MDI question

Question

I want to access a rich text box in the Active MDI Child Form from the parent MDI form and may be any numbers of MDI Childs instance but I want to access the a public rich text box on the Active one , I try to use the ActiveMdiChild method but I can’t, And I can access it if I know the instance child form name only like: Form2 f=new Form2(); f.MdiParent=this; f.richTextBox1.Text="John George"; What can I do? John George.

zngr2003 · Answer

thanks a lot Mr. nobrainer.

bilnaad · Answer

Yes just modify the returntype of the function prototype in the interface and the implementation in the class.

zngr2003 · Answer

sorry but i have new small question if that RichTextBox was modified as a user control and have some new functions is the getRichTextBox() can still be used or not.

zngr2003 · Answer

thanks a lot Mr. nobrainer

bilnaad · Answer

ActiveMdiChild return the active Form. Not the active Form2. You could try to implement an interface called IHaveRichtext public interface IHaveRichText { public RichTextBox getRichTextBox(); } and then have each form object implement this interface: public class Form1 : Form IHaveRichText { } public class Form2 : Form IHaveRichText { } The interface forces the object that implements it to adopt his methods. And this can be very usefull. When an object implements a interface you can cast the interface to clearify the object has the method to return the RichTextBox. ((IHaveRichText)ActiveMdiChild).getRichTextBox().Text = Yeeeehaaaaw!; I hope this post is clear enough to understand :) Good luck