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I have a TextBox component in C# WinForms.

When I Right-click on it, I would like to disable the paste option, whilst still allowing users to Cut and Copy.

I have investigated a few options, neither of which fully meet my requirements -

  1. If I use this option, it will prevent Cut and Copy along with Paste which I do not want.

    txt.ShortcutsEnabled = false;

  2. If I override the ContextMenu of TextBox, I will have to write the Cut and Copy Features myself in the new context menu.

    txt.ContextMenu = new ContextMenu(); // or some other

Are there any options I can use to disable only the Paste option of the default context menu, retaining Cut and Copy?

Thanos Markou
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Abdul Rehman Sayed
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  • Does [this answer](http://stackoverflow.com/a/5113773/2307070) help you ? – Thomas Ayoub Apr 29 '15 at 11:23
  • You only want to disable paste menu item during right click? or disable paste with keyboard shortcuts too – Kira Apr 29 '15 at 11:40
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    @Anand Only the Right Click.. – Abdul Rehman Sayed Apr 29 '15 at 11:41
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    @Thomas Those options do not help. I want to disable only the Paste Option in Right Click (without implementing cut/copy & other default Context Menu features myself). keyboard is managed.. – Abdul Rehman Sayed Apr 29 '15 at 12:22
  • If you want to preserve pasting via `Ctrl-V` why did you Reject an edit which clarified this in the question? Do you not wish to preserve pasting via `Ctrl-V`? – Eilidh Apr 29 '15 at 12:28
  • @Eilidh I just want to manage default context menu Paste via Right Clicking. Keyboard is already handled by me. Hence I rejected the edit. – Abdul Rehman Sayed Apr 29 '15 at 12:34
  • If you don't clarify what you are doing (or do / do not wish done) with keyboard shortcuts in the body of your question, Answers may address it (as they have done so already). – Eilidh Apr 29 '15 at 12:40

3 Answers3

3

Assuming the Paste menu item is always the fifth element in the textbox context menu (zero-based and a separator counts as item too), you could subclass the TextBox class (here: CustomMenuTextBox) and override the WndProc method to disable that specific menu item:

public static class User32
{
    [DllImport("user32.dll")]
    public static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);
}

public class CustomMenuTextBox : TextBox
{
    protected override void WndProc(ref Message m)
    {
        if (m.Msg == 0x0093 /*WM_UAHINITMENU*/ || m.Msg == 0x0117 /*WM_INITMENUPOPUP*/ || m.Msg == 0x0116 /*WM_INITMENU*/)
        {
            IntPtr menuHandle = m.Msg == 0x0093 ? Marshal.ReadIntPtr(m.LParam) : m.WParam;

            // MF_BYPOSITION and MF_GRAYED
            User32.EnableMenuItem(menuHandle, 4, 0x00000400 | 0x00000001);
        }

        base.WndProc(ref m);
    }
}

Based on Add item to the default TextBox context menu.

Community
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CodeCaster
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0

The following two steps disable the Copy/Paste feature in a textbox:

  • Disable the default menu and associate the textbox with an empty context menu that has no menu items (mouse actions).

  • The user can still use the shortcut keys on the keyboard and perform these operations. So, override the ProcessCmdKey method as shown below:

    // Constants
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);
    }
}

Note: Return true, which supresses the base class functionality.

OR You can use :

 ContextMenuStrip mnu = new ContextMenuStrip();
 ToolStripMenuItem mnuCopy = new ToolStripMenuItem("Copy");
 ToolStripMenuItem mnuCut = new ToolStripMenuItem("Cut");

 mnuCopy.Click += new EventHandler(mnuCopy_Click);
 mnuCut.Click += new EventHandler(mnuCut_Click);

 mnu.MenuItems.AddRange(new MenuItem[] { mnuCopy, mnuCut});
 txt.ContextMenu = mnu;

Note : You can't disable Past option in default context menu for that you have to add contextMenuStrip in your form.

 this.contextMenuStrip1.Items.AddRange(new 
 System.Windows.Forms.ToolStripItem[] {
        this.Undo,
        this.Cut,
        this.Copy,
        this.Paste,
        this.Delete,
        this.SelectAll});
 this.contextMenuStrip1.Opening += new System.ComponentModel.CancelEventHandler(this.contextMenuStrip1_Opening);

 this.txt.ContextMenuStrip = this.contextMenuStrip1;

Hope Useful for you link

Krunal Mevada
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  • This dos not retain the 'Cut' and 'Copy' functionality which the Abdul requires in his solution. – Eilidh Apr 29 '15 at 11:34
0

If you only need Cut Copy and Paste options, Maybe it is better create your custom contentMenuStrip, you can do that visually in Visual Studio and it is very easy to implement the copy cut and paste options. Then you can control in your program when you want to have any option enable or not.

For example this code in the Opening event of your custom ContentMenuStrip, disable copy and cut when you haven't selected text in a text-box, and only enable Paste if your clipboard contain text or images.

  private void contextSuperEditor_Opening(object sender, CancelEventArgs e)
        {
            if (tbText.SelectionLength > 0)
            {
                MenuCopy.Enabled = true;
                MenuCut.Enabled = true;
                MenuPaste.Enabled = false; 
            }
            else
            {
                MenuCopy.Enabled = false;
                MenuCut.Enabled = false;
                if (Clipboard.ContainsText() | Clipboard.ContainsImage())
                {
                    MenuPaste.Enabled = true;
                }
            }
        }
freedeveloper
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