Field flashes when assigned value then disappears

[Bill Purkins]

Okay, someone explain this one. I retrieve the environment variable USERNAME and assign it to a string variable. I can even show it in a MSGBOX and it shows "Owner". In my code I want to assign the value to a text box when it gets focus. It does it, but it flashes blue and then disappears and the text box appears blank, but if I save the record and go back to it? The value is there.
Help?

Dim strUserName As String
        strUserName = Environment.GetEnvironmentVariable("USERNAME")
        MsgBox(strUserName)
        LogInNameTextBox.Text = Convert.ToString(strUserName)

[Teme64]

You didn't post the actual code you're using, right?

You're probably doing something like this

Private Sub TextBox1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.GotFocus
    '
    Dim strUserName As String
    strUserName = Environment.GetEnvironmentVariable("USERNAME")
    TextBox1.Text = Convert.ToString(strUserName)
End Sub

Change it to

Private Sub TextBox1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.GotFocus
  '
  Dim strUserName As String
  strUserName = Environment.GetEnvironmentVariable("USERNAME")
  TextBox1.Text = strUserName
  TextBox1.SelectionStart = 0
  TextBox1.SelectionLength = 0

End Sub

and remove Convert.ToString(). You're converting a string to a string, no need to do that.

[Bill Purkins]

Thanks for the tip but it didn't work. The field it fails to initialize is bound to a database table. When I try it on a plain text box, it works without the .select stuff.

Any thoughts?

Thanks,
Bill P.

[Teme64]

Ok. How's Environment.GetEnvironmentVariable("USERNAME") related to the db table? Do you read some value to the textbox, then change it in GotFocus and save back to DB?

[edgar5]

I've had a similar problem and it ended up a variable scope situation. Try this as a test...
Create a global variable (I'm note sure where would be appropriate in your code, if the is a generic Form put it in):

Public Class Form1
        Public userName As New StringBuilder

Then, in the sub where you retrieve USERNAME, instead of using a pointer to it (assigning it to a string), make a copy of it in the Public StringBuilder: userName = userName.Append(Environment.GetEnvironmentVariable("USERNAME")) Then use userName.ToString when you want this data. There are some problems with re-using StringBuilder Class as there is no Clear method (it is easy to write your own). If this solves the problem let us know!

[Bill Purkins]

thanks. will try.
bill p.