How to copy data to clipboard in C#

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?

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)
{
  // ...
}

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.