How to determine which control on form has focus?

Question

I\'ve read elsewhere on here that to capture \"Enter\" key stroke in a text box and use it as if pushing a button I should set the KeyPreview property of the form to true an

Answer 1

You could use this code as a starting point to capture the key down events of the form. The ActiveControl is one that has the focus. In this example, it's flexible for adding other actions on "Enter" when you are in different TextBoxes on the form. It's VB.NET, but you should be able to easily convert to C#.

Private Sub MyForm_KeyDown(ByVal sender As Object, _
    ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown

    If e.KeyCode = Keys.Enter Then
        If Me.ActiveControl.Name = Me.TextBox1.Name Then
            ' This is the TextBox we want to be active to run filterByDeviceSN()
            filterByDeviceSN()
        ElseIf Me.ActiveControl.Name = Me.TextBox2.Name Then
            foo()
        End If
    End If
End Sub