Change the properties of controls from another form

[jpreciado]

In C#, I need to change the properties of controls on another form. For example, with a label control on Form 1, how can I change its text property from Form 2?

 

[JurkMonkey]

There are a few options. Some are easy, some are a pain. Here's 2 ideas for you:

1. Register your Form1 with Form2.

private Form1 myForm1

public Form2(Form1 pform)
{
InitializeComponents();

myForm1 = pform; //Set the local variable myForm1
//In form 2 to the calling code.
}

Then you can access functions and properties on your Form1. You might have to make the controls that you want to modify public. (public System.Windows.Form label1)

This is usually a BAD IDEA though. You are externally changing properties that should be private.

2. Have your Form2 throw events.

public event EventHandler UpdateLabelInfo;

Then in your form1 you would say:

private void button1_Click(object sender, eventargs e)
{
Form2 myForm2 = new Form2();
myForm2.UpdateLabelInfo += new EventHandler(myForm2_UpdateLabelInfo());
}

private void myForm2_UpdateLabelInfo()
{
//Set your properties in Form1
}

3. This is probably the best option. It works off a design pattern called "Model-View-Controller"

Basically, create a controlling class that handles all interaction between forms.

AppController myApp = new AppController();

myApp.SetForm1Label();

This would allow you to change the properties of Form1 from any form or control that has access to AppController.