Disable default shortcuts on a TabControl

Question

Ctrl + PageUp/PageDown and Ctrl + Tab are default shortcuts for the TabControl. They help in moving between adjacent tabs. I would like Ctrl + PageX behaviour to work only for the outer tabs (tab1, tab2) and Ctrl + Tab behaviour for the inner tabs (tab3, tab4) when my focus is in the control (textbox here). For this, I need to disable the default behaviour. Is there some way to do this?

I looked at ProcessDialogKey and IsInputKey, but they seem to work only with single keydata. Modifiers are not handled.

Answer 1

TabControl has unusual keyboard shortcut processing, they are reflected to the OnKeyDown() method. This was done to avoid it disturbing the keyboard handling for the controls on a tab page.

You'll have to override the method. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto your Form.

using System;
using System.Windows.Forms;

class MyTabControl : TabControl {
  protected override void OnKeyDown(KeyEventArgs e) {
    if (e.KeyData == (Keys.Tab | Keys.Control) ||
        e.KeyData == (Keys.PageDown | Keys.Control)) {
      // Don't allow tabbing beyond last page
      if (this.SelectedIndex == this.TabCount - 1) return;
    }
    base.OnKeyDown(e);
  }
}

Answer 2

As written, Hans Passant's answer didn't work unless you were on the last page of the tab control. I want something the doesn't allow the shortcuts on any of the tabs. The code below also incorporates AZ's additional logic to handle Ctrl + PageUp and Ctrl + PageDown. Hopefully this version makes the overall logic a little more clear:

using System.Windows.Forms;

namespace MyNameSpace
{
    internal class NoTabTabControl : TabControl
    {
        /// <summary>
        /// Intercept any key combinations that would change the active tab.
        /// </summary>
        protected override void OnKeyDown(KeyEventArgs e)
        {
            bool changeTabKeyCombination =
                (e.Control
                    && (e.KeyCode == Keys.Tab
                        || e.KeyCode == Keys.Next
                        || e.KeyCode == Keys.Prior));

            if (!changeTabKeyCombination)
            {
                base.OnKeyDown(e);
            }
        }
    }
}