Question

I have multiple textbox in a form. How do I know what textbox the cursor currently is?
Trying to do something like this:

If TextBox2.Focus() = True Then
            MessageBox.Show("its in two")
        ElseIf TextBox3.Focus = True Then
            MessageBox.Show("its in three")
        End If

But I think its not working.

Answer 1

Obviously, it will not work if you are calling your code in a Button_Click because when you click the Button then the focus is itself goes to the Button which you have clicked.

You can do two things:

Make a combined Focus event for all TextBoxes and check its Sender object.

Private Sub TextBox_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.Enter, TextBox3.Enter
    Dim currTextBox As TextBox = sender

    If currTextBox.Equals(TextBox2) Then
        MessageBox.Show("it's in two")
    ElseIf currTextBox.Equals(TextBox3) Then
        MessageBox.Show("it's in three")
    End If

End Sub

OR

Take a global string variable, and set its value at each TextBox_Focus event, then check string value in the button click event.

 Dim str As String  
 Private Sub TextBox2_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs)  Handles TextBox2.Enter
     str = "two"
 End Sub

 Private Sub TextBox3_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs)  Handles TextBox3.Enter
     str = "three"
 End Sub

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)  Handles Button1.Click
      MessageBox.Show("it's in " & str)
 End Sub