C#中点击窗体右上角的X然后询问是否关闭,是就关闭,不是就什么都不做

 
private void TestForm_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("确定要关闭？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
e.Cancel = false;
this.Dispose();
}
else
{
e.Cancel = true;
}
}