XSD to byte array and vice versa

2011-01-30T10:07:00.000+02:00

need to construct your own byte array from a defiined XSD ? heres how

first construct the class from XSD (or XML)

we use XSD tool

go to Visual studio command prompt
Go to path of xsd file(I.E c:\xsd)
xsd [file name].xsd /c /n:[namespace]
where

/c – generate classes
/n - namespace

Now you have created the class representation of the XML (or XSD) file.
you can now use this 2 functions to serialize and deserialize the objects , to byte array and from byte array

public static byte[] ObjectToXmlBytes(object o)

{

MemoryStream memoryStream = new MemoryStream();

XmlSerializer serializer = new XmlSerializer(o.GetType());

serializer.Serialize(memoryStream, o);

return memoryStream.ToArray();

}

public static object XmlBytesToObject(byte[] bytes, Type t)

{

MemoryStream memoryStream = new MemoryStream(bytes);

memoryStream.Position = 0;

XmlSerializer serializer = new XmlSerializer(t);

return serializer.Deserialize(memoryStream);

}

enjoy

MFC - Route Menu commands ElseWhere

2009-07-21T11:20:00.001+03:00

Want to Handle Menu command where ever you want? - Use this code


void CUtilities::CmdRouteMenu(CWnd* pWnd, CMenu* pPopupMenu)
{
 CCmdUI state;
 state.m_pMenu = pPopupMenu;
 state.m_pParentMenu = pPopupMenu;
 state.m_nIndexMax = pPopupMenu->GetMenuItemCount();


 for (state.m_nIndex = 0; 
      state.m_nIndex < state.m_nIndexMax; 
      state.m_nIndex++) 
 {
  state.m_nID = pPopupMenu->GetMenuItemID(state.m_nIndex);

  // menu separator or invalid cmd - ignore it
  if (state.m_nID == 0) continue; 

  if (state.m_nID == (UINT)-1)
  {
   // possibly a popup menu, route to child menu if so
   CMenu* pSub=pPopupMenu->GetSubMenu(state.m_nIndex);
   if(pSub) CmdRouteMenu(pWnd,pSub);
  }
  else 
  {
   // normal menu item, Auto disable if command is _not_ a system command.
   state.m_pSubMenu = NULL;
   state.DoUpdate(pWnd, FALSE);
  }
 }
}

Usage:

CMenu menu;
if  ( menu.LoadMenu(uMenuID) )
{
 CMenu * pMenu = (CMenu*)menu.GetSubMenu(0);
 CUtilities::CmdRouteMenu(&m_pParent, pMenu); // Make sure commands get to parent window
 // Route commands to parent window:
 POINT pt;
 GetCursorPos(&pt);
 pMenu->TrackPopupMenu(TPM_RIGHTBUTTON|TPM_LEFTALIGN, pt.x, pt.y, &m_pParent);
}

MFC - Find if a given string is numeric

2009-07-14T09:32:00.002+03:00

Find if a given string is numeric



bool IsNumeric(const CString& str, bool bIsInt)
{
 int nSize = str.GetLength();
 int ReturnValue = 0;
 int DotCounter = 0;
 bool bContiue = true;


 //-------Case of integer--------------------------
 if ( bIsInt )
 {
  // Goes over the string characters
  for ( int i=0; i < nSize; i++ )
  {
   ReturnValue = isdigit( str.GetAt(i) );
   if ( !ReturnValue )
   {
    CString strChar = str.GetAt(i);
    if ( (i == 0) && (strChar=="-") )
     bContiue = true;
    else
     bContiue = false;
   }

   if ( !bContiue )
    return false;
  }

  return true;
 }

 //-------Case of double----------------------
 // Goes over the string characters
 for ( int i=0; i < nSize; i++ )
 {
  ReturnValue = isdigit( str.GetAt(i) );
  if ( !ReturnValue )
  {
   CString strChar = str.GetAt(i);
   if ((i == 0) && (strChar=="-") )
    bContiue = true;
   else if ( (i!=0) && (strChar== ".") && (DotCounter==0) )
   {
    DotCounter = 1;
    bContiue = true;
   }
   else
    bContiue = false;
  }

  if ( !bContiue )
   return false;
 }

 return true;
}

MFC - Wait until a file or path does or not not exist

2009-07-14T09:25:00.002+03:00

useful code to wait till a file path does or not exists


BOOL FileExist( LPTSTR pszFilePath )
{
 BOOL bRetVal;

 if( _taccess( pszFilePath , 0 ) == 0 )
 {
  bRetVal = TRUE;
 }
 else
 {
  bRetVal = FALSE;
 }
 
 return bRetVal;
}


BOOL WaitForFileNotExist( LPTSTR pszPath , DWORD dwTimeout )
{
 int nCount = dwTimeout/100;
 int nCounter = 0;

 if( nCount < 1 )
 {
  // timeout must be more or equal to 1 !!
  return FALSE;
 }

 // only exit the loop when the file is present or timeout occurs
 while( !FileExist(pszPath) && nCounter  < nCount )
 {
  Sleep(100);
  nCounter++;
 }

 if( nCounter >= nCount )
 {
  return FALSE;
 }

 return TRUE;
}

BOOL WaitForFileExist( LPTSTR pszPath , DWORD dwTimeout )
{
 int nCount = dwTimeout/100;
 int nCounter = 0;

 if( nCount < 1 )
 {
  // timeout must be more or equal to 1 !!
  return FALSE;
 }

 // only exit the loop when the file is present or timeout occurs
 while( !FileExist(pszPath) && nCounter  < nCount )
 {
  ::Sleep(100);
  nCounter++;
 }

 if( nCounter >= nCount )
 {
  return FALSE;
 }

 return TRUE;
}

MFC - Delete Path Recursive

2009-07-14T09:22:00.003+03:00

Want to Delete entire path? Use this


void CMyFileManager::DeletePathRecursive( LPTSTR pszPathToDelete )
{
 CString  strCurPathToDelete;
 CString  strCurFileFound;
 CFileFind FileFinder;


 strCurPathToDelete.Format( _T("%s\\*.*") ,  pszPathToDelete );

 BOOL bWorking = FileFinder.FindFile( strCurPathToDelete );
 while ( bWorking )
 {
  bWorking = FileFinder.FindNextFile();
  
  if ( FileFinder.IsDots() ) continue;

  strCurFileFound = FileFinder.GetFilePath();
  
  if ( FileFinder.IsDirectory() )
  {
   // Found a sub-directory - delete it recursivly:
   DeletePathRecursive( strCurFileFound.GetBuffer(0) );
  
   // Delete the sub-directory itself:
   TRACE( _T("\nDeleting sub-directory %s") , strCurFileFound );
   RemoveDirectory( strCurFileFound.GetBuffer(0) );
  }
  else
  {
   // Found a file - delete it:
   TRACE( _T("\nDeleting file %s") , strCurFileFound );
   DeleteFile( strCurFileFound );
  }
 }
}

"funny" memory values

2009-06-18T11:58:00.001+03:00

Thanks to bimba.

