views:

2626

answers:

5

How can invoke user control's public method from within the page?

I load the control dynamically inside OnInit on the page.Any ideas? For some reason I am getting a build error that says that the method doesn't exist, even though it's public. Starting to think that user controls are not worth all the hassle.

+1  A: 

Are you casting the User Control to the correct type?

Nick
+1  A: 

Without sample code it's hard to say for sure, but I'm guessing you need to cast your reference to the UserControl to the specific type of your custom control. For example, if your UserControl is of type "PersonControl", then your code would look something like this:

PersonControl ctl = (PersonControl)LoadControl("PersonControl.ascx");
ctl.DoCustomMethod();
Mike Powell
I tried casting, but that didn't work either:Control fracTemplateCtrl = (FracTemplateCtrl)LoadControl("FracTemplateCtrl.ascx"); Form.Controls.Add(fracTemplateCtrl); Response.Write(fracTemplateCtrl.TestMethod());error is that TestMethod is not found
gnomixa
Your fracTemplateCtrl also needs to be of type FracTemplateCtrl, in addition to the cast. The code in this comment is trying to call TestMethod on a variable of type Control.
Mike Powell
A: 

If your class is inheriting from UserControl, be sure that when you're accessing it, like others have said, you're casting it correctly. For instance:

public MyControl : UserControl
{
    public void MyMethod(){...}
}

in your form:

private MyControl mycontrol = new MyControl();
private void MainForm()
{
    this.Controls.Add(mycontrol);

    InitializeComponent();
}

private void DoStuff()
{
    ((MyControl)mycontrol).MyMethod();
}
SnOrfus
A: 

Mike's answer is how it's done, but Visual Studio can be a bit wonky about detecting the UserControl class, and complain that the type doesn't exist. In those situations I've have to add a <% @Reference %> tag on the page to force it to recognize, even though it may be referenced in the web.config.

Adam Lassek
+3  A: 

You've said

Control fracTemplateCtrl = 
   (FracTemplateCtrl)LoadControl("FracTemplateCtrl.ascx")
fracTemplateCtrl.TestMethod();

you need to say

FracTemplateCtrl fracTemplateCtrl =
   (FracTemplateCtrl)LoadControl("FracTemplateCtrl.ascx")
fracTemplateCtrl.TestMethod();

Note that fracTemplateCtrl is declared as a FracTemplateCtrl, so visual studio knows that it has a TestMethod(). When it is declared as a Control, visual studio can't make this assumption.

Daniel LeCheminant
@gnomixa: No problem. Note that you would have gotten your answer much more quickly had you posted your code with the question! ;]
Daniel LeCheminant