Can anybody please suggest how to handle Cut,Copy and Paste events on a Text Box in WinForms using C#?
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1TextBox already handles this itself, why do you want to help?Hans Passant– Hans Passant2011-02-25 04:47:26 +00:00Commented Feb 25, 2011 at 4:47
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@Sharp: be clear. Do you want to disable those features, or handle them yourself?p.campbell– p.campbell2011-02-25 05:05:14 +00:00Commented Feb 25, 2011 at 5:05
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2Make your textbox property readonly to true...Crimsonland– Crimsonland2011-02-25 05:51:29 +00:00Commented Feb 25, 2011 at 5:51
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@p.Campbell: First of all thanks a lot for your comments on my question and sorry for late response but I clearly mentioned in the title that I want to disable all the Cut,Copy and Paste functionality in my Win Form TextBox.SharpUrBrain– SharpUrBrain2011-02-25 10:30:15 +00:00Commented Feb 25, 2011 at 10:30
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@Crimsonland: If I am making my textbox.readonly=true then I can not edit it again and I want it as an editable textbox. Thanks for your commentSharpUrBrain– SharpUrBrain2011-02-25 10:33:41 +00:00Commented Feb 25, 2011 at 10:33
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6 Answers
In WinForms, the easiest way to disable cut, copy and paste features on a textbox is to set the ShortcutsEnabled property to false.
You'd have to subclass the textbox and then override the WndProc method to intercept the windows messages before the control does.
Here's an example that illustrates a TextBox that intercepts the WM_PASTE message.
And for reference, here's the definition of the message constants:
You'd simply ignore the inbound message, like so:
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_PASTE || m.Msg == WM_COPY || m.Msg == WM_CUT)
{
// ignore input if it was from a keyboard shortcut
// or a Menu command
}
else
{
// handle the windows message normally
base.WndProc(ref m);
}
}
1 Comment
mike
This was the solution for me. It is especially a useful approach when needed for a textbox to enter a password: in that case you would want to allow WM_PASTE, but not the others.
Suppose you have a TextBox named textbox1. It sounds like you want to disable the cut, copy and paste functionality of a TextBox.
Try this quick and dirty proof of concept snippet:
private void Form1_Load(object sender, EventArgs e)
{
ContextMenu _blankContextMenu = new ContextMenu();
textBox1.ContextMenu = _blankContextMenu;
}
private const Keys CopyKeys = Keys.Control | Keys.C;
private const Keys PasteKeys = Keys.Control | Keys.V;
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if ((keyData == CopyKeys) || (keyData == PasteKeys))
{
return true;
}
else
{
return base.ProcessCmdKey(ref msg, keyData);
}
}
2 Comments
Cody Gray
Why would you suggest handling this at the form level, rather than subclassing the
TextBox control itself?
p.campbell
@Cody: it's a simple demo. The question contained absolutely no info on the scale of the feature, the app, the use-cases, etc. So questions around 'why strategy X and not strategy Y' are tough to ask and answer when no real info is given by the questioner.
To prevent users to copy/paste using the keyboard set ShortcutsEnabled property to false. To prevent users to copy/paste from the context menu set ContextMenu property to new ContextMenu().
if (copyPasteEnabled) {
textBox1.ShortcutsEnabled = true;
textBox1.ContextMenu = null;
} else {
textBox1.ShortcutsEnabled = false;
textBox1.ContextMenu = new ContextMenu();
}
Comments
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
e.SuppressKeyPress = true;
}
if (e.Control == true)
{
switch (e.KeyCode)
{
case Keys.C:
case Keys.P:
case Keys.X:
e.Handled = true;
textBox1.SelectionLength = 0;
break;
}
}
}
private void textBox1_Enter(object sender, EventArgs e)
{
System.Windows.Forms.Clipboard.Clear();
}
1 Comment
Igor Levicki
This answer is terrible because program must never clear clipboard or put content on it without user interaction.
int cusorposition = m_TextBox1.SelectionStart;
if (TextBox1.Text[0] == ' ')
{
//Trim Spaces at beginning.
m_TextBox1.Text = m_TextBox1.Text.TrimStart(' ');
m_TextBox1.Text = m_TextBox1.Text.TrimEnd(' ');
m_TextBox1.SelectionStart = cusorposition ;
}
Hi I found a way how to get the current cursor position instead of handling cut, copy and Paste event in a text box named TextBox1.Here in the above I am keeping the backup of current Cursor Position and after trimming the extra spaces from the starting and from end position I am reassigning the current cursor position.
Thanks to all who helped me to fix this problem.