0xcccccccc

When the code is compiled with the /GZ option, uninitialized variables are automatically assigned to this value (at byte level). - you define a variable - this is its default value

0xdddddddd
After you delete an object - Memory that has been released with delete or free. It is used to detect writing through dangling pointers.

0xcdcdcdcd
Allocated memory via malloc or new but never written by the application.

0xfdfdfdfd
Also known as "no mans land." This is used to wrap the allocated memory (like surrounding it with fences) and is used to detect indexing arrays out of bounds.

0xBAADFOOD(bad food)
Memory allocated by LocalAlloc() with LMEM_FIXED, but not yet written to.

0xabababab
Memory allocated by LocalAlloc()

Watch Window Tips for Visual Studio 2003

2009-06-18T11:10:00.005+03:00

Edit autoexp.dat Which is located in C:\Program Files\Microsoft Visual Studio .NET 2003\Common7\Packages\Debugger

Show Vecor Size
Add this line :


std::vector <*> = size = , capacity = 

List of additional Object that can be better "Watched" .

Call GetLastError in the Watch Tab in Debugger

2009-06-18T10:08:00.002+03:00

Want to see GetLastError messsage on run time?

just add “@err” or “@err,hr” to your debug watch window. Now it’s more like looking at errno.

move a dialog without a caption

2009-06-02T16:46:00.003+03:00

how can you move a dialog without a caption (title)?

Thanks to bimba.



simply add this code:

UINT CClientRectDlg:: OnNcHitTest(CPoint point) 
{ 
   UINT ret = CDialog:: OnNcHitTest(point); 
   if(ret == HTCLIENT) 
     return HTCAPTION; 
   else return ret; 
} 

you have to add this to the message_map ON_WM_NCHITTEST()

Nice ah?

Lingo - Translate hex to rgb format

2009-06-02T09:28:00.002+03:00

Ever wanted to transform Hex to RGB? Use this useful utility


on HexToRGB hex
  ---------------------------------------------------------------
  -- Name:HexToRGB
  -- Input:hex string
  -- Description:Translate hex to rgb format
  --
  --
  -- Output:rgb value
  ---------------------------------------------------------------
  
  num1=0
  num2=0
  num3=0

  
  str1=hex.char[2]&hex.char[1]
  str2=hex.char[4]&hex.char[3]
  str3=hex.char[6]&hex.char[5]
  
  repeat with i=1 to 2
    case (str1.char[i]) of
      "A":num1=num1+power(i,4)*10
      "B":num1=num1+power(i,4)*11
      "C":num1=num1+power(i,4)*12
      "D":num1=num1+power(i,4)*13
      "E":num1=num1+power(i,4)*14
      "F":num1=num1+power(i,4)*15
      otherwise:  num1=num1+power(i,4)*integer(str1.char[i])
    end case
    
  end repeat
  repeat with i=1 to 2
    case (str2.char[i]) of
      "A":num2=num2+power(i,4)*10
      "B":num2=num2+power(i,4)*11
      "C":num2=num2+power(i,4)*12
      "D":num2=num2+power(i,4)*13
      "E":num2=num2+power(i,4)*14
      "F":num2=num2+power(i,4)*15
      otherwise:  num=num+power(i,4)*integer(str2.char[i])
    end case
  end repeat
  repeat with i=1 to 2
    case (str3.char[i]) of
      "A":num3=num3+power(i,4)*10
      "B":num3=num3+power(i,4)*11
      "C":num3=num3+power(i,4)*12
      "D":num3=num3+power(i,4)*13
      "E":num3=num3+power(i,4)*14
      "F":num3=num3+power(i,4)*15
      otherwise:  num3=num3+power(i,4)*integer(str3.char[i])
    end case
    --i=i-1
  end repeat
  return (rgb(num1,num2,num3))
end

Lingo - "CString" like operation on strings

2009-05-27T08:40:00.003+03:00

Coding in Lingo? (Macromedia and shockwave) here are some useful string utilities to help you



on new me
  return me
end new

on trimLeadingWhiteSpace str
  FuncName="trimLeadingWhiteSpace"      
  ---------------------------------------------------------------
  -- Name:trimLeadingWhiteSpace
  -- Input:String
  -- delete whitespace on the beginning of the string
  --
  --
  -- Output:String
  ---------------------------------------------------------------
  
  theCount = str.char.count
  whiteSpace = " "
  repeat with i = 1 to theCount
    if whiteSpace contains str.char[i]then
      next repeat
    else
      outStr = str.char[i..theCount]
      exit repeat
    end if
  end repeat
  return outStr
end



On TrimLeft me,str,subStr
  FuncName="TrimLeft"  
  if(voidp(subStr)) then -- trim leading spaces
    retStr= word 1 to the number of words in str of str
  else
    offsetNum=length(subStr)
    retStr=chars (str, offsetNum+1, length(str))
  end if
  return retStr
end


on strReplace me,input, stringToFind, stringToInsert
  FuncName="strReplace"      
  -- search and replace char in a string
  output = ""
  findLen = stringToFind.length - 1
  repeat while input contains stringToFind
    currOffset = offset(stringToFind, input)
    output = output & input.char [1..currOffset]
    delete the last char of output
    output = output & stringToInsert
    delete input.char [1.. (currOffset + findLen)] 
  end repeat
  set output = output & input
  return output
end



on GetFileTitle me,str,pref
  offs=offset(pref,str)
  repeat with i=offs down to 1
    if(str.char[i..i]="\" or str.char[i..i]="/" ) then
      posOfSlesh=i
      i=1
    end if
  end repeat
  substring=chars (str, 0, posOfSlesh)
  ret=me.TrimLeft(str,substring)
  ret=me.TrimRight(ret,pref)
  return ret
end


