这是我用窗体编的计算器代码，计算结果都不对，求解释,有附件（只编到计算的...)
namespace ex4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Button btn = sender as Button;
            textBox1.Text = textBox1.Text + btn.Text;
            
        }
        string a ;
        string f;
        int num1;

        private void button14_Click(object sender, EventArgs e)
        {
            Button btn = sender as Button;
            a = textBox1.Text;
            num1 = Convert.ToInt32(a);
            textBox1.Text = "";
            f = btn.Text;
            


        }
        
        private void button18_Click(object sender, EventArgs e)
        {
            if (f == "+")
            {
                int c = num1 + Convert.ToInt32(a);
                textBox1.Text = Convert.ToString(c);
            }
            else if (f == "-")
            {
                int c = num1 - Convert.ToInt32(a);
                textBox1.Text = Convert.ToString(c);
            }
            else if (f == "*")
            {
                int c = num1 * Convert.ToInt32(a);
                textBox1.Text = Convert.ToString(c);
            }
            else if (f == "/")
            {
                int c = num1 / Convert.ToInt32(a);
                textBox1.Text = Convert.ToString(c);
            }

        }  
    }
}

你在加两个相同的数，没有一点逻辑！

的确乱的很！！

好好学习后再做吧！你的基础不太好！

木有办法啊，刚学个皮毛老师就叫做计算器了......

我这里有一个例子，不过写的比较繁琐，仅供参考

 public partial class Form1 : Form
    {
        public double dblFirst = 0;
        public double dblSecond = 0;
        public bool blnFirstOpen = true;
        public bool blnClear = false;
        public string strOper;
        public Form1()
        {
            InitializeComponent();
        }

        private void button0_Click_1(object sender, EventArgs e)
        {
            if (sender == button0) append_num(0);
        }
        private void button4_Click(object sender, EventArgs e)
        {
            if (sender == button4) append_num(1);
        }

        private void button8_Click(object sender, EventArgs e)
        {
            if (sender == button8) append_num(2);
        }

        private void button12_Click(object sender, EventArgs e)
        {
            if (sender == button12) append_num(3);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (sender == button3) append_num(4);
        }

        private void button7_Click(object sender, EventArgs e)
        {
            if (sender == button7) append_num(5);
        }

        private void button11_Click(object sender, EventArgs e)
        {
            if (sender == button11) append_num(6);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (sender == button2) append_num(7);
        }

        private void button6_Click(object sender, EventArgs e)
        {
            if (sender == button6) append_num(8);
        }

        private void button10_Click(object sender, EventArgs e)
        {
            if (sender == button10) append_num(9);
        }
           
        private void append_num(int i)
            {
                if(blnClear)
                {
                    if(blnFirstOpen==true)
                        dblFirst=Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond=Convert.ToDouble(textBox1.Text);
                    textBox1.Text="";
                    blnClear=false;
                }
                if(((i==0)&&(textBox1.Text!=""))||(i!=0))
                    textBox1.Text=textBox1.Text+i.ToString();
            }

           
        
            private void btn_equ_Click_1(object sender, EventArgs e)//等号的处理
            {
                if (textBox1.Text != "")
                    if (blnFirstOpen == true)
                        dblFirst = Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond = Convert.ToDouble(textBox1.Text);
                switch (strOper)
                {
                    case "+":
                        dblFirst += dblSecond;
                        break;
                    case "-":
                        dblFirst -= dblSecond;
                        break;
                    case "*":
                        dblFirst *= dblSecond;
                        break;
                    case "/":
                        dblFirst /= dblSecond;
                        break;
                }

                strOper = "=";
                blnFirstOpen = false;
                textBox1.Text = Convert.ToString(dblFirst);
                blnClear = true;
            }
            private void btn_clear_Click(object sender, EventArgs e)//清空文本框
            {
                dblFirst = 0;
                dblSecond = 0;
                blnFirstOpen = true;
                blnClear = false;
                textBox1.Text = "";
                textBox1.Focus();
            }

            private void btn_dot_Click_1(object sender, EventArgs e)//小数点的处理办法
            {
                if (textBox1.Text == "")
                    textBox1.Text = "0.";
                else if(textBox1.Text=="0..")
                    MessageBox.Show("小数不能函数两个小数点！");
                else
                    textBox1.Text = textBox1.Text + ".";
                blnClear = false;
            }

            private void btn_plus_Click_1(object sender, EventArgs e)//加法的实现函数
            {
                if (textBox1.Text != "")
                    if (blnFirstOpen == true)
                        dblFirst = Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond = Convert.ToDouble(textBox1.Text);
               
                if (sender == btn_plus)
                    strOper = "+";
                else if (sender == btn_minus)
                    strOper = "-";
                if (sender == btn_mul)
                    strOper = "*";
                if (sender == btn_div)
                    strOper = "/";
                blnFirstOpen = false;
                textBox1.Text = Convert.ToString(dblFirst);
                blnClear = true;
            }

            private void btn_minus_Click(object sender, EventArgs e)//减法的实现函数
            {
                if (textBox1.Text != "")
                    if (blnFirstOpen == true)
                        dblFirst = Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond = Convert.ToDouble(textBox1.Text);
               
                if (sender == btn_plus)
                    strOper = "+";
                else if (sender == btn_minus)
                    strOper = "-";
                if (sender == btn_mul)
                    strOper = "*";
                if (sender == btn_div)
                    strOper = "/";
                blnFirstOpen = false;
                textBox1.Text = Convert.ToString(dblFirst);
                blnClear = true;
            }

            private void btn_mul_Click(object sender, EventArgs e)//乘法的实现函数
            {
                if (textBox1.Text != "")
                    if (blnFirstOpen == true)
                        dblFirst = Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond = Convert.ToDouble(textBox1.Text);
               
                if (sender == btn_plus)
                    strOper = "+";
                else if (sender == btn_minus)
                    strOper = "-";
                if (sender == btn_mul)
                    strOper = "*";
                if (sender == btn_div)
                    strOper = "/";
                blnFirstOpen = false;
                textBox1.Text = Convert.ToString(dblFirst);
                blnClear = true;
            }

            private void btn_div_Click(object sender, EventArgs e)//除法的实现
            {
                if (textBox1.Text != "")
                    if (blnFirstOpen == true)
                        dblFirst = Convert.ToDouble(textBox1.Text);
                    else
                        dblSecond = Convert.ToDouble(textBox1.Text);
               
                if (sender == btn_plus)
                    strOper = "+";
                else if (sender == btn_minus)
                    strOper = "-";
                if (sender == btn_mul)
                    strOper = "*";
                if (sender == btn_div)
                    strOper = "/";
                blnFirstOpen = false;
                textBox1.Text = Convert.ToString(dblFirst);
                blnClear = true;
            }

            private void Form1_Load(object sender, EventArgs e)
            {

            }        

           

          
          
           
        }

求大神带

求大神带

想问你的能实现不按=，按运算符也能出结果，比如说6+1，不按等号，再按+号，能显示出7来吗？

不行，也在为这个发愁呢.....