How to disable the parent form when a child form is active?

Question

How to disable a parent form when child form is active using c#?

Answer 1

ChildForm child = new ChildForm();
child.Owner = this;
child.Show();

// In ChildForm_Load:

private void ChildForm_Load(object sender, EventArgs e) 
{
  this.Owner.Enabled = false;
}

private void ChildForm_Closed(object sender, EventArgs e) 
{
  this.Owner.Enabled = true;
} 

source : http://social.msdn.microsoft.com/Forums/vstudio/en-US/ae8ef4ef-3ac9-43d2-b883-20abd34f0e55/how-can-i-open-a-child-window-and-block-the-parent-window-only