on trimspaces me, t
  FuncName="trimspaces"      
  return word 1 to the number of words in t of t
end



on SetLocalPath me, str
  FuncName="SetLocalPath"      
  -- set the local path for local play
  retStr=me.strReplace(str,"file://","")
  if(retStr.char[1]="/") then
    retStr=chars (retStr, 2,length(retStr))
    retStr=me.strReplace(retStr,"/","\")
    retstr=me.strReplace(retstr,"|",":")
  else --local web path
    retStr=me.strReplace(retStr,"/","\")
    retstr=me.strReplace(retstr,"|",":")
    retstr="\\"&retstr
  end if
  return retStr
end


on GetContent me, _url,str
  FuncName="GetContent"      
  --Get the content of a known path (I.E. http://Test/league.htm -> http://Test/DswMedia)
  EndOffset=offset(str,_url)
  retStr=chars (_url, 0,EndOffset-1)
  retstr=retstr&"DswMedia"
  return retStr
end


on TrimRight me,_source,str  
  FuncName="TrimRight"      
  -- trim the right string from source
  offsetNum=length(str)
  retStr=chars (_source, 0, length(_source)-offsetNum)
  retStr=me.trimspaces(retStr)  
  return retStr
end TrimRight



on String2List me,str
  _list=[]
  repeat with i=1 to str.length
    if(str.char[i..i]<>",") then
      _list.append(str.char[i..i])
    end if
  end repeat
  return _list
end

C++ - Build Recrusive Folder presentation from current location

2009-05-26T09:45:00.006+03:00

This code demonstrates how to print out a recursive folder presentation from any where in the drive the output file "Tree.txt" contains the "level" number of folder in the hierarchy and it's name You can also contain the files in the folder by changing if( c_file.attrib&_A_SUBDIR && strchr(c_file.name,'.')==0) to if(strchr(c_file.name,'.')==0)


#include 
#include 
#include 
#include 

#define _MAX_PATH 255


int FindLevel(char *s)
{
 int result=0;
 for(int i=1;i {
  if(s[i]=='\\') result++;
 }
 return result;
}

void BuildTree(char *path,FILE *fp,int nTreeLevel)
{
 struct _finddata_t c_file;
    long hFile; 
 char tmp[_MAX_PATH];
 strcpy(tmp,path);
 strcat(tmp,"\\*.*\0");
 
 if( (hFile = _findfirst( tmp, &c_file )) == -1L )
       printf( "No *.* files in current directory!\n" );
    else
    {
            while( _findnext( hFile, &c_file ) == 0 )
            {
                if( c_file.attrib&_A_SUBDIR && strchr(c_file.name,'.')==0)
    {
     int NewLevel=0;
     strcpy(tmp,path);
     strcat(tmp,"\\");
     strcat(tmp,c_file.name);
     int i=FindLevel(path);
     if(i>nTreeLevel)  NewLevel=i-nTreeLevel;
     fprintf(fp,"%d %s\n",NewLevel,c_file.name); 
     BuildTree(tmp,fp,nTreeLevel);
    }
            }
    _findclose( hFile );
    }
    
}


int main(int argc, char* argv[])
{
 FILE *fp;
 char buffer[_MAX_PATH];
   /* Get the current working directory: */
   if( _getcwd( buffer, _MAX_PATH ) == NULL )
      perror( "_getcwd error" );
   else
   {
    if((fp=fopen("c:\\Tree.txt","w"))==NULL)
  {
   printf( "Error opening file" );
   return -1;
  }
  /* Find first *.* file in current directory */
  BuildTree(buffer,fp,FindLevel(buffer));
  fclose(fp);
   }
 return 0;
}

C++ - HowTo printf on release version

2009-05-26T08:59:00.001+03:00

Ever wanted to know where you are in your code when running a release version? use this

AllocConsole();
freopen("conin$", "r", stdin);
freopen("conout$", "w", stdout);
freopen("conout$", "w", stderr);

and now you can use "printf" to output debug on a simple console.

MFC - Vertical button with text

2009-05-14T09:04:00.003+03:00

Ever wanted to place a vertical button on your application? use this code



1. You will have to Subclass CButton
2. change the fon't lfEscapement ,lfOrientation  to 2700
        GetFont(&tLogFont);
 tLogFont.lfEscapement = tLogFont.lfOrientation = 2700;
 m_bRotation = bRotation;
 SetFont(&tLogFont);

3. overide the ::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct) 
   function

4. Draw the caption

 int nAlign = _pDC->SetTextAlign (TA_BASELINE);
 CRect rc;
 GetClientRect(rc);
 CPoint pt;
 CSize sSizeExt = _pDC->GetTextExtent(sCaption);
 GetViewportOrgEx (_pDC->m_hDC,&pt) ;
 SetViewportOrgEx (_pDC->m_hDC,rc.Width() / 2, 
                                      rc.Height() / 2, NULL) ;
 int nPosOfStart =(rc.Height()/2)+(rc.Height()-sSizeExt.cx)/2;
 if(sSizeExt.cx>rc.Height()) nPosOfStart = rc.Height()/2;
 int nPosX = min(0,(sSizeExt.cy-rc.Width())/2);
 _pDC->TextOut (nPosX, ((nState-1) *rc.Height()) + 
                                       nPosOfStart, sCaption) ;
 SetViewportOrgEx (_pDC->m_hDC,pt.x / 2, pt.y / 2, NULL) ;
 _pDC->SetTextAlign (nAlign);

C++ , MFC - get COLORREF value from string

2009-05-13T09:11:00.005+03:00

Ever wanted to get COLORREF value from string? use this


COLORREF CClassName::GetColorFromStr(char * str)
{
 int r = 255,g = 255,b = 255;
 if(str && strlen(str)>=5)  // minimum size
 {
  CString sStr(str);
  int curPos= 0;
  CString resToken= sStr.Tokenize(",",curPos);
  int nIndex=0;
  while (resToken != "")
  {
   if(nIndex == 0)
    r = atoi(resToken);
   else if (nIndex == 1)
    g = atoi(resToken);
   else
    b= atoi(resToken);
   nIndex++;
   resToken= sStr.Tokenize(",",curPos);
  };
 }
 return RGB(r,g,b);
}

C++ - How to convert between 'CString' and 'std::string'?

