private void textBoxAddWrite_KeyPress(object sender, KeyPressEventArgs e)
        {
            if ('0' > e.KeyChar || e.KeyChar > '9')//输入的按键值在‘0’～‘9’之间
            {
                if (e.KeyChar != 8)//不是backspace键
                    e.KeyChar = (char)0;//设定键值为0
            }