我正在使用具有4个输出（监视器）的系统，例如，每个输出1280x1024像素。我需要整个桌面和所有打开的应用程序的屏幕截图。
我试过了GetDesktopWindow() (MSDN)但它没有正常工作。有些表格没有显示在拍摄的图片上。
答案 0 :(得分：24)
我尝试过GetDesktopWindow（）函数，但它无法正常工作。
当然不是。
GetDesktopWindow函数将句柄返回到桌面窗口。它与捕获该窗口的图像没有任何关系。
此外，桌面窗口与“整个屏幕”不同。它特指桌面窗口。有关详细信息，请参阅this article，以及滥用此函数返回的句柄时可能出现的问题。
我正在使用一个系统，每个输出有4个输出（显示器）和1280x1024（例如）。我需要整个桌面和所有打开的应用程序的截图。
使用Graphics.CopyFromScreen方法在.NET Framework中执行此操作相对简单。你甚至不需要做任何P / Invoke！
在这种情况下，唯一的技巧是确保传递适当的尺寸。由于您有4个监视器，因此仅传递主屏幕的尺寸将不起作用。您需要传递整个虚拟屏幕的尺寸，其中包含所有显示器。通过查询SystemInformation.VirtualScreen属性来检索它，该属性返回虚拟屏幕的边界。如文档所示，这是多监视器系统上整个桌面的界限。
示例代码：
// Determine the size of the "virtual screen", which includes all monitors.
int screenLeft = SystemInformation.VirtualScreen.Left;
int screenTop = SystemInformation.VirtualScreen.Top;
int screenWidth = SystemInformation.VirtualScreen.Width;
int screenHeight = SystemInformation.VirtualScreen.Height;
// Create a bitmap of the appropriate size to receive the screenshot.
using (Bitmap bmp = new Bitmap(screenWidth, screenHeight))
{
// Draw the screenshot into our bitmap.
using (Graphics g = Graphics.FromImage(bmp))
{
g.CopyFromScreen(screenLeft, screenTop, 0, 0, bmp.Size);
}
// Do something with the Bitmap here, like save it to a file:
bmp.Save(savePath, ImageFormat.Jpeg);
}
修改
请在不是主线程的线程中使用wpf应用程序检查您的解决方案。我尝试过这个。它不起作用！
嗯，我没有在问题上看到WPF标签，也没有在身体的任何地方提到过。
不管怎样。我发布的代码在WPF应用程序中运行得很好，只要添加适当的引用并使用声明即可。您需要System.Windows.Forms和System.Drawing。可能有更多的WPF方式这样做，不需要依赖这些WinForms程序集，但我不知道它是什么。
它甚至适用于另一个线程。这里没有任何东西需要UI线程。
是的，我测试了它。这是我的完整测试代码：
using System.Windows;
using System.Windows.Forms; // also requires a reference to this assembly
using System.Drawing; // also requires a reference to this assembly
using System.Drawing.Imaging;
using System.Threading;
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void button1_Click(object sender, RoutedEventArgs e)
{
// Create a new thread for demonstration purposes.
Thread thread = new Thread(() =>
{
// Determine the size of the "virtual screen", which includes all monitors.
int screenLeft = SystemInformation.VirtualScreen.Left;
int screenTop = SystemInformation.VirtualScreen.Top;
int screenWidth = SystemInformation.VirtualScreen.Width;
int screenHeight = SystemInformation.VirtualScreen.Height;
// Create a bitmap of the appropriate size to receive the screenshot.
using (Bitmap bmp = new Bitmap(screenWidth, screenHeight))
{
// Draw the screenshot into our bitmap.
using (Graphics g = Graphics.FromImage(bmp))
{
g.CopyFromScreen(screenLeft, screenTop, 0, 0, bmp.Size);
}
// Do something with the Bitmap here, like save it to a file:
bmp.Save("G:\\TestImage.jpg", ImageFormat.Jpeg);
}
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
}
}
答案 1 :(得分：6)
我创建了一个小助手，因为我今天需要这个案例并尝试了许多不同的功能。与监视器的数量无关，您可以使用以下代码块将其作为文件保存到磁盘或存储到db中的二进制字段。
using System.ComponentModel;//This namespace is required for only Win32Exception. You can remove it if you are catching exceptions from another layer.
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
namespace Company.Core.Helpers.Win32 {
public static class ScreenShotHelper {
private static Bitmap CopyFromScreen(Rectangle bounds) {
try {
var image = new Bitmap(bounds.Width, bounds.Height);
using var graphics = Graphics.FromImage(image);
graphics.CopyFromScreen(Point.Empty, Point.Empty, bounds.Size);
return image;
}
catch(Win32Exception) {//When screen saver is active
return null;
}
}
public static Image Take(Rectangle bounds) {
return CopyFromScreen(bounds);
}
public static byte[] TakeAsByteArray(Rectangle bounds) {
using var image = CopyFromScreen(bounds);
using var ms = new MemoryStream();
image.Save(ms, ImageFormat.Png);
return ms.ToArray();
}
public static void TakeAndSave(string path, Rectangle bounds, ImageFormat imageFormat) {
using var image = CopyFromScreen(bounds);
image.Save(path, imageFormat);
}
}
}
var bounds = new Rectangle();
bounds = Screen.AllScreens.Aggregate(bounds, (current, screen)
=> Rectangle.Union(current, screen.Bounds));
_card.ScreenShot = Convert.ToBase64String(ScreenShotHelper.TakeAsByteArray(bounds));
var bounds = new Rectangle();
bounds = Screen.AllScreens.Aggregate(bounds, (current, screen)
=> Rectangle.Union(current, screen.Bounds));
ScreenShotHelper.TakeAndSave(@"d:\screenshot.png", bounds, ImageFormat.Png);