C#文本框输入验证控件的使用

 1private void textBox2_Validating(object sender, CancelEventArgs e)
 2        {
 3            if (textBox2.TextLength>0 && (textBox2.TextLength!=5))
 4            {
 5                errorProvider1.SetIconAlignment((Control)sender,ErrorIconAlignment.MiddleRight);
 6                errorProvider1.SetError((Control)sender,"TextLength>0 && TextLength!=5");
 7                e.Cancel=true;
 8            }
 9            else
10            {
11                errorProvider1.SetError((Control)sender,"");
12            }
13        }