Call parent page function from user control

Question

I have a Default.aspx page and I am using a usercontrol in it. On some condition in usercontrol.cs I have to invoke a function present in Default.aspx.cs page (i.e parent page of user control). Please help and tell me the way to do this task.

Answer 1

You have to cast the Page property to the actual type:

var def = this.Page as _Default;
if(def != null)
{
    def.FunctionName();
}

the method must be public:

public partial class _Default : System.Web.UI.Page
{
    public void FunctionName()
    { 

    }
}

But note that this is not best-practise since you are hard-linking the UserControl with a Page. Normally one purpose of a UserControl is reusability. Not anymore here. The best way to communicate from a UserControl with it's page is using a custom event which can be handled by the page.

Mastering Page-UserControl Communication - event driven communication

Answer 2

Add an event to the user control:

public event EventHandler SpecialCondition;

Raise this event inside your user control when the condition is met:

private void RaiseSpecialCondition()
{
    if (SpecialCondition != null) // If nobody subscribed to the event, it will be null.
        SpecialCondition(this, EventArgs.Empty);
}

Then in your page containing the user control, listen for the event:

public partial class _Default : System.Web.UI.Page
{
    public void Page_OnLoad(object sender, EventArgs e)
    { 
        this.UserControl1.OnSpecialCondition += HandleSpecialCondition;
    }

    public void HandleSpecialCondition(object sender, EventArgs e)
    {
        // Your handler here.
    }
}

You can change the EventArgs to something more useful to pass values around, if required.

Answer 3

parent.aspx.cs

public void DisplayMsg(string message)
{
    if (message == "" || message == null) message = "Default Message";
    Response.Write(message);
}

To Call function of parent Page from user control use the following: UserControl.ascx.cs

 this.Page.GetType().InvokeMember("DisplayMsg", System.Reflection.BindingFlags.InvokeMethod, null, this.Page, new object[] { "My Message" });

This works fine for me..

Answer 4

Try this

 MyAspxClassName aspxobj= new MyUserControlClassName();
    aspxobj.YourMethod(param);