2009-05-13T09:02:00.002+03:00

Simple But Still Annoying

'CString' to 'std::string'

Code:


CString cs("Hello");
std::string s((LPCTSTR)cs);

'std::string' to 'CString':

Code:


std::string s("Hello");
CString cs(s.c_str());

QT - Resize QPushButton to fit it's text

2009-05-10T09:59:00.002+03:00

Maybe there are better ways but this is how i did it

1. subclass QPushButton.
2. overwrite the virtual sizeHint() function
3. In this function return the prefered sizeHint (QPushButton sizeHint().width=80)
4. call adjustSize() on your subclassed QPushButton.



Header

class QModifiedQPushButton : public QPushButton
{
    Q_OBJECT
public:
    QModifiedQPushButton(const QString &text ,QWidget * parent = 0, const char * name = 0 ); 
    virtual ~QModifiedQPushButton();
    QSize sizeHint() const;
};
 
CPP



QModifiedQPushButton::QModifiedQPushButton(const QString &text ,QWidget * parent,const char * name) : QPushButton(text,parent,name)
{
 
}
 
QModifiedQPushButton::~QModifiedQPushButton()
{
 
}
 
QSize QModifiedQPushButton::sizeHint() const
{
    return QSize(40,28); // you can return whatever size here
}

Singleton Design Pattern in c++

2009-05-09T08:35:00.004+03:00

if you want a class that has only one representation in the proccess

declaration

class Singleton
{
public: static Singleton* Instance();
protected: Singleton();
Singleton(const Singleton&);
Singleton& operator= (const Singleton&);
private:
static Singleton* pinstance;
};

implementation

Singleton* Singleton::pinstance = 0;// initialize pointer

Singleton* Singleton::Instance ()
{
if (pinstance == 0) // is it the first call?
{
pinstance = new Singleton; // create sole instance
}
return pinstance; // address of sole instance
}

Singleton::Singleton()
{ //... perform necessary instance initializations
}

usage

Singleton *p1 = Singleton::Instance();
Singleton *p2 = p1->Instance();
Singleton & ref = * Singleton::Instance();

C# - Why a mdi form does not produce a click event?

2009-05-07T09:00:00.002+03:00

It doesn't fire the click event because you are not clicking on the actual
form you are clicking on an MDIClient.
This is the last control in the control's collection of the form.
Attach the click event to this.
this.Controls[this.Controls.Count -1].Click += new EventHandler(Form1_Click);

Get location of CurrentCell in DataGridView

2009-05-07T08:57:00.002+03:00

want to manipulate the colors of DataGridViewCell's rectangle?
use this code to getthe rectangle

DataGridViewCell cc = this.dataGridView1.CurrentCell;
Rectangle rect = this.dataGridView1.GetCellDisplayRectangle(cc.ColumnIndex,
cc.RowIndex, true);

Embeding String as overlay on a bitmap

2009-05-07T08:50:00.004+03:00

want to write your own string as an overlay of a given bitmap?
Use this code

CFont* pFont = CFont::FromHandle((HFONT) GetStockObject(DEFAULT_GUI_FONT));
CFont* pOldFont = dc.SelectObject(pFont);
dc.SetTextColor(RGB(255,255,255));
dc.SetBkMode(TRANSPARENT);
dc.TextOut(500,397,"String");
dc.SelectObject(pOldFont);

save rectangle to JPEG

2009-05-05T08:46:00.002+03:00

When you need to save a rectangle in your program to a file
the im.Save( "c:\\image.jpg", ImageFormatJPEG); line determines the file format


#include  //For Image
using namespace Gdiplus; //For Image

void BitmapUtils::SaveBitmapToFile(HDC hdc,CRect rect)
{
 HDC hMemDC = CreateCompatibleDC(hdc);
 HBITMAP hBitmap = CreateCompatibleBitmap(hdc,rect.right, rect.Height() + rect.bottom);
 if (hBitmap)
 {
  HBITMAP hOld = (HBITMAP) SelectObject(hMemDC, hBitmap);
  BitBlt(hMemDC, 0, 0, rect.right, rect.Height() + rect.bottom, hdc, 0, 0, SRCCOPY);
  SelectObject(hMemDC, hOld);
  DeleteDC(hMemDC);
  ::ReleaseDC(NULL, hdc);
 }
 CImage im;
 im.Attach(hBitmap); 
 im.Save( "c:\\image.jpg", ImageFormatJPEG);
}

Obtaining a File Name From a File Handle

2009-05-04T11:05:00.002+03:00

Got a file handle and you want to get the file name?
Use this code

#include "windows.h"
#include "stdio.h"
#include "tchar.h"
#include "string.h"
#include "psapi.h"
#include "strsafe.h"

#define BUFSIZE 512


BOOL GetFileNameFromHandle(HANDLE hFile) 
{
  BOOL bSuccess = FALSE;
  TCHAR pszFilename[MAX_PATH+1];
  HANDLE hFileMap;

  // Get the file size.
  DWORD dwFileSizeHi = 0;
  DWORD dwFileSizeLo = GetFileSize(hFile, &dwFileSizeHi); 

  if( dwFileSizeLo == 0 && dwFileSizeHi == 0 )
  {
     printf("Cannot map a file with a length of zero.\n");
     return FALSE;
  }

  // Create a file mapping object.
  hFileMap = CreateFileMapping(hFile, 
                    NULL, 
                    PAGE_READONLY,
                    0, 
                    1,
                    NULL);

  if (hFileMap) 
  {
    // Create a file mapping to get the file name.
    void* pMem = MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, 1);

    if (pMem) 
    {
      if (GetMappedFileName (GetCurrentProcess(), 
                             pMem, 
                             pszFilename,
                             MAX_PATH)) 
      {

        // Translate path with device name to drive letters.
        TCHAR szTemp[BUFSIZE];
        szTemp[0] = '\0';

        if (GetLogicalDriveStrings(BUFSIZE-1, szTemp)) 
        {
          TCHAR szName[MAX_PATH];
          TCHAR szDrive[3] = TEXT(" :");
          BOOL bFound = FALSE;
          TCHAR* p = szTemp;

          do 
          {
            // Copy the drive letter to the template string
            *szDrive = *p;

