Is there any case in which the Form's Activated event is not raised?

Question

I don't understand why it could be that, I thought Activated should be raised when the form is shown. In fact my form has TopLevel set to false and it's added to another form. When the main form shows, it's also visible, and I can interact with its controls but I tested and saw that the Activated is not raised.

public MainForm(){
     InitializeComponent();
     Form child = new Form();
     child.Activated += (s,e) => {
        MessageBox.Show("Activated!");
     };
     child.Size = new Size(200,100);
     child.TopLevel = false;
     child.Show();
     child.Parent = this;
}

After running the MainForm the child form is appeared inside the main one and there isn't any MessageBox displayed with the message "Activated!".

What is the additional job to do to make it raise?

Answer 1

If the second form comes to screen for the first time, you can use Shown event.

Activate event is only fired when a form gets focus, but that does not contain showing for the first time. But, if the previous form which is active is outside of your app, it will not raise activate event. I mean it is valid when only viewing forms of same project.