How to talk between forms not directly related?

[jenn5175]

Okay, I have 3 Windows forms - FormA, FormB, FormC. FormA is the main form which has a datagrid of all shipping containers for a certain shipment pulled from a SQL db. I use a function dgFill() on FormA to fill this when a shipment is chosen from a combobox on FormA. If the user wants to add a container, I have a cmd button on FormA which opens FormB - containing a textbox to fill in the barcode of the new container (this will eventually get changed to a barcode scanning module) and a cmd button to add container. Once the cmd button is clicked FormB hides, the new container is added, and FormC opens which allows them to add items to the new container. Once they are done adding items, I want to have a button which not only closes FormC, but refreshes the datagrid in FormA. If FormA had opened FormC I know how to reference dgFill() and call it from FormC before hiding FormC. But because FormB is the parent of FormC, I am at a loss. Simply put:

 

FormA -> opens FormB

FormB -> opens FormC

FormC -> refeshes FormA

 

I was thinking either (a) if I could call dgFill() from FormC before hiding it or (b) have some sort of "OnFocus" function on FormA so it refreshes everytime FormA is brought into focus.

 

Any thoughts?

Jenn

[PlausiblyDamp]

You will need to pass a reference to formA to FormB and then get formB to pass the formA reference to FormC - then formC can access FormA

 

Hope that makes a bit of sense.

[bfellwock]

From what you have written I don't see why you would have to hide formB. Why not just dispose of FormB and then Show FormC. Or just use an input box to get the barcode value i.e. myValue = InputBox(message, title, defaultValue) and then show formB. Hope this helps.

[jenn5175]

PlausiblyDamp,

How can I pass a reference for a function? Can you point me to a tutorial? I know how to pass variables but not how to pass a function reference. Thanks!

 

Jenn

[dynamic_sysop]

here's a quick example i put you together :

In Form1 :

   Dim frm2 As New Form2()

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       Me.AddOwnedForm(frm2) '/// make Form2 owned by Me

   End Sub

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       frm2.Show()
   End Sub

 

In Form2 :

   Dim frm1 As Form1
   Dim frm3 As New Form3()
   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       frm1 = Owner
       AddOwnedForm(frm3)
       frm3.Show()
   End Sub

   Public Function DoStuff(ByVal strString As String)
       frm1.TextBox1.AppendText(strString)
   End Function

 

In Form3:

   Dim f2 As form2

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       f2 = Owner
       f2.DoStuff("some stuff")
   End Sub

 

here's a sample source i included to make it easier to understand ...

passing stuff between forms.zip

[dynamic_sysop]

you need to make a sort of chain , in form1 you make a new form2 , then add it as owned by form1

Dim frm2 As New Form2() '/// make it new.

AddOwnedForm(frm2) '/// make Form2 owned by Form1

 

then when you have form2 open , you make a new Form3 , making that owned by Form2

Dim frm3 As New Form3()'/// make a new Form3 , from inside Form2.

AddOwnedForm(frm3)'/// add it as owned by Form2

 

make a Function inside Form2 , which will pass data to Form1 ( this will be triggered via Form3

 Public Function DoStuff(ByVal strString As String)
       frm1.TextBox1.AppendText(strString)
   End Function

in your 3rd Form

Dim f2 As form2

       f2 = Owner
       f2.DoStuff("some stuff")

the attached source will make it easier.