            // Look up each device name
            if (QueryDosDevice(szDrive, szName, MAX_PATH))
            {
              UINT uNameLen = _tcslen(szName);

              if (uNameLen < MAX_PATH) 
              {
                bFound = _tcsnicmp(pszFilename, szName, 
                    uNameLen) == 0;

                if (bFound) 
                {
                  // Reconstruct pszFilename using szTempFile
                  // Replace device path with DOS path
                  TCHAR szTempFile[MAX_PATH];
                  StringCchPrintf(szTempFile,
                            MAX_PATH,
                            TEXT("%s%s"),
                            szDrive,
                            pszFilename+uNameLen);
                  StringCchCopyN(pszFilename, MAX_PATH+1, szTempFile, _tcslen(szTempFile));
                }
              }
            }

            // Go to the next NULL character.
            while (*p++);
          } while (!bFound && *p); // end of string
        }
      }
      bSuccess = TRUE;
      UnmapViewOfFile(pMem);
    } 

    CloseHandle(hFileMap);
  }
  _tprintf(TEXT("File name is %s\n"), pszFilename);
  return(bSuccess);
}

int _tmain(int argc, TCHAR *argv[])
{
    HANDLE hFile;

    if( argc != 2 )
    {
        printf("This sample takes a file name as a parameter.\n");
        return 0;
    }
    hFile = CreateFile(argv[1], GENERIC_READ, FILE_SHARE_READ, NULL,
        OPEN_EXISTING, 0, NULL);

    if(hFile == INVALID_HANDLE_VALUE)
    {
        printf("CreateFile failed with %d\n", GetLastError());
        return 0;
    }
    GetFileNameFromHandle( hFile );
}

Writing a bitmap to a BMP file

2009-05-04T09:07:00.003+03:00

Great function to save a bitmap structure to a file

// WriteDIB - Writes a DIB to file
// Returns - TRUE on success
// szFile - Name of file to write to
// hDIB - Handle of the DIB
BOOL WriteDIB( LPTSTR szFile, HANDLE hDIB)
{
BITMAPFILEHEADER hdr;
LPBITMAPINFOHEADER lpbi;

if (!hDIB)
return FALSE;

CFile file;
if( !file.Open( szFile, CFile::modeWrite|CFile::modeCreate) )
return FALSE;

lpbi = (LPBITMAPINFOHEADER)hDIB;

int nColors = 1 << lpbi->biBitCount;

// Fill in the fields of the file header
hdr.bfType = ((WORD) ('M' << 8) | 'B'); // is always "BM"
hdr.bfSize = GlobalSize (hDIB) + sizeof( hdr );
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
hdr.bfOffBits = (DWORD) (sizeof( hdr ) + lpbi->biSize +
nColors * sizeof(RGBQUAD));

// Write the file header
file.Write( &hdr, sizeof(hdr) );

// Write the DIB header and the bits
file.Write( lpbi, GlobalSize(hDIB) );

return TRUE;
}

USB handling in MFC - discovering , Ejecting

2009-05-03T14:46:00.016+03:00

inserted a usb and need to knowe which drive it occupies? want to eject a USB?
Use this:

the "*****" stand for the class you are using

Force USB Removal Project

Header file



static const GUID GUID_DEVCLASS_COMPUTER = 
{ 0x4D36E966, 0xE325, 0x11CE, { 0xBF, 0xC1, 0x08, 0x00, 0x2B, 0xE1, 0x03, 0x18} };

// Copy from HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceClasses
static const GUID GUID_DEVINTERFACE_LIST[] = 
{
 // GUID_DEVINTERFACE_USB_DEVICE
 { 0xA5DCBF10, 0x6530, 0x11D2, { 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED } },

  // GUID_DEVINTERFACE_DISK
 { 0x53f56307, 0xb6bf, 0x11d0, { 0x94, 0xf2, 0x00, 0xa0, 0xc9, 0x1e, 0xfb, 0x8b } },

 // GUID_DEVINTERFACE_HID, 
 { 0x4D1E55B2, 0xF16F, 0x11CF, { 0x88, 0xCB, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30 } },

 // GUID_NDIS_LAN_CLASS
 { 0xad498944, 0x762f, 0x11d0, { 0x8d, 0xcb, 0x00, 0xc0, 0x4f, 0xc3, 0x35, 0x8c } }

 };

private members:
SP_CLASSIMAGELIST_DATA m_imgList;

Link: Setupapi.lib

Source:

#include "winioctl.h"
#define MAX_DRIVES 26


BEGIN_MESSAGE_MAP(*****, CDialog)
//{{AFX_MSG_MAP(CRSDCDlg)
.
.
.
ON_MESSAGE(WM_DEVICECHANGE, OnMyDeviceChange)
ON_MESSAGE(WM_STATUS_MESAGE, OnStatusMessage)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()




*****::OnInitDialog()
{
     .
     .

 ZeroMemory(&m_imgList, sizeof(SP_CLASSIMAGELIST_DATA));
 m_imgList.cbSize = sizeof(SP_CLASSIMAGELIST_DATA);
 BOOL b = SetupDiGetClassImageList(&m_imgList);
 ASSERT(b);
 int nRootImg;
 b = SetupDiGetClassImageIndex(&m_imgList, &GUID_DEVCLASS_COMPUTER, &nRootImg);
 ASSERT(b);

 HDEVNOTIFY hDevNotify;
 DEV_BROADCAST_DEVICEINTERFACE NotificationFilter;
 ZeroMemory( &NotificationFilter, sizeof(NotificationFilter) );
 NotificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
 NotificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
 for(int i=0; i {
  NotificationFilter.dbcc_classguid = GUID_DEVINTERFACE_LIST[i];
  hDevNotify = RegisterDeviceNotification(this->GetSafeHwnd(), &NotificationFilter, DEVICE_NOTIFY_WINDOW_HANDLE);
  if( !hDevNotify ) {
   AfxMessageBox(CString("Can't register device notification: ") 
    + _com_error(GetLastError()).ErrorMessage(), MB_ICONEXCLAMATION);
   return FALSE;
  }
 }
      .
      .
}



