Question

I have a situation with a usercontrol which contains only one textbox and which is substantially different from the behavior in VB6.
Necessity is that in certain circumstances to cancel key.Down of usercontrol mentioned that it does not fire this event (in an external program).
There I tried to put to _KeyDown event handler of textbox in usercontrol e.handled = true and e.suppressKeyPress = true but with no results.
Usercontrol still emits KeyDown event with a keystroke.

Private Sub myText_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles myText.KeyDown

If e.KeyCode = Keys.Down Then 
    If stop_Down Then    'property
        e.Handled = True
        e.SuppressKeyPress = True
        Exit Sub
    End If
End If

Program passes through this code properly regarding of properties.
But don’t suppress _KeyDown event for usercontrol.

How to suppress _KeyDown event to be fired from usercontrol in situation showed in upper code?

Answer 1

You can override the ProcessCmdKey function. This is the first function in a chain that receives key strokes.

Return true and the rest of the chain will not receive the stroke.

For example (for the user control):

Protected Overrides Function ProcessCmdKey(ByRef msg As Forms.Message, _
                                           keyData As Forms.Keys) As Boolean

    If MyCriteriasToIgnoreStroke Then
        Return True
    End If

    Return MyBase.ProcessCmdKey(msg, keyData)

End function