保存使用C＃，WPF，並且DWM

Question

的窗口的屏幕截圖這是一個後續問題this question

上述的解決方案使用DWM以顯示活動窗口的縮略圖。如果我理解正確，它可以讓你指定要查看的應用程序的窗口句柄，然後讓你提供一個窗口句柄和窗口上的窗口應該繪製目標窗口內容的位置。

有沒有辦法將窗口屏幕截圖直接呈現給BitmapImage或Image，而不是直接在窗口中的某處繪製它？ （基本上只需抓住窗口的屏幕截圖 - 即使它被另一個窗口覆蓋 - 不使用更新縮略圖。）

感謝您的幫助！

Answer 1

使用Control.DrawToBitmap Method

Image img = myForm.DrawToBitmap(); 
Image img = myPanel.DrawToBitmap(); 

Answer 2

的Control.DrawToBitmap並不總是工作，所以我使出提供更一致的結果下面的原生API調用：

的實用工具類。調用Utilities.CaptureWindow（Control.Handle）來捕獲特定的控制：

public static class Utilities 
{ 
    public static Image CaptureScreen() 
    { 
     return CaptureWindow(User32.GetDesktopWindow()); 
    } 

    public static Image CaptureWindow(IntPtr handle) 
    { 

     IntPtr hdcSrc = User32.GetWindowDC(handle); 

     RECT windowRect = new RECT(); 
     User32.GetWindowRect(handle, ref windowRect); 

     int width = windowRect.right - windowRect.left; 
     int height = windowRect.bottom - windowRect.top; 

     IntPtr hdcDest = Gdi32.CreateCompatibleDC(hdcSrc); 
     IntPtr hBitmap = Gdi32.CreateCompatibleBitmap(hdcSrc, width, height); 

     IntPtr hOld = Gdi32.SelectObject(hdcDest, hBitmap); 
     Gdi32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, ApiConstants.SRCCOPY); 
     Gdi32.SelectObject(hdcDest, hOld); 
     Gdi32.DeleteDC(hdcDest); 
     User32.ReleaseDC(handle, hdcSrc); 

     Image image = Image.FromHbitmap(hBitmap); 
     Gdi32.DeleteObject(hBitmap); 

     return image; 
    } 
} 

的GDI32類：

public class Gdi32 
{ 
    [DllImport("gdi32.dll")] 
    public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hObjectSource, int nXSrc, int nYSrc, int dwRop); 
    [DllImport("gdi32.dll")] 
    public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth, int nHeight); 
    [DllImport("gdi32.dll")] 
    public static extern IntPtr CreateCompatibleDC(IntPtr hDC); 
    [DllImport("gdi32.dll")] 
    public static extern bool DeleteDC(IntPtr hDC); 
    [DllImport("gdi32.dll")] 
    public static extern bool DeleteObject(IntPtr hObject); 
    [DllImport("gdi32.dll")] 
    public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject); 
} 

的USER32類：

public static class User32 
{ 
    [DllImport("user32.dll")] 
    public static extern IntPtr GetDesktopWindow(); 
    [DllImport("user32.dll")] 
    public static extern IntPtr GetWindowDC(IntPtr hWnd); 
    [DllImport("user32.dll")] 
    public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect); 
    [DllImport("user32.dll")] 
    public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC); 
} 

使用的常數：

public const int SRCCOPY = 13369376; 

T他用結構：

[StructLayout(LayoutKind.Sequential)] 
public struct RECT 
{ 
    public int left; 
    public int top; 
    public int right; 
    public int bottom; 
} 

友好的控制擴展方法：

public static class ControlExtensions 
{ 
    public static Image DrawToImage(this Control control) 
    { 
     return Utilities.CaptureWindow(control.Handle); 
    } 
}