[RESOLVED] Disabling Home.End keys on TrackBar control

I have a TrackBar control that is part of a custom control. It functions fine, except I need to disable keyboard control of the TrackBar, i.e. the user should be able to drag the value of the trackbar with the mouse but not set it with the Home, End, or arrow keys. The reason for this is that the custom control is intended to be placed into a scrollable list. In other words, there can be 15 - 50 (or even more) of these controls in a single scroll list, and I want the Home, End, and arrow keys to ONLY control focus in the list.

What I have now works, so long as the user doesn't have focus on the TrackBar. When he does, then focus still shifts, but only after the value of the TrackBar on the currently selected control is adjusted.

In order to implement the focus change, I'm trapping the KeyUp event on the custom control and every sub-control on it. When any of those keys are pressed, I set e.Handled and e.SuppressKeyPress to true, but it isn't stopping the TrackBar from processing the keystroke to adjust the value.

Any ideas on how I can disable the TrackBar from processing these keystroke commands to alter the value?

I'm using .NET 4.0 under Windows 7.

Does this work?, maybe you already do this;

Code:

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    Private Sub TrackBar1_KeyDown(sender As System.Object, e As System.Windows.Forms.KeyEventArgs) _
        Handles TrackBar1.KeyDown
        e.Handled = True
    End Sub

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As far as you are using many TrackBar control then you have to create custom TrackBar and implement OnKeyDown event to set SuppressKeyPress = True when Home, End and arrows keys pressed.

* Add new class, name it MyTrackBar (or what you like)
* Paste the following code
* Build your project

A new control will added to the ToolBox, use it instead of the built-in TrackBar.

Code:

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Option Strict On
Option Explicit On

Public Class MyTrackBar
    Inherits Windows.Forms.TrackBar

    Protected Overrides Sub OnKeyDown(e As KeyEventArgs)
        Select Case e.KeyCode
            Case Keys.Home, Keys.End, Keys.Left, Keys.Right, Keys.Up, Keys.Down
                e.SuppressKeyPress = True

                MyBase.OnKeyDown(e) ' Comment this line if you want to unfire KeyDown event when those keys pressed.
            Case Else
                MyBase.OnKeyDown(e)
        End Select

    End Sub
End Class

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Okay, I solved the issue.

I kept what I have with the KeyUp event handler, but then I declared a KeyDown handler and set e.Handled = true and e.SuppressKeyPress = true for each of the specified keys. I suppose I had to suppress the keys at the first event to fire, KeyDown, even though I only want to process the KeyUp event for those keys.

So thanks for the suggestions... it works now.

2HongKongCV

You said

Quote:

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there can be 15 - 50 (or even more) of these controls in a single scroll list,

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Handling KeyDown event for 15~50 controls is really tough, creating a custom TrackBar as discribed above will save your time.