Question Passing Variables between Subs...

[ndavenport]

I'm having an issue where I need to pass the value in a variable from one sub to another. Here is the scenario. I have two forms; Main_Form and frmClient. I take a value from frmClient and pass it into a sub called Form_Activate located in Main_Form. I then need to take the value from Form_Activate and use it in a sub called when the user selects a menu item in the toolstrip.

Starting point is frmClient and the code there is this:

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

Dim Client As Integer
Client = cmbClient.SelectedValue
Main_Form.Form_Activate(Client)

End Sub

The value gets passed to the Main_Form sub names Form_Activate. This is working correctly and the value shows up as expected.

Public Sub Form_Activate(ByVal ClientReceived As Integer)

pintClient = ClientReceived

End Sub

Now here is where I run into the problem. I need to carry the value stored in pintClient to another sub on the form named UpdateDatabaseToolSTripMenuItem. This sub is called when the user clicks a menu item named Update Database.

Private Sub UpdateDatabaseToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UpdateDatabaseToolStripMenuItem.Click

'some code

End Sub

If I attempt to use the variable pintClient directly, it has a value of 0 by the time it is called in the UpdateDatabaseToolStripMenuItem_Click Sub.

 

[Solitaire]

You need to declare the variable with the Public keyword instead of Dim. Then use the fully-qualified name of the variable, which includes the name of the form when accessing it from another form. For example:

In Form1:

Public mydat As String
mydat = "whatever"


In Form2:

Dim value As String
value = Form1.mydat


Apply this general principle to your own code.

 

[ndavenport]

pintClient is a public variable, but when the second sub is called through the menu item click, it contains no data. It does contain data when originally set in the Form_Activate() sub. Both subs are on the same form.

As soon as the UpdateDatabaseToolStripMenuItem_Click sub is called, the pintClient variable resets back to 0 instead of maintaining it's value.

 

[JuggaloBrotha]

You need to declare the variable with the Public keyword instead of Dim. Then use the fully-qualified name of the variable, which includes the name of the form when accessing it from another form. For example:

In Form1:

Public mydat As String
mydat = "whatever"


In Form2:

Dim value As String
value = Form1.mydat


Apply this general principle to your own code.

That's what properties are for, instead of declaring the variable itself as public/friend you instead create a public/friend property.

 

[ndavenport]

So I tried to store the value in a label as a temporary fix to try to see better what is going on. When the UpdateDatabaseToolStripMenuItem_Click is invoked, it clears the text value in the label as well.

So instead of the variable in the Form_Active sub, I populated the text of the label. Not sure why the data returned from the Form_Active sub gets wiped out by the UpdateDatabaseToolStripMenuItem_Click sub. Clearing the value is the first thing that happens when run.

 

[BlackByte]

Have you tried declearing a global variable, i.e declearing the variable on top outside any Sub.

 

[ndavenport]

Have you tried declearing a global variable, i.e declearing the variable on top outside any Sub.

Yes, the pintClient is declared as public outside of any subs, right after public class

 

[JuggaloBrotha]

delete the bin and obj folders from the project, then zip the project and attach it to a post, something's not adding up.

 

[BlackByte]

Yeah, something's definitely not adding up. How could even the values in the label be reset. Unless you close the form...

 

[ndavenport]

Yeah, it really got me crossed...I decided to change routes and put the control on the main form. I was concerned about how this would look but I think I'm okay with it. Now it is working as well. Not sure what was going on, but I think at this point I'm moving on. Thanks for all the great feedback!