control properties and methods access problem

erictamlam · April 13th, 2007, 09:51 PM

Hey Experts
I wanna know how to access control properties and methods in another different window.
for example,I created a window application containing more than just one window.In the Main Window,I click an item of StripMenu and another window will pop up. In this window,how can I access control properties and methods in the main window?
I serched online but got no ideal solvement.I need to declare public property in the main window?
great appreiciation,kinda urgent.

ERIC

planoie · April 14th, 2007, 08:32 AM

In order to access control properties from another form, you need to provide a public property on the form containing the control that exposes the desired property or the whole control. For example, if you had a login form with a user name textbox, you could expose just the text of the textbox:

public class MyForm : Form{
   ...
   public string UserName{
      get{ return txtUserName.Text; }
      set{ txtUserName.Text = value; }
   }
   ...
}

-Peter

erictamlam · April 14th, 2007, 11:40 PM

What if I want to access control methods from another form?thanks for helping me!

ERIC

planoie · April 15th, 2007, 09:55 AM

You could expose the control itself publicly on the form and do whatever you like. However, this is not the best design practice. What would happen if you wanted to change the control type within the form? Instead of exposing the control itself, expose the properties and/or methods you need to use. This is a safer way of doing it by encapsulating the functionality. Obviously, this will result in more individual property accessors and method wrappers, but in the end it's safer.

-Peter

erictamlam · April 16th, 2007, 03:07 AM

I'm sorry,but could you please be more specific? How can I expose control method in a form and then access the method in another form? and you mentioned that I can expose the control itself publicly on the form,how to make it?
GREAT GREAT APPRECITION!

ERIC

bschleusner · April 16th, 2007, 07:45 AM

If I understand what you are asking, then you could do it something like this.

Form1.Username = "abc";

There are 10 types of people - Those who understand binary, and those who don't.
http://bschleusner.googlepages.com/home

planoie · April 16th, 2007, 08:29 AM

Create a public property of the type of the control you want to expose. In the case of exposing a control, you should use a readonly property as it's unlikely you'll ever want to support re-assigning the control.

Code:

public class MyForm : Form{
   ...
   public TextBox UserNameControl{
      get{ return txtUserName; }
   }
   ...
}

Then you can use that control from outside the form:

Code:

MyForm myFormInstance = new MyForm();

myFormInstance.UserNameControl.Text = "name";

However, like I suggested before, it's better practice to expose just the properties of the control you need to expose instead of the control itself. This is safer and often easier from the perspective of the consuming code.

-Peter

(Edit - Added formatting)

erictamlam · April 16th, 2007, 09:34 AM

Thanks for this detailed explanation.You already gave me tips how to create public property of a whole control.But how about creating public property of a specific method of a control?any way to realise it? This is really embarrassing and sorry for constant questions...
great appreciation.

ERIC

planoie · April 16th, 2007, 02:23 PM

If you want to expose a control method on the containing form, just write a method and call it internally:

Code:

public class MyForm : Form{
   ...
   public void DoSomething(){
      innerControl.DoSomething();
   }
   ...
}

-Peter