Hej hur tar man en skärmbump i C# och kan man begrännsa den till bara vissa belar av skärrmen eller måste man ta hela??
Kan man på ett automatiskt sätt jämföra två skärmbilder för att avgöra om de är identiska ??

MVH Henrik Larsson

<code>
public static Bitmap CaptureScreen()
{
Bitmap _objBMP = ScreenCapture.GetDesktopImage();
//Här kan du lägga bilden i en rapport
rptGeneralPrint _rpt = new rptGeneralPrint();
_rpt.pic1.Image = _objBMP;
return _objBMP;
}
///
/// This class shall keep the GDI32 APIs used in our program.
///
private class PlatformInvokeGDI32
{
public const int SRCCOPY = 13369376;

[DllImport("gdi32.dll",EntryPoint="DeleteDC")]
public static extern IntPtr DeleteDC(IntPtr hDc);

[DllImport("gdi32.dll",EntryPoint="DeleteObject")]
public static extern IntPtr DeleteObject(IntPtr hDc);

[DllImport("gdi32.dll",EntryPoint="BitBlt")]
public static extern bool BitBlt(IntPtr hdcDest,int xDest,
int yDest,int wDest,
int hDest,IntPtr hdcSource,
int xSrc,int ySrc,int RasterOp);

[DllImport ("gdi32.dll",EntryPoint="CreateCompatibleBitmap")]
public static extern IntPtr CreateCompatibleBitmap
(IntPtr hdc,int nWidth, int nHeight);

[DllImport ("gdi32.dll",EntryPoint="CreateCompatibleDC")]
public static extern IntPtr CreateCompatibleDC(IntPtr hdc);

[DllImport ("gdi32.dll",EntryPoint="SelectObject")]
public static extern IntPtr SelectObject(IntPtr hdc,IntPtr bmp);

}

///
/// This class shall keep the User32 APIs used in our program.
///
private class PlatformInvokeUSER32
{
public const int SM_CXSCREEN=0;
public const int SM_CYSCREEN=1;


[DllImport("user32.dll", EntryPoint="GetDesktopWindow")]
public static extern IntPtr GetDesktopWindow();

[DllImport("user32.dll",EntryPoint="GetDC")]
public static extern IntPtr GetDC(IntPtr ptr);

[DllImport("user32.dll",EntryPoint="GetSystemMetrics")]
public static extern int GetSystemMetrics(int abc);

[DllImport("user32.dll",EntryPoint="GetWindowDC")]
public static extern IntPtr GetWindowDC(Int32 ptr);

[DllImport("user32.dll",EntryPoint="ReleaseDC")]
public static extern IntPtr ReleaseDC(IntPtr hWnd,IntPtr hDc);

}

///
/// This class shall keep all the functionality for capturing
/// the desktop.
///
private class ScreenCapture
{
public static Bitmap GetDesktopImage()
{
//In size variable we shall keep the size of the screen.
SIZE size;

//Variable to keep the handle to bitmap.
IntPtr hBitmap;

//Here we get the handle to the desktop device context.
IntPtr hDC = PlatformInvokeUSER32.GetDC
(PlatformInvokeUSER32.GetDesktopWindow());

//Here we make a compatible device context in memory for screen
//device context.
IntPtr hMemDC = PlatformInvokeGDI32.CreateCompatibleDC(hDC);

//We pass SM_CXSCREEN constant to GetSystemMetrics to get the
//X coordinates of the screen.
size.cx = PlatformInvokeUSER32.GetSystemMetrics
(PlatformInvokeUSER32.SM_CXSCREEN);

//We pass SM_CYSCREEN constant to GetSystemMetrics to get the
//Y coordinates of the screen.
size.cy = PlatformInvokeUSER32.GetSystemMetrics
(PlatformInvokeUSER32.SM_CYSCREEN);

//We create a compatible bitmap of the screen size and using
//the screen device context.
hBitmap = PlatformInvokeGDI32.CreateCompatibleBitmap
(hDC, size.cx, size.cy);

//As hBitmap is IntPtr, we cannot check it against null.
//For this purpose, IntPtr.Zero is used.
if (hBitmap!=IntPtr.Zero)
{
//Here we select the compatible bitmap in the memeory device
//context and keep the refrence to the old bitmap.
IntPtr hOld = (IntPtr) PlatformInvokeGDI32.SelectObject
(hMemDC, hBitmap);
//We copy the Bitmap to the memory device context.
PlatformInvokeGDI32.BitBlt(hMemDC, 0, 0,size.cx,size.cy, hDC,
0, 0,PlatformInvokeGDI32.SRCCOPY);
//We select the old bitmap back to the memory device context.
PlatformInvokeGDI32.SelectObject(hMemDC, hOld);
//We delete the memory device context.
PlatformInvokeGDI32.DeleteDC(hMemDC);
//We release the screen device context.
PlatformInvokeUSER32.ReleaseDC(PlatformInvokeUSER32.
GetDesktopWindow(), hDC);
//Image is created by Image bitmap handle and stored in
//local variable.
Bitmap bmp = System.Drawing.Image.FromHbitmap(hBitmap);
//Release the memory to avoid memory leaks.
PlatformInvokeGDI32.DeleteObject(hBitmap);
//This statement runs the garbage collector manually.
GC.Collect();
//Return the bitmap
return bmp;
}
//If hBitmap is null, retun null.
return null;
}
}

//This structure shall be used to keep the size of the screen.
private struct SIZE
{
public int cx;
public int cy;
}
</code>



//Jenny

Tack för lösningen med detta är en välldigt minneskrävande lösning att använda API på detta sätt. Finns det ingen smidigare lösning.