C# winforms / UserControls - How to trigger Event from UserControl1 to UserControl2

Question

I am trying to trigger a Button1_Click event located in UserControl2 from UserControl1.

Controls are Loaded dynamically from my Main Form

//UserControl2
public partial  class ItemsModule : UserControl
{
        private void ButtonRefreshProperties_Click(Object sender, EventArgs e)
        {
            RefreshControls();
        }
        public void RefreshControls()
        {
            SomeCode();
        }
}

/// MainForm this is how i add the Control from the Main Form

ItemsModule im = new ItemsModule();
im.Name = "ItemsModule";
flpModules.Controls.Add(im);

//UserControl1
public partial class TreeViewControl :  UserControl
{
    private void ItemTreeView_MouseDoubleClick(Object sender, MouseEventArgs e)
    {
        String ItemId = ItemTreeView.SelectedNode.Name;
        Variables.CurrentItemID = ItemId;
        if (LoadedModules.Items)
        {
            //Here I would like a way to trigger ItemsModule.ButtonRefreshProperties_Click
        }
    }

}  

Answer 1

UserControl1 will need to have a references to UserControl2 . Once you have a reference UserControl1 should call a method on UserControl2 that causes the event to be raised.

You can pass the reference to UserContro2 in to UserControl1 via the constructor, a sub, or a property depending on how your application is structured. You should store the reference in a private field of UserControl1 so that you can access it from the DoubleClick event handler.

It is also possible to set this up in other ways. You could make UserControl2 be a property on the parent form, then UserControl1 can cast it's .Parent property in to the correct type and use that property as a reference.

You could also set up a 3rd class as a singleton that has a reference to UserControl2 .

The thing that all these solutions have in common is that somehow UserControl1 needs to have a reference to UserControl2 to be able to do anything with it.

You could avoid the reference problem by having UserControl1 raise an event that it's parent form listens for. Since the parent form should already have a reference to all the controls on it, you can make the form proxy the calls in to UserControl2 for you.