如何获取 C# 中特定 window 的屏幕截图？

Question

我使用 C# 中的 Graphics class 编写了一个截取屏幕截图的代码。 编码-

Bitmap bitmapScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Width, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
Graphics graphicsScreenshot = Graphics.FromImage(bitmapScreenshot);
graphicsScreenshot.CopyFromScreen(0, 0, 0, 0, Screen.PrimaryScreen.Bounds.Size);

虽然我找不到对任何打开的应用程序/窗口执行相同操作的方法，但有没有办法使用图形 class 来执行此操作，如果不在图形 class 中，我该怎么做？ 任何帮助表示赞赏。

Answer 1

您需要将您希望截屏的目标应用程序 window 带到前台，如下所示：

[DllImport("USER32.DLL", CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(String lpClassName, String lpWindowName);

[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);

public static void bringToFront(string title) {
    // Get a handle to the Calculator application.
    IntPtr handle = FindWindow(null, title);

    // Verify that Calculator is a running process.
    if (handle == IntPtr.Zero) {
        return;
    }

    // Make Calculator the foreground application
    SetForegroundWindow(handle);
}

一旦 window 位于前台，您可以截屏，这样您的代码将如下所示：

bringToFront("<Your target app window name>");
Bitmap bitmapScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Width, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
Graphics graphicsScreenshot = Graphics.FromImage(bitmapScreenshot);
graphicsScreenshot.CopyFromScreen(0, 0, 0, 0, Screen.PrimaryScreen.Bounds.Size);