GDI+使用GetHBitmap (WPF4/ c#)的通用错误

我使用以下代码捕获屏幕并将其复制到BitmapSource中。该方法通过DispatcherTimer每400ms连续调用一次。首先，我在。net Framework 3.5中使用这些代码，然后切换到Framework 4.0。当程序运行了一段时间(假设是15分钟)，它突然崩溃，在调用GetHBitmap时出现"GDI+中的通用错误"。

当我切换到。net 4.0时，我不得不注释掉CloseHandle()调用，它会抛出一个SEHException。

这是我的代码。我希望有人能帮忙…

// The code is based on an example by Charles Petzold
// http://www.charlespetzold.com/pwcs/ReadingPixelsFromTheScreen.html
// Import external Win32 functions
// BitBlt is used for the bit by bit block copy of the screen content
[DllImport("gdi32.dll")]
private static extern bool BitBlt(IntPtr hdcDst, int xDst, int yDst, int cx, int cy,
                                    IntPtr hdcSrc, int xSrc, int ySrc, uint ulRop);
// DeleteObject is used to delete the bitmap handle
[DllImport("gdi32.dll")]
private static extern bool DeleteObject(IntPtr hObject);
// CreateDC is used to create a graphics handle to the screen
[DllImport("gdi32.dll")]
private static extern IntPtr CreateDC(string lpszDriver, string lpszDevice, string lpszOutput, IntPtr lpInitData);
// CloseHandle is used to close the bitmap handle, which does not work with Framework 4 :(
// [DllImport("Kernel32")]
// private static extern bool CloseHandle(IntPtr handle);
public static void getBitmap(ref BitmapSource bms)
{
    // define the raster-operation code for the BitBlt method
    // SRCOPY copies the source directly to the destination
    const int SRCCOPY = 0x00CC0020;
    // The screenshot will be stored here
    Bitmap bm;
    // Get a Graphics object associated with the screen
    Screen s = UIHelper.getScreenHandle();
    Graphics grfxScreen = Graphics.FromHdc(CreateDC(null, s.DeviceName, null,
        IntPtr.Zero));
    // Create a bitmap the size of the screen.
    bm = new Bitmap((int)grfxScreen.VisibleClipBounds.Width,
                    (int)grfxScreen.VisibleClipBounds.Height, grfxScreen);
    // Create a Graphics object associated with the bitmap
    Graphics grfxBitmap = Graphics.FromImage(bm);
    // Get handles associated with the Graphics objects
    IntPtr hdcScreen = grfxScreen.GetHdc();
    IntPtr hdcBitmap = grfxBitmap.GetHdc();
    // Do the bitblt from the screen to the bitmap
    BitBlt(hdcBitmap, 0, 0, bm.Width, bm.Height,
            hdcScreen, 0, 0, SRCCOPY);
    // Release the device contexts.
    grfxBitmap.ReleaseHdc(hdcBitmap);
    grfxScreen.ReleaseHdc(hdcScreen);
    // convert the Bitmap to BitmapSource
    IntPtr hBitmap = bm.GetHbitmap();         // Application crashes here after a while...
    //System.Runtime.InteropServices.ExternalException was unhandled
    //  Message=Generic Error in GDI+.
    //  Source=System.Drawing
    //  ErrorCode=-2147467259
    //  StackTrace:
    //       at System.Drawing.Bitmap.GetHbitmap(Color background)
    //       at System.Drawing.Bitmap.GetHbitmap()
    if (bms != null) bms = null; // Dispose bms if it holds content
    bms = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
        hBitmap,
        IntPtr.Zero,
        Int32Rect.Empty,
        System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
    // tidy up
    // CloseHandle throws SEHException using Framework 4
    // CloseHandle(hBitmap);
    DeleteObject(hBitmap);
    hBitmap = IntPtr.Zero;
    bm.Dispose();
    hdcBitmap = IntPtr.Zero;
    hdcScreen = IntPtr.Zero;
    grfxBitmap.Dispose();
    grfxScreen.Dispose();
    GC.Collect();
}

using System.Drawing.Imaging;

private static Bitmap bmp;
private static Graphics gfx;

bmp = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
gfx = Graphics.FromImage(bmp);
gfx.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);

[DllImport("gdi32.dll")]
static extern bool BitBlt(IntPtr hdcDest, int xDest, int yDest, int
wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, CopyPixelOperation rop);
[DllImport("gdi32.dll")]
static extern IntPtr DeleteDC(IntPtr hDc);
[DllImport("gdi32.dll")]
static extern IntPtr DeleteObject(IntPtr hDc);
[DllImport("gdi32.dll")]
static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int nWidth, int nHeight);
[DllImport("gdi32.dll")]
static extern IntPtr CreateCompatibleDC(IntPtr hdc);
[DllImport("gdi32.dll")]
static extern IntPtr SelectObject(IntPtr hdc, IntPtr bmp);
[DllImport("gdi32.dll")]
private static extern IntPtr CreateDC(string lpszDriver, string lpszDevice, string lpszOutput, IntPtr lpInitData);
// get the screen handle and size
Screen s = UIHelper.getScreenHandle();
Size sz = s.Bounds.Size;
// capture the screen
IntPtr hSrce = CreateDC(null, s.DeviceName, null, IntPtr.Zero);
IntPtr hDest = CreateCompatibleDC(hSrce);
IntPtr hBmp = CreateCompatibleBitmap(hSrce, sz.Width, sz.Height);
IntPtr hOldBmp = SelectObject(hDest, hBmp);
bool b = BitBlt(hDest, 0, 0, sz.Width, sz.Height, hSrce, 0, 0, CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt);
Bitmap bm = Bitmap.FromHbitmap(hBmp);
SelectObject(hDest, hOldBmp);
// convert the Bitmap to BitmapSource
IntPtr hBitmap = bm.GetHbitmap();
// Dispose bms if it holds content, Garbage Collector will do the cleaning
if (bms != null) bms = null;
// create BitmapSource from Bitmap
bms = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
    hBitmap,
    IntPtr.Zero,
    Int32Rect.Empty,
    System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
// tidy up
// CloseHandle throws SEHException using Framework 4
// CloseHandle(hBitmap);
DeleteObject(hBitmap);
hBitmap = IntPtr.Zero;
DeleteObject(hBmp);
DeleteDC(hDest);
DeleteDC(hSrce);
bm.Dispose();
GC.Collect();