.Net Core - 复制到剪贴板？

Is it possible to copy something to the clipboard using .Net Core (in a platform-agnostic way)?

看来Clipboard https://msdn.microsoft.com/en-us/library/system.windows.clipboard(v=vs.110).aspx缺少类，并且 P/Invoking 不是 Windows 之外的选项。

_{Edit: Unfortunately until now there's been a discrepancy between what my question said and what people heard when they read the question. Based on the comments and answers two things are clear. First, very few care whether the truest kind of "ivory tower" platform agnosticism exists or not. Second, when people post code examples showing how you use the clipboard on different platforms then the technically correct answer ("no, it's not possible https://stackoverflow.com/a/49459767/3063273") is confusing. So I have struck the parenthetical clause.}

我的这个项目（https://github.com/SimonCropp/TextCopy https://github.com/SimonCropp/TextCopy）使用 PInvoke 和命令行调用的混合方法。目前它支持

• 装有 .NET Framework 4.6.1 及更高版本的 Windows
• 带有 .NET Core 2.0 及更高版本的 Windows
• 装有 Mono 5.0 及更高版本的 Windows
• 带有 .NET Core 2.0 及更高版本的 OSX
• OSX 与 Mono 5.20.1 及更高版本
• 带有 .NET Core 2.0 及更高版本的 Linux
• 采用 Mono 5.20.1 及更高版本的 Linux

Usage:

Install-Package TextCopy

TextCopy.ClipboardService.SetText("Text to place in clipboard");

或者直接使用实际的代码

Windows

https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/WindowsClipboard.cs https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/WindowsClipboard.cs

static class WindowsClipboard
{
    public static void SetText(string text)
    {
        OpenClipboard();

        EmptyClipboard();
        IntPtr hGlobal = default;
        try
        {
            var bytes = (text.Length + 1) * 2;
            hGlobal = Marshal.AllocHGlobal(bytes);

            if (hGlobal == default)
            {
                ThrowWin32();
            }

            var target = GlobalLock(hGlobal);

            if (target == default)
            {
                ThrowWin32();
            }

            try
            {
                Marshal.Copy(text.ToCharArray(), 0, target, text.Length);
            }
            finally
            {
                GlobalUnlock(target);
            }

            if (SetClipboardData(cfUnicodeText, hGlobal) == default)
            {
                ThrowWin32();
            }

            hGlobal = default;
        }
        finally
        {
            if (hGlobal != default)
            {
                Marshal.FreeHGlobal(hGlobal);
            }

            CloseClipboard();
        }
    }

    public static void OpenClipboard()
    {
        var num = 10;
        while (true)
        {
            if (OpenClipboard(default))
            {
                break;
            }

            if (--num == 0)
            {
                ThrowWin32();
            }

            Thread.Sleep(100);
        }
    }

    const uint cfUnicodeText = 13;

    static void ThrowWin32()
    {
        throw new Win32Exception(Marshal.GetLastWin32Error());
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern IntPtr GlobalLock(IntPtr hMem);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool GlobalUnlock(IntPtr hMem);

    [DllImport("user32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool OpenClipboard(IntPtr hWndNewOwner);

    [DllImport("user32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool CloseClipboard();

    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr SetClipboardData(uint uFormat, IntPtr data);

    [DllImport("user32.dll")]
    static extern bool EmptyClipboard();
}

macOS

https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/OsxClipboard.cs https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/OsxClipboard.cs

static class OsxClipboard
{
    public static void SetText(string text)
    {
        var nsString = objc_getClass("NSString");
        IntPtr str = default;
        IntPtr dataType = default;
        try
        {
            str = objc_msgSend(objc_msgSend(nsString, sel_registerName("alloc")), sel_registerName("initWithUTF8String:"), text);
            dataType = objc_msgSend(objc_msgSend(nsString, sel_registerName("alloc")), sel_registerName("initWithUTF8String:"), NSPasteboardTypeString);

            var nsPasteboard = objc_getClass("NSPasteboard");
            var generalPasteboard = objc_msgSend(nsPasteboard, sel_registerName("generalPasteboard"));

            objc_msgSend(generalPasteboard, sel_registerName("clearContents"));
            objc_msgSend(generalPasteboard, sel_registerName("setString:forType:"), str, dataType);
        }
        finally
        {
            if (str != default)
            {
                objc_msgSend(str, sel_registerName("release"));
            }

            if (dataType != default)
            {
                objc_msgSend(dataType, sel_registerName("release"));
            }
        }
    }

    [DllImport("/System/Library/Frameworks/AppKit.framework/AppKit")]
    static extern IntPtr objc_getClass(string className);

    [DllImport("/System/Library/Frameworks/AppKit.framework/AppKit")]
    static extern IntPtr objc_msgSend(IntPtr receiver, IntPtr selector);

    [DllImport("/System/Library/Frameworks/AppKit.framework/AppKit")]
    static extern IntPtr objc_msgSend(IntPtr receiver, IntPtr selector, string arg1);

    [DllImport("/System/Library/Frameworks/AppKit.framework/AppKit")]
    static extern IntPtr objc_msgSend(IntPtr receiver, IntPtr selector, IntPtr arg1, IntPtr arg2);

    [DllImport("/System/Library/Frameworks/AppKit.framework/AppKit")]
    static extern IntPtr sel_registerName(string selectorName);

    const string NSPasteboardTypeString = "public.utf8-plain-text";
}

Linux

https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/LinuxClipboard_2.1.cs https://github.com/CopyText/TextCopy/blob/master/src/TextCopy/LinuxClipboard_2.1.cs

static class LinuxClipboard
{
    public static void SetText(string text)
    {
        var tempFileName = Path.GetTempFileName();
        File.WriteAllText(tempFileName, text);
        try
        {
            BashRunner.Run($"cat {tempFileName} | xclip");
        }
        finally
        {
            File.Delete(tempFileName);
        }
    }

    public static string GetText()
    {
        var tempFileName = Path.GetTempFileName();
        try
        {
            BashRunner.Run($"xclip -o > {tempFileName}");
            return File.ReadAllText(tempFileName);
        }
        finally
        {
            File.Delete(tempFileName);
        }
    }
}

static class BashRunner
{
    public static string Run(string commandLine)
    {
        var errorBuilder = new StringBuilder();
        var outputBuilder = new StringBuilder();
        var arguments = $"-c \"{commandLine}\"";
        using (var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "bash",
                Arguments = arguments,
                RedirectStandardOutput = true,
                RedirectStandardError = true,
                UseShellExecute = false,
                CreateNoWindow = false,
            }
        })
        {
            process.Start();
            process.OutputDataReceived += (sender, args) => { outputBuilder.AppendLine(args.Data); };
            process.BeginOutputReadLine();
            process.ErrorDataReceived += (sender, args) => { errorBuilder.AppendLine(args.Data); };
            process.BeginErrorReadLine();
            if (!process.WaitForExit(500))
            {
                var timeoutError = $@"Process timed out. Command line: bash {arguments}.
Output: {outputBuilder}
Error: {errorBuilder}";
                throw new Exception(timeoutError);
            }
            if (process.ExitCode == 0)
            {
                return outputBuilder.ToString();
            }

            var error = $@"Could not execute process. Command line: bash {arguments}.
Output: {outputBuilder}
Error: {errorBuilder}";
            throw new Exception(error);
        }
    }
}