MDI Children

[Guest]

Yesterday, I posted a question about accessing controls on a child form. I had trouble understanding it. I am NOT rewriting this program, and need a way to work this out the way it is. Here is exactly what I'm dealing with: I have my main form(Form1), which contains a third-party main-menu and two third-party toolbars. Then there is its child form(frmTextControl) which contains a third-party text control set to fill docking. That is the only control on that form. When I have multiple instances of the child form(frmTextControl), I want to beable to assign the font of the active textcontrol ONLY. This would require access to the active MDI child form. I need to know how to name each intance of the child form, and to be able to have access to the active instance of the child form. And again, I don't want any alternate methods of accomplishing this, but how to do it with the setup I currently have. Thank You!

 

[Guest]

I noticed while in Form1, I could do "Form1.ActiveMdiChild" but it did not contain the control that I wanted. Is it possible to have the control listed within "Form1.ActiveMdiChild. Note: The textcontrol's modifier is set to public

----- I wrote: ----

Yesterday, I posted a question about accessing controls on a child form. I had trouble understanding it. I am NOT rewriting this program, and need a way to work this out the way it is. Here is exactly what I'm dealing with: I have my main form(Form1), which contains a third-party main-menu and two third-party toolbars. Then there is its child form(frmTextControl) which contains a third-party text control set to fill docking. That is the only control on that form. When I have multiple instances of the child form(frmTextControl), I want to beable to assign the font of the active textcontrol ONLY. This would require access to the active MDI child form. I need to know how to name each intance of the child form, and to be able to have access to the active instance of the child form. And again, I don't want any alternate methods of accomplishing this, but how to do it with the setup I currently have. Thank You!

 

[Andy Gaskell]

You can cast the ActiveMdiChild property. Let's assume you child forms are
*always* of type frmTextControl.

((frmTextControl)Form1.ActiveMdiChild).MySuperDooperDockingControl

I noticed while in Form1, I could do "Form1.ActiveMdiChild" but it did

not contain the control that I wanted. Is it possible to have the control
listed within "Form1.ActiveMdiChild. Note: The textcontrol's modifier is
set to public.

----- I wrote: -----

Yesterday, I posted a question about accessing controls on a

child form. I had trouble understanding it. I am NOT rewriting this
program, and need a way to work this out the way it is. Here is exactly
what I'm dealing with: I have my main form(Form1), which contains a
third-party main-menu and two third-party toolbars. Then there is its child
form(frmTextControl) which contains a third-party text control set to fill
docking. That is the only control on that form. When I have multiple
instances of the child form(frmTextControl), I want to beable to assign the
font of the active textcontrol ONLY. This would require access to the
active MDI child form. I need to know how to name each intance of the child
form, and to be able to have access to the active instance of the child
form. And again, I don't want any alternate methods of accomplishing this,
but how to do it with the setup I currently have. Thank You!

 

[Andy Gaskell]

Ok, here's an example. Let's say you have a button on Form1 called myButton
with an event handler called myButton_Click.

private void myButton_Click(object sender, EventArgs e)
{
TextControl tc = ((frmTextControl)this.ActiveMdiChild).myTextControl;
//This will be the name of the control that you have the public access
modifier on.
//Now do whatever you want with tc.
}

// You can cast the ActiveMdiChild property. Let's assume you child forms are
// *always* of type frmTextControl.
//
// ((frmTextControl)Form1.ActiveMdiChild).MySuperDooperDockingControl
//

My child form is always frmTextControl. I tried putting your code into

mine, but I don't know how to implement it. Could you tell me what form to
place it in, and in what context? Thank You Very Much!

 

[Martin Stainsby]

You can also use the "as" operator to do the cast. It doesn't raise an
exception on failure, instead it returns null.


private void myButton_Click(object sender, EventArgs e)
{
frmTextControl tc = this.ActiveMdiChild as frmTextControl;

//Again you can Now do whatever you want with tc.

if( tc != null )
{
tc.myFunc();
}
}