int Number;
                Number = int.Parse(a.Text);


                if (Number == (int)Number)

                    b.Text = "该数字为整数";
                else
                    b.Text = "该数字不是整数";



if (Number == (int)Number) 这里出错了，，，，不懂

输入小数还不能判断，问题不大，自己看看吧，谢谢啦

嘿嘿，解决，不过不是很理解，刚刚学.....

谢谢啦