How to Pass Data Between Two MDI Forms

[Brunoz]

I have a main form as MDI parent and MDI child form, the child form shows a new form (I called it mydialog). I add a simple TLabel somewhere on that form, then i create a new child form from that window:
Application->Createform, and on this form, I include a simple Tbutton. I want to create a toolbar button on MDI form when user clicks it, it will get string from Active child form executing function GetStr.

[Chingum]

There should be no exception when setting the Owner property. To share data among the child MDI forms, create a public property in MDI parent/container form and access that property through out all your child form. Can you paste the exception ? Also could you paste your code that sets this value ? Have you set other properties like MDIParent / etc ? When you create your MDIChild, at the moment you are getting the overall executable to create this form for you (because you are using the Application->Createform).

[Pauline]

You should be able to access the properties and methods of the MDIChild form. To get an instance of an opened from, you can use this... Dim f2 As Form2 = CType(Application.OpenForms("Form2"), Form2), By including MDIParent.h in MDIChild.h, you should be able to access the properties and methods of the MDIParent form. If you look at the end of any of the auto-generated headers for any forms.

[BlackSunReyes]

I created an MDI application that opens two "child" forms when it loads. These child forms have a label and a button on them. When the button is clicked on one child form(Form2), it changes the text of the label on the other child form(Form3). I prefer to pass in any custom data or parameters to the Form by its constructor. It is the least "WinForms"-specific way and in fact is no different to constructing mostly any other object really.