c# 根据句柄截取指定窗口的图片并保存 我要完整代码

在 C# 中，你可以使用 `Windows Presentation Foundation` (WPF) 和 `InteropServices` 来截取 Windows 窗口的图片并保存到文件。这里是一个基本示例，展示如何通过句柄获取窗口的屏幕截图：

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Interop;

namespace CaptureWindowImage
{
    public class WindowCapture
    {
        [DllImport("user32.dll", SetLastError = true)]
        private static extern IntPtr FindWindow(string className, string windowText);

        [DllImport("user32.dll")]
        private static extern bool GetWindowDC(IntPtr hWnd);
        
        [DllImport("gdi32.dll")]
        private static extern IntPtr CreateCompatibleDC(IntPtr hdc);
        
        [DllImport("gdi32.dll")]
        private static extern int SelectObject(IntPtr hdc, IntPtr hObject);
        
        [DllImport("gdi32.dll")]
        private static extern int GetDeviceCaps(IntPtr hdc, int nIndex);
        
        [DllImport("gdi32.dll")]
        private static extern IntPtr CreateBitmap(int width, int height, int bitCount, int bytesPerLine, IntPtr lpBits);
        
        [DllImport("gdi32.dll")]
        private static extern bool DeleteObject(IntPtr hObject);
        
        [DllImport("user32.dll")]
        private static extern bool ReleaseDC(IntPtr hWnd, IntPtr hdc);

        public static void CaptureWindowImage(string className, string windowText, string outputFilePath)
        {
            // 找到指定窗口的句柄
            IntPtr hwnd = FindWindow(className, windowText);

            if (hwnd == IntPtr.Zero)
            {
                Console.WriteLine($"未能找到名为 '{className}' 的窗口");
                return;
            }

            try
            {
                // 获取窗口的设备上下文
                IntPtr hdcWindow = GetWindowDC(hwnd);
                
                // 创建兼容设备上下文
                IntPtr hdcScreen = CreateCompatibleDC(hdcWindow);

                // 获取屏幕宽度和高度
                int width = GetDeviceCaps(hdcScreen, DeviceCap.Width);
                int height = GetDeviceCaps(hdcScreen, DeviceCap.Height);

                // 创建位图
                IntPtr bitmap = CreateBitmap(width, height, PixelFormat.Format32bppArgb, 0, IntPtr.Zero);

                // 将位图选择到设备上下文中
                SelectObject(hdcScreen, bitmap);

                // 偷窥窗口
                CopyFromScreen(hwnd, Point.Empty, Point.Zero, new Size(width, height), CopyPixelOperation.SourceCopy);

                // 保存位图到文件
                using (System.Drawing.Bitmap screenBitmap = new Bitmap(bitmap))
                {
                    screenBitmap.Save(outputFilePath, ImageFormat.Png);
                }

                // 清理资源
                DeleteObject(bitmap);
                ReleaseDC(hwnd, hdcWindow);
                DeleteDC(hdcScreen);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"捕获窗口图像失败: {ex.Message}");
            }
        }
    }
}

// 使用示例
string className = "YourClassName"; // 替换为你需要截取窗口的类名
string windowTitle = "YourWindowTitle"; // 替换为你需要截取窗口的标题
string outputFile = "screenshot.png";
WindowCapture.CaptureWindowImage(className, windowTitle, outputFile);