当我们需要在 Linux 和 OS X 上在同一个软件中使用 Mono 截屏时，我们遇到了同样的问题。
实际上，您可以在 Linux 上的 Mono 上使用 CopyFromScreen。但是，您需要安装单完整包，其中包括 System.Drawing。
对于OS X，最可靠的方法是处理。启动screencapture 命令行工具。它默认存在。
对于 Linux，为了使其可靠，可以使用 ImageMagic 中的 import 命令行（在这种情况下，您需要使其成为依赖项），或强制依赖于 @987654325 @ 包含 System.Drawing 的包。根据我们的测试，Gtk# 方法不可靠，可能会提供空白屏幕或异常失败（我们每天在各种机器上截取数千张屏幕截图）。
另一件事是，当您需要在一个屏幕截图中捕获多个显示时，您必须在通过 CopyFromScreen 分别拍摄后正确对齐单独的屏幕截图。
所以到目前为止我们有这个解决方案：
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Windows.Forms;
namespace Pranas
{
/// <summary>
/// ScreenshotCapture
/// </summary>
public static class ScreenshotCapture
{
#region Public static methods
/// <summary>
/// Capture screenshot to Image object
/// </summary>
/// <param name="onlyPrimaryScreen">Create screen only from primary screen</param>
/// <returns></returns>
public static Image TakeScreenshot(bool onlyPrimaryScreen = false)
{
try
{
return WindowsCapture(onlyPrimaryScreen);
}
catch (Exception)
{
return OsXCapture(onlyPrimaryScreen);
}
}
#endregion
#region Private static methods
//private static Image ImageMagicCapture(bool onlyPrimaryScreen)
//{
// return ExecuteCaptureProcess("import", "-window root ");
//}
private static Image OsXCapture(bool onlyPrimaryScreen)
{
var data = ExecuteCaptureProcess(
"screencapture",
string.Format("{0} -T0 -tpng -S -x", onlyPrimaryScreen ? "-m" : ""));
return data;
}
/// <summary>
/// Start execute process with parameters
/// </summary>
/// <param name="execModule">Application name</param>
/// <param name="parameters">Command line parameters</param>
/// <returns>Bytes for destination image</returns>
private static Image ExecuteCaptureProcess(string execModule, string parameters)
{
var imageFileName = Path.Combine(Path.GetTempPath(), string.Format("screenshot_{0}.jpg", Guid.NewGuid()));
var process = Process.Start(execModule, string.Format("{0} {1}", parameters, imageFileName));
if (process == null)
{
throw new InvalidOperationException(string.Format("Executable of '{0}' was not found", execModule));
}
process.WaitForExit();
if (!File.Exists(imageFileName))
{
throw new InvalidOperationException(string.Format("Failed to capture screenshot using {0}", execModule));
}
try
{
return Image.FromFile(imageFileName);
}
finally
{
File.Delete(imageFileName);
}
}
/// <summary>
/// Capture screenshot with .NET standard implementation
/// </summary>
/// <param name="onlyPrimaryScreen"></param>
/// <returns>Return bytes of screenshot image</returns>
private static Image WindowsCapture(bool onlyPrimaryScreen)
{
if (onlyPrimaryScreen) return ScreenCapture(Screen.PrimaryScreen);
var bitmaps = (Screen.AllScreens.OrderBy(s => s.Bounds.Left).Select(ScreenCapture)).ToArray();
return CombineBitmap(bitmaps);
}
/// <summary>
/// Create screenshot of single display
/// </summary>
/// <param name="screen"></param>
/// <returns></returns>
private static Bitmap ScreenCapture(Screen screen)
{
var bitmap = new Bitmap(screen.Bounds.Width, screen.Bounds.Height, PixelFormat.Format32bppArgb);
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.CopyFromScreen(
screen.Bounds.X,
screen.Bounds.Y,
0,
0,
screen.Bounds.Size,
CopyPixelOperation.SourceCopy);
}
return bitmap;
}
/// <summary>
/// Combine images into one bitmap
/// </summary>
/// <param name="images"></param>
/// <returns>Combined image</returns>
private static Image CombineBitmap(ICollection<Image> images)
{
Image finalImage = null;
try
{
var width = 0;
var height = 0;
foreach (var image in images)
{
width += image.Width;
height = image.Height > height ? image.Height : height;
}
finalImage = new Bitmap(width, height);
using (var g = Graphics.FromImage(finalImage))
{
g.Clear(Color.Black);
var offset = 0;
foreach (var image in images)
{
g.DrawImage(image,
new Rectangle(offset, 0, image.Width, image.Height));
offset += image.Width;
}
}
}
catch (Exception ex)
{
if (finalImage != null)
finalImage.Dispose();
throw ex;
}
finally
{
//clean up memory
foreach (var image in images)
{
image.Dispose();
}
}
return finalImage;
}
#endregion
}
}
或通过 NuGet 安装（免责声明：我是作者）：
PM> Install-Package Pranas.ScreenshotCapture
我们在产品的许多设置中大量使用它，因此我们会定期改进代码并将注释放入blog。