获取特定应用程序的屏幕截图

我知道我可以使用Graphics.CopyFromScreen（）获取整个屏幕的屏幕截图。 但是，如果我只想要特定应用程序的屏幕截图呢？

Answer 1

这里有一些代码可以让你开始：

public void CaptureApplication(string procName) { var proc = Process.GetProcessesByName(procName)[0]; var rect = new User32.Rect(); User32.GetWindowRect(proc.MainWindowHandle, ref rect); int width = rect.right - rect.left; int height = rect.bottom - rect.top; var bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb); Graphics graphics = Graphics.FromImage(bmp); graphics.CopyFromScreen(rect.left, rect.top, 0, 0, new Size(width, height), CopyPixelOperation.SourceCopy); bmp.Save("c:\\tmp\\test.png", ImageFormat.Png); } private class User32 { [StructLayout(LayoutKind.Sequential)] public struct Rect { public int left; public int top; public int right; public int bottom; } [DllImport("user32.dll")] public static extern IntPtr GetWindowRect(IntPtr hWnd, ref Rect rect); } 

它工作，但需要改进：

• 你可能想要使用不同的机制来获得进程句柄（或者至less做一些防御性编码）
• 如果你的目标窗口不在前台，你将得到一个正确的大小/位置的截图，但是只要在前台填充任何东西就可以了（你可能想先把给定的窗口拉到前台）
• 除了将bmp保存到临时目录之外，您可能还想做其他的事情

Answer 2

PrintWindow win32 api将捕获窗口位图，即使该窗口被其他窗口覆盖，或者它在屏幕之外：

 [DllImport("user32.dll")] public static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect); [DllImport("user32.dll")] public static extern bool PrintWindow(IntPtr hWnd, IntPtr hdcBlt, int nFlags); public static Bitmap PrintWindow(IntPtr hwnd) { RECT rc; GetWindowRect(hwnd, out rc); Bitmap bmp = new Bitmap(rc.Width, rc.Height, PixelFormat.Format32bppArgb); Graphics gfxBmp = Graphics.FromImage(bmp); IntPtr hdcBitmap = gfxBmp.GetHdc(); PrintWindow(hwnd, hdcBitmap, 0); gfxBmp.ReleaseHdc(hdcBitmap); gfxBmp.Dispose(); return bmp; } 

上面RECT的参考可以用下面的类来解决：

 [StructLayout(LayoutKind.Sequential)] public struct RECT { private int _Left; private int _Top; private int _Right; private int _Bottom; public RECT(RECT Rectangle) : this(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom) { } public RECT(int Left, int Top, int Right, int Bottom) { _Left = Left; _Top = Top; _Right = Right; _Bottom = Bottom; } public int X { get { return _Left; } set { _Left = value; } } public int Y { get { return _Top; } set { _Top = value; } } public int Left { get { return _Left; } set { _Left = value; } } public int Top { get { return _Top; } set { _Top = value; } } public int Right { get { return _Right; } set { _Right = value; } } public int Bottom { get { return _Bottom; } set { _Bottom = value; } } public int Height { get { return _Bottom - _Top; } set { _Bottom = value + _Top; } } public int Width { get { return _Right - _Left; } set { _Right = value + _Left; } } public Point Location { get { return new Point(Left, Top); } set { _Left = value.X; _Top = value.Y; } } public Size Size { get { return new Size(Width, Height); } set { _Right = value.Width + _Left; _Bottom = value.Height + _Top; } } public static implicit operator Rectangle(RECT Rectangle) { return new Rectangle(Rectangle.Left, Rectangle.Top, Rectangle.Width, Rectangle.Height); } public static implicit operator RECT(Rectangle Rectangle) { return new RECT(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom); } public static bool operator ==(RECT Rectangle1, RECT Rectangle2) { return Rectangle1.Equals(Rectangle2); } public static bool operator !=(RECT Rectangle1, RECT Rectangle2) { return !Rectangle1.Equals(Rectangle2); } public override string ToString() { return "{Left: " + _Left + "; " + "Top: " + _Top + "; Right: " + _Right + "; Bottom: " + _Bottom + "}"; } public override int GetHashCode() { return ToString().GetHashCode(); } public bool Equals(RECT Rectangle) { return Rectangle.Left == _Left && Rectangle.Top == _Top && Rectangle.Right == _Right && Rectangle.Bottom == _Bottom; } public override bool Equals(object Object) { if (Object is RECT) { return Equals((RECT)Object); } else if (Object is Rectangle) { return Equals(new RECT((Rectangle)Object)); } return false; } } 

Answer 3

根据Alconja的回答，我做了一些改进：

 [StructLayout(LayoutKind.Sequential)] public struct Rect { public int left; public int top; public int right; public int bottom; } [DllImport("user32.dll")] private static extern int SetForegroundWindow(IntPtr hWnd); private const int SW_RESTORE = 9; [DllImport("user32.dll")] private static extern IntPtr ShowWindow(IntPtr hWnd, int nCmdShow); [DllImport("user32.dll")] public static extern IntPtr GetWindowRect(IntPtr hWnd, ref Rect rect); public Bitmap CaptureApplication(string procName) { Process proc; // Cater for cases when the process can't be located. try { proc = Process.GetProcessesByName(procName)[0]; } catch (IndexOutOfRangeException e) { return null; } // You need to focus on the application SetForegroundWindow(proc.MainWindowHandle); ShowWindow(proc.MainWindowHandle, SW_RESTORE); // You need some amount of delay, but 1 second may be overkill Thread.Sleep(1000); Rect rect = new Rect(); IntPtr error = GetWindowRect(proc.MainWindowHandle, ref rect); // sometimes it gives error. while (error == (IntPtr)0) { error = GetWindowRect(proc.MainWindowHandle, ref rect); } int width = rect.right - rect.left; int height = rect.bottom - rect.top; Bitmap bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb); Graphics.FromImage(bmp).CopyFromScreen(rect.left, rect.top, 0, 0, new Size(width, height), CopyPixelOperation.SourceCopy); return bmp; } 

Answer 4

你可以看看P /调用 win32的方式来做到这一点， 这篇文章就是这样的 …。

基本上，经历了将DC设置为位图并将WM_PRINT发送到有问题的应用程序窗口的麻烦。 它的相当讨厌，都告诉，但可能为你工作。

您可能需要的函数： SendMessage ， GetDC ， CreateCompatibleBitmp和SelectObject 。

我不能说我曾经这样做过，但是这是我如何解决这个问题。 （好吧，我可能会用纯粹的C语言来完成，但仍然是这样，大致就是我要攻击它的方式）。