How to copy data to clipboard in C#

Question

How can I copy a string (e.g "hello") to the System Clipboard in C#, so next time I press CTRL+V I'll get "hello"?

Answer 1

There are two classes that lives in different assemblies and different namespaces.

• WinForms: use following namespace declaration, make sure Main is marked with [STAThread] attribute:

  using System.Windows.Forms;
  

• WPF: use following namespace declaration

  using System.Windows;
  

• console: add reference to System.Windows.Forms, use following namespace declaration, make sure Main is marked with [STAThread] attribute. Step-by-step guide in another answer

  using System.Windows.Forms;
  

To copy an exact string (literal in this case):

Clipboard.SetText("Hello, clipboard");

To copy the contents of a textbox either use TextBox.Copy() or get text first and then set clipboard value:

Clipboard.SetText(txtClipboard.Text);

See here for an example. Or... Official MSDN documentation or Here for WPF.

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Remarks:

• Clipboard is desktop UI concept, trying to set it in server side code like ASP.Net will only set value on the server and has no impact on what user can see in they browser. While linked answer lets one to run Clipboard access code server side with SetApartmentState it is unlikely what you want to achieve.

• If after following information in this question code still gets an exception see "Current thread must be set to single thread apartment (STA)" error in copy string to clipboard

• This question/answer covers regular .NET, for .NET Core see - .Net Core - copy to clipboard?

Answer 2

For console projects in a step-by-step fashion, you'll have to first add the System.Windows.Forms reference. The following steps work in Visual Studio Community 2013 with .NET 4.5:

1. In Solution Explorer, expand your console project.
2. Right-click References, then click Add Reference...
3. In the Assemblies group, under Framework, select System.Windows.Forms.
4. Click OK.

Then, add the following using statement in with the others at the top of your code:

using System.Windows.Forms;

Then, add either of the following Clipboard.SetText statements to your code:

Clipboard.SetText("hello");
// OR
Clipboard.SetText(helloString);

And lastly, add STAThreadAttribute to your Main method as follows, to avoid a System.Threading.ThreadStateException:

[STAThreadAttribute]
static void Main(string[] args)
{
  // ...
}

Answer 3

My Experience with this issue using WPF C# coping to clipboard and System.Threading.ThreadStateException is here with my code that worked correctly with all browsers:

Thread thread = new Thread(() => Clipboard.SetText("String to be copied to clipboard"));
thread.SetApartmentState(ApartmentState.STA); //Set the thread to STA
thread.Start(); 
thread.Join();

credits to this post here

But this works only on localhost, so don't try this on a server, as it's not going to work.

On server-side, I did it by using zeroclipboard. The only way, after a lot of research.

Answer 4

Clipboard.SetText("hello");

You'll need to use the System.Windows.Forms or System.Windows namespaces for that.

Answer 5

Clip.exe is an executable in Windows to set the clipboard. Note that this does not work for other operating systems other than Windows, which still sucks.

        /// <summary>
        /// Sets clipboard to value.
        /// </summary>
        /// <param name="value">String to set the clipboard to.</param>
        public static void SetClipboard(string value)
        {
            if (value == null)
                throw new ArgumentNullException("Attempt to set clipboard with null");

            Process clipboardExecutable = new Process(); 
            clipboardExecutable.StartInfo = new ProcessStartInfo // Creates the process
            {
                RedirectStandardInput = true,
                FileName = @"clip", 
            };
            clipboardExecutable.Start();

            clipboardExecutable.StandardInput.Write(value); // CLIP uses STDIN as input.
            // When we are done writing all the string, close it so clip doesn't wait and get stuck
            clipboardExecutable.StandardInput.Close(); 

            return;
        }

Answer 6

If you don't want to set the thread as STAThread, use Clipboard.SetDataObject(object sthhere):

Clipboard.SetDataObject("Yay! No more STA thread!");

Answer 7

This works on .net core, no need to reference System.Windows.Forms

using Windows.ApplicationModel.DataTransfer;

DataPackage package = new DataPackage();
package.SetText("text to copy");
Clipboard.SetContent(package);

It works cross-platform. On windows, you can press windows + V to view your clipboard history

Answer 8

On ASP.net web forms use in the @page AspCompat="true", add the system.windows.forms to you project. At your web.config add:

  <appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="false" />
  </appSettings>

Then you can use:

Clipboard.SetText(CreateDescription());

Answer 9

If you don't want too or cannot use System.Windows.Forms you can use the Windows native api: user32 and the clipboard functions GetClipboardData and SetClipboardDat (pinvoke)

A .NET 6 wrapper library can be found here https://github.com/MrM40/WitWinClipboard/tree/main

Answer 10

For the modern cross-platform .NET, you'll need to use the MAUI version. The short answer is await Clipboard.Default.SetTextAsync("This text was highlighted in the UI."); and Microsoft.Maui.Essentials.dll should be referenced. The long answer is covered in this article.