D{`BBE_UPSU{ORG1B$I3_%F.png (上传于2019-03-23 17:23:10)

void Button1Click(object sender, EventArgs e)
        {
            double d=0;
            string b=textBox2.Text.ToString();
            double a=double.Parse(textBox1.Text);
            double c=double.Parse(textBox3.Text);

            if("b"=="+")
                d=a+c;
            else if("b"=="-")
                d=a-c;
            else if("b"=="*")
                d=a*c;
            else if("b"=="/")
                d=a/c;
            else
            MessageBox.Show("亲，超出我的能力范畴了哦！","这是一个弱弱的的警告yeah~！");
            textBox4.Text=d.ToString();