//handle windows message regurding USB insertion

LRESULT *****::OnMyDeviceChange(WPARAM wParam, LPARAM lParam)
{
 if ( DBT_DEVICEARRIVAL == wParam || DBT_DEVICEREMOVECOMPLETE == wParam ) 
 {
  PDEV_BROADCAST_HDR pHdr = (PDEV_BROADCAST_HDR)lParam;
  PDEV_BROADCAST_DEVICEINTERFACE pDevInf;
  PDEV_BROADCAST_HANDLE pDevHnd;
  PDEV_BROADCAST_OEM pDevOem;
  PDEV_BROADCAST_PORT pDevPort;
  PDEV_BROADCAST_VOLUME pDevVolume;
  switch( pHdr->dbch_devicetype ) 
  {
   case DBT_DEVTYP_DEVICEINTERFACE:
    pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)pHdr;
    UpdateDevice(pDevInf, wParam);
    break;

   case DBT_DEVTYP_HANDLE:
    pDevHnd = (PDEV_BROADCAST_HANDLE)pHdr;
    break;

   case DBT_DEVTYP_OEM:
    pDevOem = (PDEV_BROADCAST_OEM)pHdr;
    break;

   case DBT_DEVTYP_PORT:
    pDevPort = (PDEV_BROADCAST_PORT)pHdr;
    break;

   case DBT_DEVTYP_VOLUME:
    pDevVolume = (PDEV_BROADCAST_VOLUME)pHdr;
    HandleDrive(pDevVolume->dbcv_unitmask);
    break;
  }
 }
 return 0;
}

// 

void *****::UpdateDevice(PDEV_BROADCAST_DEVICEINTERFACE pDevInf, WPARAM wParam)
{
 // pDevInf->dbcc_name: 
 // \\?\USB#Vid_04e8&Pid_503b#0002F9A9828E0F06#{a5dcbf10-6530-11d2-901f-00c04fb951ed}
 // szDevId: USB\Vid_04e8&Pid_503b\0002F9A9828E0F06
 // szClass: USB

 ASSERT(lstrlen(pDevInf->dbcc_name) > 4);
 CString szDevId = pDevInf->dbcc_name+4;
 int idx = szDevId.ReverseFind(_T('#'));
 ASSERT( -1 != idx );
 szDevId.Truncate(idx);
 szDevId.Replace(_T('#'), _T('\\'));
 szDevId.MakeUpper();

 CString szClass;
 idx = szDevId.Find(_T('\\'));
 ASSERT(-1 != idx );
 szClass = szDevId.Left(idx);
 if ( DBT_DEVICEARRIVAL == wParam ) 
 {
  //szTmp.Format(_T("Adding %s\r\n"), szDevId.GetBuffer());
  m_bAdding = true;
   printf("Adding %s\n", szDevId.GetBuffer());
 } else 
 {
  //szTmp.Format(_T("Removing %s\r\n"), szDevId.GetBuffer());
  m_bAdding =false;
   printf("Removing %s\n", szDevId.GetBuffer());
 }

 // seems we should ignore "ROOT" type....
 if ( _T("ROOT") == szClass ) 
 {
  return;
 }

 DWORD dwFlag = DBT_DEVICEARRIVAL != wParam ? 
DIGCF_ALLCLASSES : (DIGCF_ALLCLASSES | DIGCF_PRESENT);
 HDEVINFO hDevInfo = SetupDiGetClassDevs(NULL,szClass,NULL,dwFlag);
 if( INVALID_HANDLE_VALUE == hDevInfo ) 
 {
  AfxMessageBox(CString("SetupDiGetClassDevs(): ") 
   + _com_error(GetLastError()).ErrorMessage(), MB_ICONEXCLAMATION);
  return;
 }

 SP_DEVINFO_DATA spDevInfoData;
 if ( FindDevice(hDevInfo, szDevId, spDevInfoData) ) 
 {
  // OK, device found
  DWORD DataT ;
  TCHAR buf[MAX_PATH];
  DWORD nSize = 0;

  // get Friendly Name or Device Description
  if ( SetupDiGetDeviceRegistryProperty(hDevInfo, &spDevInfoData, 
   SPDRP_FRIENDLYNAME, &DataT, (PBYTE)buf, sizeof(buf), &nSize) ) 
  {
   printf("%s\n",GetClassDesc(&(spDevInfoData.ClassGuid)));
   
  } 
  else if ( SetupDiGetDeviceRegistryProperty(hDevInfo, &spDevInfoData, 
    SPDRP_DEVICEDESC, &DataT, (PBYTE)buf, sizeof(buf), &nSize) ) 
   {
    printf("%s\n",GetClassDesc(&(spDevInfoData.ClassGuid)));
   }
  else 
   {
     lstrcpy(buf, _T("Unknown"));
   }

   if(m_bAdding && GetClassDesc(&(spDevInfoData.ClassGuid)) == "Disk drives")
   {
     // drive was added handle this!!
     
   }
   else if(!m_bAdding) //remove
   {
     removeDevice(szDevId);
   }
   
 }
 SetupDiDestroyDeviceInfoList(hDevInfo);
}


BOOL *****::FindDevice(HDEVINFO& hDevInfo, 
         CString& szDevId, 
         SP_DEVINFO_DATA& spDevInfoData)
{
 spDevInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
 for(int i=0; SetupDiEnumDeviceInfo(hDevInfo, i, &spDevInfoData); i++) 
 {
  DWORD nSize=0 ;
  TCHAR buf[MAX_PATH];

  if ( !SetupDiGetDeviceInstanceId(hDevInfo, &spDevInfoData, buf, sizeof(buf), &nSize) ) 
  {
   printf(CString("SetupDiGetDeviceInstanceId(): ") 
    + _com_error(GetLastError()).ErrorMessage());
   return FALSE;
  } 
  if ( szDevId == buf ) {
   // OK, device found
   return TRUE;
  }
 }
 return FALSE;
}


CString *****::GetClassDesc(const GUID* pGuid)
{
 TCHAR buf[MAX_PATH];
 DWORD size;
 if ( SetupDiGetClassDescription(pGuid, buf, sizeof(buf), &size) ) {
  return CString(buf);
 } else {
  printf("Can't get class description: %s", _com_error(GetLastError()).ErrorMessage());
  return _T("");
 }
}

//disable the popup made via windows

void *****::UsbPopupDisable(CString sUSB)
{
  
  HDEVINFO hDevInfo = SetupDiGetClassDevs(NULL,NULL,NULL,DIGCF_ALLCLASSES);
  if( INVALID_HANDLE_VALUE == hDevInfo ) {
   AfxMessageBox(CString("SetupDiGetClassDevs(): ") 
    + _com_error(GetLastError()).ErrorMessage(), MB_ICONEXCLAMATION);
   return;
  }

