Visual Basic Saving Form info on hide - winforms

Question

Im using Visual Basic 2008
I have 2 forms
Main, EditCustomerInfo
Main form contains the following
Public Class Main
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
EditCustomerInfo.ShowDialog()
End Sub
EditCustomerInfo contains a text box and the following
Public Class EditCustomerInfo
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If Not CustomerIDTextBox.Text = "" Then
Me.Close()
Else : Me.Hide()
End If
End Sub
WHAT IT DOES:
So with this code alone when i debug the program it takes me to the main form and allows me to click a button to open the editcustomerinfo form
When im on the editcustomerinfo form i have a textbox and a button. If something is typed in the textbox and the button is clicked then the form hides, if nothing is typed in the textbox when the button is clicked then the form closes.
WHAT I WOULD LIKE IT TO DO:
If something is typed in the textbox i would like the button on the editcustomerinfoform to hide the editcustomerinfoform and also create a button on main form that allows the user to bring the editcustomerinfo form back up with what was typed in the text box.
Suggestions?

Answer 1

Automatic behavior, such as this, always worries me. How do you know when a user has completed their input without a lost focus event. If there are no other controls on the screen, then users won't readily know how to trigger the event. That being said, you can use a timer to delay the screen closing from a KeyPress event.
Public Class EditCustomerInfo
Private WithEvents userInputDelay As Timer = New Timer() With {.Interval = 1000} REM 1 second delay for next user input
Public ReadOnly Property CustomerId As String
Get
Return CustomerIDTextBox.Text
End Get
End Property
Private Sub CustomerIDTextBox_KeyPress(sender As Object, e As KeyPressEventArgs) Handles CustomerIDTextBox.KeyPress
userInputDelay.Enabled = False
REM Reset the timer
userInputDelay.Enabled = True
End Sub
Private Sub userInputDelay_Tick(sender As Object, e As KeyPressEventArgs) Handles userInputDelay.Tick
If Not CustomerIDTextBox.Text = "" Then
Me.Close()
Else : Me.Hide()
End If
End Sub
End Class
Add a button (Button2) to your Main. The code below will hide Button1 when the EditCustomerInfo.Textbox1.Text value is null/blank/white space. Button2's visibility is always the inverse of Button1.
Private EditCustomerInfoInstance As New EditCustomerInfo
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
EditCustomerInfoInstance.ShowDialog()
Button1.Visible = String.IsNullOrWhiteSpace(EditCustomerInfoInstance.CustomerId)
End Sub
Private Sub Button1_VisibleChanged(sender As Object, e As EventArgs) Handles Button1.VisibleChanged
Button2.Visible = Not Button1.Visible
End Sub