C#

Form2 f2 = new Form2();
			
f2.Show();

//shift the focus to the main form
this.Focus();

IDataObject oldData = Clipboard.GetDataObject();
// Construct your new DataObject and set it, then later...
Clipboard.SetDataObject();

IDataObject oldData = Clipboard.GetDataObject();
System.Windows.Forms.DataObject prevDat = new DataObject();

prevDat.SetData(oldData);

//
//.....
//...code for pasting operation here
//.........
//

 Clipboard.SetDataObject(prevDat,true);

IDataObject oldData = Clipboard.GetDataObject();
// Make your own DataObject. DO NOT TOUCH oldData
Clipboard.SetDataObject(oldData);

private void PasteImg(RichTextBox richTextBox1, string imageFileName)
{
	//Copy the previous clipped data
	IDataObject oldData = Clipboard.GetDataObject();



	#region Pasting the image
	if("" == imageFileName) imageFileName = @"c:\JayShared\music.bmp";


	Bitmap myBitmap = new Bitmap(imageFileName);

	// Copy the bitmap to the clipboard.
	Clipboard.SetDataObject(myBitmap, false);

	// Get the format for the object type.
	DataFormats.Format myFormat = DataFormats.GetFormat (DataFormats.Bitmap);

	// After verifying that the data can be pasted, paste
	if(richTextBox1.CanPaste(myFormat)) 
	{
		richTextBox1.Paste();
	}


	#endregion Pasting the image

	//
	//paste back the previous clipped data to the clipboard

	Clipboard.SetDataObject(oldData); //.......... Error occurs here.........


	//
}

IDataObject prevDat = Clipboard.GetDataObject();