Why is Focus Rectangle not shown until Tab key pressed?

Question

I have a weird problem (probably only to understand) why in a test app the focus rect is not shown until i press the tab key.

I want to show a dialog with two radioboxes and two buttons. When i display the dialog, i'd like to see a focus rect around my first radiobutton. (So that the user can see where the focus is.) I ordered the controls and set the tabindex property from 0 to 4 so that they are in the correct order. (radiobox 1 has tabindex 0, ...)

When i show the dialog the first radiobox has the focus, but it has no focus rect around it. (Until i press tab key.)

I created an completely empty winforms project (Visual Studio 2010), added the controls and started it. So there is nothing special at all.

Can someone give me a hint what i am doing wrong?

Sorry, here is the code of my sample:

Public Class Form1

Private Sub Button1_Click(sender As System.Object, _
  e As System.EventArgs) _
    Handles Button1.Click

    Me.Close()
End Sub

Private Sub Button2_Click(sender As System.Object, _
  e As System.EventArgs) _
    Handles Button2.Click

    Me.Close()
End Sub

Private Sub Form1_Shown(sender As Object, _
   e As System.EventArgs) _
  Handles Me.Shown

    RadioButton1.Focus()
    RadioButton1.Select()
    SendKeys.SendWait("{TAB}")
    SendKeys.SendWait("+{TAB}")

End Sub

End Class

Answer 1

As I commented, this is really a user preference setting.

But to show the rectangle, try inheriting your own RadioButton and override the ShowFocusCues function:

Public Class RadioWithFocus
  Inherits RadioButton

  Protected Overrides ReadOnly Property ShowFocusCues() As Boolean
    Get
      Return True
    End Get
  End Property

End Class

Answer 2

Use the inherited Control.Focus() in the initialization method of your form, or wherever applicable. Something like:

public Form1 () {
    //Other stuff here
    radiobox1.Focus();// If this is the name of your control
}

Another method to look at is Form.Activate. This is probably better to use in this context

Also, ActiveControl might be helpful.

Answer 3

For Win32/C++, send the WM_CHANGEUISTATE message to the parent window:

    // Enable focus rect and accelerator underline in all controls.
    ::SendMessage(WM_CHANGEUISTATE, MAKELONG(UIS_CLEAR, UISF_HIDEACCEL | UISF_HIDEFOCUS), 0);