Do not work Focus changing

[Trick-or-Tricks]

Please answer me such question. I have two textboxes on a form and ten buttons with digits (as a simple calculator buttons). When i click on any digits it must appears in one textbox. When I set focus on another textbox and click the same button this digit must appears in the next text box. I have such code:

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
If TextBox1.Focus = True Then
TextBox1.Text &= "1"
TextBox2.Select()
Else
...
end sub
But when the program is working digit is appearing just in the first textbox or in both textboxes at the same time.
Thanks for Your help if you can.

[Shaggy Hiker]

When you click on a button, which control will then have focus?

Put a breakpoint on the first line inside the If statement, and see if it is EVER reached. I think you will find that it is not, which is the point behind my question. Showing what is in the Else part of that sub might further explain the behavior.

I believe that you're going to have to use something other than Focus to indicate which textbox should be written to. Focus can shift around to other controls, or even no control, so having a variable at form scope to indicate which control should be the target will ultimately be a more reliable solution.

[4x2y]

Declare a module level variable mActiveTextBox, when a TextBox got focus set mActiveTextBox to that TextBox, something like this

Option Strict On
Option Explicit On
 
Public Class Form1
    Private mActiveTextBox As TextBox
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click
        mActiveTextBox.Text &= "1"
    End Sub
 
    Private Sub TextBox1_GotFocus(sender As Object, e As EventArgs) Handles TextBox1.GotFocus
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub TextBox2_GotFocus(sender As Object, e As EventArgs) Handles TextBox2.GotFocus
        mActiveTextBox = TextBox2
    End Sub
 
End Class

[Trick-or-Tricks]

Thank you.
Well, my question wasn't so correct.
I need the next: when cursor is in the textbox1 and I click the button the digit is appearing in the textbox1, and when cursor is in the textbox2 and I click the button the digit is appearing in the textbox2. But now I have a such situation: I press the button and digits appears in both textboxes (or triple, when I add textbox3). The code is like this:
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
If TextBox1.Focus Then
TextBox1.Text &= "1"
End If
If TextBox2.Focus = True Then
TextBox2.Text &= "1"
End If
End Sub

[Trick-or-Tricks]

Declare a module level variable mActiveTextBox, when a TextBox got focus set mActiveTextBox to that TextBox, something like this

Option Strict On
Option Explicit On
 
Public Class Form1
    Private mActiveTextBox As TextBox
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click
        mActiveTextBox.Text &= "1"
    End Sub
 
    Private Sub TextBox1_GotFocus(sender As Object, e As EventArgs) Handles TextBox1.GotFocus
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub TextBox2_GotFocus(sender As Object, e As EventArgs) Handles TextBox2.GotFocus
        mActiveTextBox = TextBox2
    End Sub
 
End Class

Very-very thanks a lot Your method is working absolutely correctly. You're an Angel for me tonight. My problem is solved. Thank you again.

[jmcilhinney]

Declare a module level variable mActiveTextBox, when a TextBox got focus set mActiveTextBox to that TextBox, something like this

Option Strict On
Option Explicit On
 
Public Class Form1
    Private mActiveTextBox As TextBox
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click
        mActiveTextBox.Text &= "1"
    End Sub
 
    Private Sub TextBox1_GotFocus(sender As Object, e As EventArgs) Handles TextBox1.GotFocus
        mActiveTextBox = TextBox1
    End Sub
 
    Private Sub TextBox2_GotFocus(sender As Object, e As EventArgs) Handles TextBox2.GotFocus
        mActiveTextBox = TextBox2
    End Sub
 
End Class

As the documentation states, application developers should use the Enter and Leave events rather than the GotFocus and LostFocus events. Likewise, use the Select method rather than the Focus method.

[Shaggy Hiker]

I've never trusted the LostFocus event. Back in VB5/6, I found that it wasn't reliably raised. For that reason, I stopped using it and have never used it since. I'm not surprised that MS discourages use of those events.