Form Switching

Form Switching

• Igal Chariski

  Also, I cannot seem to get your "My" method working. It always comes up as invalid syntax.
  
  

• CMeister

  VB 2005 / Express makes something like this very simple and much more robust.

  You should definately download vb express and give it a try (its free) and you can see a lot of the new features.

  
  

• brianpmccullough

  i can see potential problems with the code youve shown

  There is still nothing to stop creating second instances of forms.

  The variables in the form arent type specific - i could store any form in any of these variables.

  The general concept of the variables in a module globally accessible within you application is really what the my.forms collection in express/2005 is all about but this collection means that you only have a single instance of a given type and that when you add a new form type to your project you dont need to add another variable to a module.

  Also the practice of simply hiding the forms rather than closing then - what happens if the user actually wants to close them like when you close an application.   instead of simply creating a form, you need to check the reference is set an if it is make it visible, if it isnt create a new instance then show it and set the module variable, so two different conditions as to form creation/visibility.

  great if this code works for you, but it does have some limitations.

   

  
  

• MeMyselfNDotnet

  I'll do that. Thanks for the advice.
  
  

• CDFITGUY

  Ahh, ok. This is the problem then I guess, as I'm using VB.NET2003... I'm old-school lol

  Thanks for your contribution. Even though the code itself didn't answer my query, the theory behind it led me to write mine, so thank you very much for your help.

  
  
  

• VCBeginer

  Thank you for the response. If I was to use your second example to define a reference variable, is there any way I can set that up to be public across the entire project so that multiple forms can access multiple other forms, instead of having to use a single form as a base for opening everything
  
  

• sk78

  The way you can do this is with a default instance form and the My.Forms collections.

  So you would refer to a for as

  My.Forms.<Form Class Name>

  and this will refere to a single default instance.

  Then you can say

  My.Forms.Form2.Text = "foo"
  My.Forms.Form2.Show

  If you want to define a reference variable you can use something like

  Dim x as Form2
  X= my.Forms.Form2
  With X
  .text = "foo"
  .show
  End With

  With this you dont have to bother about instancing the forms - there will only be one instance of my.Forms.Form2 in the application.

  
  

• Smola

  you are using vb express or 2005, this is a new feature in this version. if your not then you'll need to have to do a bit of work to in essence create a forms collection.

  
  

• VolcanoDan

  Well, I've found the solution. Simply create a module declaring each variable name you wish to use for each form you will reference, like so:

  Module Module1
  Public X As Form
  Public Y As Form
  Public Z As Form
  End Module

  Then, in the load event of the first form loaded in your project, populate these variables with the forms you will be referencing, like so:

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
  Handles MyBase.Load

  X = New Form1
  Y = New Form2
  Z = New Form3

  End Sub

  Then, when you wish to reference an aspect of any of those forms, you simply use that reference variable.

  However, to prevent your forms from disposing, you must stop the close event and replace it with a Hide event. You do this in the Form_Closing event, like so:

  Private Sub Form2_Closing(ByVal sender As Object, ByVal e As _
  System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

  e.Cancel = True

  Me.Hide()

  End Sub

  I hope this helps someone.

  
  
  
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