How can you strip all formatting from a formatted text copied to the clipboard and paste it as plain text on the rich textbox?

1. How To:
Paste the Contents of the Clipboard as
Plain Text in a .NET RichTextBox
© DanieldotNET DEC2013
How to programmatically paste text in plain text format into a RichTextBox control.
Software Version: Visual Basic 2008 Express Edition, .NET 3.5
Contents
Introduction
DataFormats Class and DataFormats.Format Class
Building the Demo Application
Coding the Demo
Running the Demo Application
Introduction
Pasting text from the clipboard is a common operation in word processing. It
is also possible to paste richly formatted text from the clipboard into a
RichTextBox control. This is the default behavior: just press Ctrl+V and the
richly formatted text is on the RichTextBox.
However, there are applications that need the RichTextBox to accept
unformatted text only. For example when creating a Notepad application, one
might want to restrict the contents to plain text. This short article is about
how it can be done programmatically.
DataFormats Class and DataFormats.Format Class
The RichTextBox Class comes with two methods for pasting data from the
Clipboard into the control: the Paste() method and the
Paste(DataFormats.Format) method. The Paste() method simply pastes
data from the Clipboard in whichever format the data is. On the other hand,
Paste(DataFormats.Format) pastes data from the Clipboard only if it is in
the format specified by the DataFormats.Format object passed into the
method.

2. A DataFormats.Format object stores the name and id of a specific Clipboard
format. Passing this information into the Paste method causes it to paste the
Clipboard data if the clipboard data is in the specified format. However, it is
possible to first find out if the Clipboard data is in the specified format by
calling the RichTextBox.CanPaste method. CanPaste also requires a
DataFormats.Format argument and returns True if the Clipboard data is in
the specified format.
To solve the problem of knowing the specific names and ids of the common
data formats – for example bitmap, text, Unicode text, rich text, html – the
DataFormats class provides static, predefined members representing the
common data formats. In order to construct a DataFormats.Format object,
however, the name of the required data format (one of the membwers of the
DataFormats class) can be passed into the DataFormats.GetFormat method.
This method will use the entered information to construct the required object
which can then be used by the CanPaste and Paste methods of the
RichTextBox object.
Building the Demo Application
This Demo Application allows the user to paste the contents of the Clipboard on a
RichTextBox control in Plain Text Format only.
1. Create a New Windows Application named CutCopyPasteDemo
2. Put three buttons and a RichTextBox control on Form1. Change the
properties of each control as follows:
Button1 Text = Cut
Button2 Text = Copy
Button3 Text = Paste
RichTextBox1 ShortCutsEnabled = False
Form1 Text = Cut Copy Paste Demo
Note
If the ShortCutsEnabled property is set to True, it allows the shortcut key
combination Ctrl+V (for paste) to be active on the RichTextBox. When
Ctrl+V is pressed during runtime, it pastes any content from the clipboard,
including rich text and pictures. So to control this behavior, set the property
to False.
Your interface should resemble the one below.

3. Coding the Demo
3. Go to the Code Window and make your code look like the following
Visual Basic
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles Button1.Click
' Ensures that text is currently selected in RichTextBox1
' before moving the selected text to the Clipboard
If RichTextBox1.SelectionLength > 0 Then
' Move the selected text to the Clipboard
RichTextBox1.Cut()
End If
End Sub

4. Private Sub Button2_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles Button2.Click
' Ensures that text is currently selected in RichTextBox1
' before moving the selected text to the Clipboard
If RichTextBox1.SelectionLength > 0 Then
' Copy the selected text to the Clipboard
RichTextBox1.Copy()
End If
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles Button3.Click
' Define a PlainText data format
Dim PlainTextFormat As DataFormats.Format = _
DataFormats.GetFormat(DataFormats.Text)
' First verify that the data in the Clipboard is plaintext
' format before pasting
If RichTextBox1.CanPaste(PlainTextFormat) Then
' Paste the contents of the Clipboard to RichTextBox1
RichTextBox1.Paste(PlainTextFormat)
End If
End Sub
The code above has three event handling methods
a. Button1_Click contains logic for moving text to the clipboard. Notice that
the Cut method of the RichTextBox is wrapped with an if-statement. This is
because nothing will be moved to the clipboard if no text is selected. To find
out if text is selected in the RichTextBox, the if statement checks the
SelectionLength property of the RichTextBox, which will be zero if no text is
selected.
b. Button2_Click contains logic for copying text to the clipboard. Notice the
similarity between Button1_Click and Button2_Click. If no text is selected,
nothing will be copied to the clipboard.
c. Button3_Click contains the pasting logic. The DataFormats.Format variable
plainTextFormat stores the text data format

5. Visual Basic
Dim PlainTextFormat As DataFormats.Format = _
DataFormats.GetFormat(DataFormats.Text)
The contents of the plainTextFormat variable is then passed to the Paste
method
Visual Basic
RichTextBox1.Paste(PlainTextFormat)
Running the Demo
Just press the F5 key to test your Demo. Go to the Code Window and copy the
source code from there. The source code is formatted text. Now try to paste the
contents of the clipboard using the paste button. The output below shows that the
text that was copied to the clipboard is pasted to the RichTextBox unformatted.