When overriding the Focused property in a derived class, use the base class's Focused property to extend the base implementation. Otherwise, you must provide all the implementation.
The following code example disables a MenuItem if a TextBox does not have focus. This example requires that you have a Form with a TextBox named textBox1 and two MenuItem objects named menuItemEdit and menuItemEditInsertCustomerInfo.
privatevoid menuItemEdit_Popup(object sender, EventArgs e)
{
// Disable the menu item if the text box does not have focus.this.menuItemEditInsertCustomerInfo.Enabled = this.textBox1.Focused;
}