Question

I have a User Control with with some search functionality, then I also have a control that contains a grid. In the control that has the grid I have all the functionality to retrieve some items I need to populate a report from the search control.

My question is, and I have read about this but not completely sure how to make it work, I read i need to register a event handler in control A that calls the function in control B. How does that work?

Say in control B there is a function that I need to call GetAllItemsByRegistrantID(int id). How can I make a call to this function from control A?

I would really appreciate any help or guidance on this.

Regards

Answer 1

Here is an example if you had to do it using events.

On your first user control (the search control) define a custom event.

public partial class UserControl1 : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    public event EventHandler<MyCustomeEventArgs> MyCustomClickEvent;

    protected virtual void OnMyCustomClickEvent(MyCustomeEventArgs e)
    {
        if (MyCustomClickEvent != null)
            MyCustomClickEvent(this, e);

    }

    public void button1_Click(object sender, EventArgs e)
    {
        OnMyCustomClickEvent(new MyCustomeEventArgs(5));
    }

}
public class MyCustomeEventArgs : EventArgs
{
    public MyCustomeEventArgs(int searchID)
    {
        SearchID = searchID;
    }
    public int SearchID { get; set; }

}

On your user control with the grid, define a handler.

public void HandleCustomEvent(object sender, MyCustomeEventArgs e)
{
    GetAllItemsByRegistrantID(e.SearchID);
}

public void GetAllItemsByRegistrantID(int id)
{
    Label1.Text = id.ToString();
}

On the page where they both live, wire them together.

protected void Page_Load(object sender, EventArgs e)
{
    UserControl1Instance.MyCustomClickEvent += UserControl2Instance.HandleCustomEvent;
}