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How do I copy the contents of a String to the clipboard in C#? [duplicate]

Tags:

c#

.net

clipboard

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How do I copy text to clipboard?

Select the first item that you want to copy, and press CTRL+C. Continue copying items from the same or other files until you have collected all of the items that you want. The Office Clipboard can hold up to 24 items.

What is clipboard in C#?

The Clipboard class provides functionality to place data to and retrieve data from the clipboard. Storing and Retrieving Data. Clipboard has static methods to copy and paste data. The SetDataObject method is used to store data that is in object format to the clipboard.


You can use System.Windows.Forms.Clipboard.SetText(...).


System.Windows.Forms.Clipboard.SetText (Windows Forms) or System.Windows.Clipboard.SetText (WPF)


I wish calling SetText were that easy but there are quite a few gotchas that you have to deal with. You have to make sure that the thread you are calling it on is running in the STA. It can sometimes fail with an access denied error then work seconds later without problem - something to do with the COM timing issues in the clipboard. And if your application is accessed over Remote Desktop access to the clipboard is sketchy. We use a centralized method to handle all theses scenarios instead of calling SetText directly.

@Stecy: Here's our centralized code:

The StaHelper class simply executes some arbitrary code on a thread in the Single Thread Apartment (STA) - required by the clipboard.

abstract class StaHelper
{
    readonly ManualResetEvent _complete = new ManualResetEvent( false );    

    public void Go()
    {
        var thread = new Thread( new ThreadStart( DoWork ) )
        {
            IsBackground = true,
        }
        thread.SetApartmentState( ApartmentState.STA );
        thread.Start();
    }

    // Thread entry method
    private void DoWork()
    {
        try
        {
            _complete.Reset();
            Work();
        }
        catch( Exception ex )
        {
            if( DontRetryWorkOnFailed )
                throw;
            else
            {
                try
                {
                    Thread.Sleep( 1000 );
                    Work();
                }
                catch
                {
                    // ex from first exception
                    LogAndShowMessage( ex );
                }
            }
        }
        finally
        {
            _complete.Set();
        }
    }

    public bool DontRetryWorkOnFailed{ get; set; }

    // Implemented in base class to do actual work.
    protected abstract void Work();
}

Then we have a specific class for setting text on the clipboard. Creating a DataObject manually is required in some edge cases on some versions of Windows/.NET. I don't recall the exact scenarios now and it may not be required in .NET 3.5.

class SetClipboardHelper : StaHelper
{
    readonly string _format;
    readonly object _data;

    public SetClipboardHelper( string format, object data )
    {
        _format = format;
        _data = data;
    }

    protected override void Work()
    {
        var obj = new System.Windows.Forms.DataObject(
            _format,
            _data
        );

        Clipboard.SetDataObject( obj, true );
    }
}

Usage looks like this:

new SetClipboardHelper( DataFormats.Text, "See, I'm on the clipboard" ).Go();

WPF: System.Windows.Clipboard (PresentationCore.dll)

Winforms: System.Windows.Forms.Clipboard

Both have a static SetText method.