/// <summary>
/// 截取指定句柄窗口的图像, 也可也截屏
/// <para>当然 当前封装是依赖传入参数获取窗口大小，也可以使用API自动获取</para>
/// <para>该方法可以直接生成缩略图， 通过 widthDest 和 heightDest 置顶缩略图宽高</para>
/// </summary>
/// <param name="handle"></param>
/// <param name="widthSrc"></param>
/// <param name="heightSrc"></param>
/// <param name="widthDest"></param>
/// <param name="heightDest"></param>
/// <returns></returns>
public static Bitmap CaptureWindow(IntPtr handle, int widthSrc, int heightSrc, int widthDest, int heightDest)
{
try
{
// get the hDC of the target window
IntPtr hdcSrc = User32.GetWindowDC(handle);
// create a device context we can copy to
IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);
// create a bitmap we can copy it to,
// using GetDeviceCaps to get the width/height
IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, widthDest, heightDest);
// select the bitmap object
IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);
// 设置高质量的缩放模式
GDI32.SetStretchBltMode(hdcDest, GDI32.STRETCH_HALFTONE);
// 如果 缩放模式设置为 GDI32.STRETCH_HALFTONE， 则必须调用下面的方法
GDI32.POINTAPI point;
GDI32.SetBrushOrgEx(hdcDest, 0, 0, out point);
// bitblt over
GDI32.StretchBlt(hdcDest, 0, 0, widthDest, heightDest, hdcSrc, 0, 0, widthSrc, heightSrc, GDI32.SRCCOPY);
// restore selection
GDI32.SelectObject(hdcDest, hOld);
// clean up
GDI32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
// get a .NET image object for it
Bitmap img = Image.FromHbitmap(hBitmap);
// free up the Bitmap object
GDI32.DeleteObject(hBitmap);
return(img);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return(null);
}