Question

I have 2 questions. first i wanna do something like these following codes that prevent (CTRL + C ) in a textbox but it won’t work. it won’t show anything in the messagebox.

The second question is how i can do something when the user pressed ( CTRL + C ) nothing will save in clipboard or automatically delete the value after pressing ( CTRL + C )

Here is the code :

 private void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.C && e.KeyCode == Keys.LControlKey)
        {
            MessageBox.Show("NOT ALLOWED");
        }

    }

Answer 1

You’re comparing the KeyCode for equality against two different values, and it’ll never be both. I think you meant to check for Control:

if(e.KeyCode == Keys.C && e.Control) {
    MessageBox.Show("NOT ALLOWED");
}

As for stopping the copy operation, it should be as easy as:

e.SuppressKeyPress = true;

And you can always clear the clipboard using:

Clipboard.Clear();