使用C#,WPF,和DWM保存窗口的屏幕截图 [英] Saving a screenshot of a window using C#, WPF, and DWM
问题描述
这是一个跟进问题这个问题
以上的解决方案使用DWM显示活动窗口的缩略图。如果我理解正确的话,它的工作原理是让你指定要查看应用程序的窗口句柄,然后有你提供了一个窗口句柄,并在那里有窗户应拉上目标窗口的内容,该窗口上的位置。
The solution to the above uses DWM to display a thumbnail of an active window. If I understand correctly, it works by letting you specify the window handle of the application you want to view and then having you provide a window handle and a location on that window where windows should draw the contents of the target Window.
有没有办法来渲染窗口屏幕快照直接的BitmapImage或图像,而不是直接借鉴的地方在你的窗口?
Is there a way to render the window screen shot directly to BitmapImage or Image instead of directly drawing it somewhere in your window? (Basically to just grab a screen shot of the window - even if it's covered by another window - with out using an updating thumbnail.)
感谢您的帮助(使用更新缩略图与出基本上只抢窗口的屏幕快照 - - 哪怕它是由另一个窗口覆盖。)!
Thanks for you help!
推荐答案
该Control.DrawToBitmap并不总是工作,所以我使出提供更一致的结果下面的原生API调用:
The Control.DrawToBitmap doesn't always work so I resorted to the following native API calls that provide more consistent results:
该实用程序类。呼叫Utilities.CaptureWindow(Control.Handle)来捕获特定的控制:
The Utilities class. Call Utilities.CaptureWindow(Control.Handle) to capture a specific control:
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类:
The Gdi32 class:
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类:
The User32 class:
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);
}
使用的常量:
The constants used:
public const int SRCCOPY = 13369376;
所使用的结构:
The structs used:
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
一个友好的控制扩展方法:
A friendly Control extension method:
public static class ControlExtensions
{
public static Image DrawToImage(this Control control)
{
return Utilities.CaptureWindow(control.Handle);
}
}
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