Accessing a checkbox from a class

matthew king

Experts,

Is it possible to set a checkbox checked value to true via a class residing outside of the form the checkbox resides in. Specifically, I would like to have my class search for certain parameters and set the checkbox on the main form to checkbox.checked = true. Currently, my class does not recognize the checkbox "…does not exist in the current content"). So, how do I get my class to "see" the checkbox, and then set it's value to checked? I would appreciate an example, if possible.

4 Replies

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Vulpes14y ago
Accepted answer
First of all, I'd change the Modifiers property of your CheckBox from private to internal so that it can be accessed by other classes within the same application. You can do this from the Properties Box.

Secondly, your class needs a reference to the form which it's on. There are many ways of obtaining such a reference but here's one of them.

Suppose the form is called Form1 and that the CheckBox (checkBox1 say) is placed directly on the form and is not within some other container such as a Panel or GroupBox.

Then you can change it's Checked property as follows:

Form1 f1 = (Form1)Application.OpenForms["Form1"];
f1.checkBox1.Checked = true;
Sam Hobbs14y ago
The advantage of a property is that if you later need to do something more than just get or set the checked property of the chckbox then you probably only need to modify the form class but not anywhere that the certain parameter is modified. For small projects it odes not matter much but it can really help for larger projects. If you learn the technique with a small project then you will already be in the habit of doing it for large projects.
Sam Hobbs14y ago
I would not do it by changing the Modifiers property of the CheckBox. A more flexible and object-oriented solution would be to do something more like what Senthilkumar suggests, except you do not need to create a class. If there is a benefit to making a class as Senthilkumar suggests then I hope Senthilkumar clarifies how to use it.

You can create a method or property of the form. Properties is something that language experts consider to be good. It is often difficult to understand the value of properties and other object-oriented features but language experts have learned the value of adding a little abstraction can be very beneficial. Something like the following.
public bool CertainParameter

{

get { return checkBox1.Checked; }

set { checkBox1.Checked = value ; }

}
Senthilkumar14y ago
Hi,

I think you do not have control on class which actually having the status of the control in another form.

But what you can do is, you can create the custom class with properties which actually maintains the status of the controls.

public class ControlStates
{
public bool checkbox1{get;set;}
}

The above class can maintain the state of the control.