How do you detect simultaneous keypresses such as "Ctrl + T" in VB.NET?

vb.net keydown
J2Tuner picture J2Tuner · Dec 10, 2012 · Viewed 43.8k times · Source

I am trying to detect the keys "Control" and "t" being pressed simultaneously in VB.NET. The code I have so far is as follows:

Private Sub frmTimingP2P_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
    If e.KeyValue = Keys.ControlKey And e.KeyValue = Keys.T Then
        MessageBox.Show("Ctrl + T")
    End If
End Sub

I can detect one key or the other by removing the and statement and the second keyvalue statement, but I don't really get anything when I try this. Is there another method?

Thanks

Answer

Konrad Rudolph picture Konrad Rudolph · Dec 10, 2012

First of all, And in your code should be AndAlso since it’s a logical operator. And in VB is a bit operator. Next, you can use the Modifiers property to test for modifier keys:

If (e.KeyCode And Not Keys.Modifiers) = Keys.T AndAlso e.Modifiers = Keys.Ctrl Then
    MessageBox.Show("Ctrl + T")
End If

The e.KeyCode And Not Keys.Modifiers in the first part of the condition is necessary to mask out the modifier key.

If e.Modifiers = Keys.Ctrl can also be written as If e.Control.

Alternatively, we can collate these two queries by asking directly whether the combination Ctrl+T was pressed:

If e.KeyCode = (Keys.T Or Keys.Ctrl) Then …

In both snippets we make use of bit masks.

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