  SP_PROPCHANGE_PARAMS spPropChangeParams;
  spPropChangeParams.ClassInstallHeader.cbSize = sizeof(SP_CLASSINSTALL_HEADER);
  spPropChangeParams.ClassInstallHeader.InstallFunction = DIF_PROPERTYCHANGE;
  spPropChangeParams.Scope = DICS_FLAG_GLOBAL;
  spPropChangeParams.StateChange = DICS_DISABLE;
  spPropChangeParams.HwProfile = 0;

  SP_DEVINFO_DATA spDevInfoData;
  if ( FindDevice(hDevInfo, sUSB, spDevInfoData) ) 
  {
   if ( !SetupDiSetClassInstallParams(hDevInfo, &spDevInfoData, 
    (SP_CLASSINSTALL_HEADER*)&spPropChangeParams, sizeof(spPropChangeParams)) ) 
   {
     AfxMessageBox(CString("SetupDiSetClassInstallParams(): ") 
      + _com_error(GetLastError()).ErrorMessage(), MB_ICONEXCLAMATION);
    } else if ( !SetupDiCallClassInstaller(DIF_PROPERTYCHANGE, hDevInfo, &spDevInfoData) ) 
   {
     AfxMessageBox(CString("SetupDiClassInstaller(): ") 
      + _com_error(GetLastError()).ErrorMessage(), MB_ICONEXCLAMATION);
    } else {
     AfxMessageBox(_T("Dislabe OK"), MB_OK);
    }
  }

  SetupDiDestroyDeviceInfoList(hDevInfo);
 
}

//Description  
//
//Finds the first valid drive letter from a mask of drive letters.  
//
//The mask must be in the format bit 0 = A, bit 1 = B, bit 3 = C,  
//
//etc. A valid drive letter is defined when the corresponding bit  
//
//is set to 1.  
//
//Returns the first drive letter that was found.  

char *****::FirstDriveFromMask (ULONG unitmask)  
{  
 char i;  
 for (i = 0; i < 26; ++i)  
 {  
  if (unitmask & 0x1)  
   break;  
  unitmask = unitmask >> 1;  
 }  
 return (i + 'A');  
}  

void *****::HandleDrive(ULONG unitmask)
{
 CFile   systemNameFile;
 CFileException fileError;
 CString sDrive;
 CString strFilePath;
 int  nSystemNameSize;
 CString strSystemName;

 char cSystemName[ MAX_SYSTEM_NAME ];
 sDrive.Format("%c:",FirstDriveFromMask(unitmask));
 printf("HandleDrive -%s\n",sDrive);

 bool bExisted =false;
 if(IsDriveAlreadyExist(sDrive,bExisted))
 {
  if(!bExisted)
  {
   printf("HandleDrive - %s already exist assuming removed\n",sDrive);
   return; //probably device is detaching
  }
  else // drive was there before the application started
  {
   removeDevice(sDrive,true);
  }
 }

 RSDC_Status * currentAvailableSlot;
 currentAvailableSlot = GetFirstAvailableSlot(true);
 if(!currentAvailableSlot)
  return;
 currentAvailableSlot->eStatus = USB_CONNECTED;
 currentAvailableSlot->strDriveName=sDrive;
 
 

 strFilePath =sDrive + BK_SLASH + SYSTEM_NAME_FILE;
 if ( systemNameFile.Open( strFilePath , CFile::modeRead , &fileError ) )
 {
  printf("HandleDrive - Read file %s\n",strFilePath);
  nSystemNameSize = systemNameFile.Read( cSystemName , MAX_SYSTEM_NAME );
  cSystemName[ nSystemNameSize ] = '\0'; // puts NULL at the end of the name
  strSystemName = A2T( cSystemName );
 
  // If it's new then it is still idle:

 }
 else
 {
  printf("Found drive but no System file - Read file %s\n",strFilePath);
 
 }
}

// Search for all of Hard drive devices in the system , and filter the USB's type 

void ******::SearchForAllDevices()
{
 HANDLE hHardDrive = INVALID_HANDLE_VALUE;  
 for(int i = 0; i< MAX_DRIVES; i++) 
 {
  CString sFormat;
  sFormat.Format("\\\\.\\%c:",'a'+i);
  if ((hHardDrive= CreateFile(sFormat,GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,OPEN_EXISTING,0,NULL)) == INVALID_HANDLE_VALUE)   
  {    
   CloseHandle(hHardDrive);
   continue;
  }     
  else   
  {    
   DISK_GEOMETRY geo;   
   STORAGE_HOTPLUG_INFO inf;
   //GET_MEDIA_TYPES media_types;
   DWORD dwSize = 0;    
   ZeroMemory(&geo,sizeof(geo));
   BOOL bRes = DeviceIoControl( hHardDrive, IOCTL_STORAGE_GET_HOTPLUG_INFO , NULL, 0, &inf, sizeof(STORAGE_HOTPLUG_INFO),&dwSize, NULL);      // the type of hard disk    //geo.MediaType  
   //bRes = DeviceIoControl(hHardDrive,IOCTL_STORAGE_GET_MEDIA_TYPES_EX,NULL,0,&media_types, sizeof(GET_MEDIA_TYPES),&dwSize, NULL);      // the type of hard disk    //geo.MediaType  
   bRes = DeviceIoControl( hHardDrive, IOCTL_DISK_GET_DRIVE_GEOMETRY , NULL, 0, &geo, sizeof(DISK_GEOMETRY),&dwSize, NULL);      // the type of hard disk    //geo.MediaType  
   CloseHandle(hHardDrive);
   if(bRes && (geo.MediaType == RemovableMedia ||  geo.MediaType == FixedMedia) && inf.DeviceHotplug )

   {
    printf("USB found on :%c:\n",'a'+i);
    
    }
    else
    {
     printf("Found drive but no System file - Read file %s\n",strFilePath);
     }
   }
  }
 }
}

