Adding an event handler for a control in child form from parent form in C#

Question

I have two forms. One is a parent form with a button and a text box. On click of the button, a dialog opens the child form which in turn has a textbox and a button. Now what

Answer 1

You can add event in child form and rise it when text changed. Then create event handler in parent form and change text in parent form. In child form:

public event EventHandler OnChildTextChanged;
private void textBox1_TextChanged(object sender, EventArgs e)
{
    if(OnChildTextChanged != null)
       OnChildTextChanged(textBox1.Text, null);
}

In parent form:

private void button1_Click(object sender, EventArgs e)
{
    ChildForm child = new ChildForm();
    child.OnChildTextChanged += new EventHandler(child_OnChildTextChanged);
    child.ShowDialog();
}

void child_OnChildTextChanged(object sender, EventArgs e)
{
    textBox1.Text = (string)sender;
}

Hope it helps.