HANDLE ******::OpenVolume(TCHAR cDriveLetter,BOOL &bIsFixedMedia)
{
 HANDLE hVolume;
 UINT uDriveType;
 TCHAR szVolumeName[8];
 TCHAR szRootName[5];
 DWORD dwAccessFlags;
 LPTSTR szVolumeFormat = TEXT("\\\\.\\%c:");
 LPTSTR szRootFormat = TEXT("%c:\\");

 wsprintf(szRootName, szRootFormat, cDriveLetter);

 uDriveType = GetDriveType(szRootName);
 bIsFixedMedia = DRIVE_FIXED == uDriveType;
 switch(uDriveType) {
    case DRIVE_REMOVABLE:
    case DRIVE_FIXED:
     dwAccessFlags = GENERIC_READ | GENERIC_WRITE;
     break;
    case DRIVE_CDROM:
     dwAccessFlags = GENERIC_READ;
     break;
    default:
     _tprintf(TEXT("Cannot eject.  Drive type is incorrect.\n"));
     return INVALID_HANDLE_VALUE;
 }

 wsprintf(szVolumeName, szVolumeFormat, cDriveLetter);

 hVolume = CreateFile(   szVolumeName,
  dwAccessFlags,
  FILE_SHARE_READ | FILE_SHARE_WRITE,
  NULL,
  OPEN_EXISTING,
  0,
  NULL );
 if (hVolume == INVALID_HANDLE_VALUE)
 {
  printf("Error Opening %s\n",szVolumeFormat);
 }

 return hVolume;
}

BOOL *******::CloseVolume(HANDLE hVolume)
{
 return CloseHandle(hVolume);
}

#define LOCK_TIMEOUT        10000       // 10 Seconds
#define LOCK_RETRIES        20

BOOL *******::LockVolume(HANDLE hVolume)
{
 DWORD dwBytesReturned;
 DWORD dwSleepAmount;
 int nTryCount;

 dwSleepAmount = LOCK_TIMEOUT / LOCK_RETRIES;

 // Do this in a loop until a timeout period has expired
 for (nTryCount = 0; nTryCount < LOCK_RETRIES; nTryCount++) {
  if (DeviceIoControl(hVolume,
   FSCTL_LOCK_VOLUME,
   NULL, 0,
   NULL, 0,
   &dwBytesReturned,
   NULL))
   return TRUE;

  Sleep(dwSleepAmount);
 }

 return FALSE;
}

BOOL *******::DismountVolume(HANDLE hVolume)
{
 DWORD dwBytesReturned;

 return DeviceIoControl( hVolume,
  FSCTL_DISMOUNT_VOLUME,
  NULL, 0,
  NULL, 0,
  &dwBytesReturned,
  NULL);
}

BOOL ********::PreventRemovalOfVolume(HANDLE hVolume, BOOL fPreventRemoval)
{
 DWORD dwBytesReturned;
 PREVENT_MEDIA_REMOVAL PMRBuffer;

 PMRBuffer.PreventMediaRemoval = fPreventRemoval;

 return DeviceIoControl( hVolume,
  IOCTL_STORAGE_MEDIA_REMOVAL,
  &PMRBuffer, sizeof(PREVENT_MEDIA_REMOVAL),
  NULL, 0,
  &dwBytesReturned,
  NULL);
}

BOOL *******::AutoEjectVolume(HANDLE hVolume)
{
 DWORD dwBytesReturned;

 return DeviceIoControl( hVolume,
  IOCTL_STORAGE_EJECT_MEDIA,
  NULL, 0,
  NULL, 0,
  &dwBytesReturned,
  NULL);
}


//************************************
// Description : Eject the USB device
//************************************
BOOL ******::EjectVolume(TCHAR cDriveLetter)
{
 HANDLE hVolume;

 BOOL fRemoveSafely = FALSE;
 BOOL fAutoEject = FALSE;
 BOOL bIsFixedMedia = FALSE;
 // Open the volume.
 hVolume = OpenVolume(cDriveLetter,bIsFixedMedia);

 if(bIsFixedMedia = TRUE)
 {
  if (hVolume == INVALID_HANDLE_VALUE)
   return FALSE;
  if (!CloseVolume(hVolume))
   return FALSE;

  //Eject the fixed drive
  HINSTANCE hDll;
  hDll = LoadLibrary("USBFixedDiskSafeRemoval");
  if(hDll == NULL)
  {
   return FALSE;
  }
  eject = (EJECT)GetProcAddress(hDll,"fnUSBFixedDiskSafeRemoval");
  int result;
  if(eject != NULL)
   result = (eject)(cDriveLetter);
  else
  {
   FreeLibrary(hDll);
   return FALSE;
  }
   FreeLibrary(hDll);
   return TRUE;
 }

 if (hVolume == INVALID_HANDLE_VALUE)
  return FALSE;

 // Lock and dismount the volume.
 if (LockVolume(hVolume) && DismountVolume(hVolume)) {
  fRemoveSafely = TRUE;

  // Set prevent removal to false and eject the volume.
  if (PreventRemovalOfVolume(hVolume, FALSE) &&
   AutoEjectVolume(hVolume))
   fAutoEject = TRUE;
 }

 // Close the volume so other processes can use the drive.
 if (!CloseVolume(hVolume))
  return FALSE;

 if (fAutoEject)
  printf("Media in Drive %c has been ejected safely.\n",
  cDriveLetter);
 else {
  if (fRemoveSafely)
   printf("Media in Drive %c can be safely removed.\n",
   cDriveLetter);
 }
 return TRUE;
}

Ensuring that only a single instance of a .NET application is running

2009-05-03T14:17:00.003+03:00

If you want to activate only one instance(.exe) of your application use this code in C#

using System.Diagnostics;

public static Process PriorProcess()
// Returns a System.Diagnostics.Process pointing to
// a pre-existing process with the same name as the
// current one, if any; or null if the current process
// is unique.
{
Process curr = Process.GetCurrentProcess();
Process[] procs = Process.GetProcessesByName(curr.ProcessName);
foreach (Process p in procs)
{
if ((p.Id != curr.Id) &&
(p.MainModule.FileName == curr.MainModule.FileName))
return p;
}
return null;
}
.
.
.
[STAThread]
static void Main() // args are OK here, of course
{
if (PriorProcess() != null)
{
MessageBox("Another instance is already running.");
return;
}
Application.Run(new Form1()); // or whatever was here
}

find out the size in pixels (width, height) of a QString

2009-05-03T14:04:00.003+03:00

Very useful when trying to determine the width or height of a string in case of control position.

QFontMetrics fm( someFont);
int w = fm.width( "String");
int h = fm.height();