C# 使用按键时会产生双重效果

我用C#制作了这个计算器，我有一个问题：当我按键盘上类似于1的键时，它会给我不正确的结果—双倍数字。我没有得到正确的结果

你知道我做错了什么吗

多谢各位

namespace Calculator
{
    public partial class Calculator : Form
    {
        Double value = 0;
        String operation = "";
        int i = 0;
        bool operation_pressed = false;
        bool button_dot = false;
        OperationClass class1 = new OperationClass();
        public Calculator()
        {
            InitializeComponent();
            this.KeyPreview = true;
            this.KeyPress += new KeyPressEventHandler(Calculator_KeyPress);
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        private void Calculator_Load(object sender, EventArgs e)
        {

        }

        private void Calculator_KeyPress(object sender, KeyPressEventArgs e)
        {
            if ((result.Text == "0") || (operation_pressed))
                result.Clear();
            switch (e.KeyChar)
            {
                // key press from 0-9
                case (char)48:
                case (char)49:
                case (char)50:
                case (char)51:
                case (char)52:
                case (char)53:
                case (char)54:
                case (char)55:
                case (char)56:
                case (char)57:
                    e.Handled = true;
                    result.Text += e.KeyChar.ToString();
                    break;
            }
        }

        private void button_Click(object sender, EventArgs e)
        {
            if ((result.Text == "0") || (operation_pressed))
                result.Clear();
            operation_pressed = false;
            Button b = (Button)sender;
            result.Text = result.Text + b.Text;
        }

        private void operator_click(object sender, EventArgs e)
        {
            Button b = (Button)sender;
            operation = b.Text;
            value = Double.Parse(result.Text);
            operation_pressed = true;
            equation.Text = value + " " + operation;
        }

        private void buttonCE_Click(object sender, EventArgs e)
        {
            result.Text = "0";
            equation.Text = "";
            button_dot = false;
        }

        private void buttonC_Click(object sender, EventArgs e)
        {
            result.Clear();
            value = 0;
        }

        private void buttonEqual_Click(object sender, EventArgs e)
        {
            equation.Text = "";
            button_dot = false;
            operation_pressed = true;
            if (operation != "")
                result.Text = class1.GetResult(operation, value, result.Text);
            else
                result.Text = result.Text + "";
        }

        private void buttonDot_Click(object sender, EventArgs e)
        {
            Button b = (Button)sender;
            if ((!button_dot && !operation_pressed) || result.Text == "0")
                result.Text = result.Text + b.Text;
            button_dot = true;
        }
    }
}

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我会把它从按键改为按键。这样，它只会在钥匙松开时启动

---

编辑：检查此信息：

您不需要在

结果中追加keychar。Text

（假设

结果

是您的

文本框

项），正如您在第

行。这条线是你输入的两倍

删除它，它将按预期工作。
您是否也在设计器中声明了事件处理程序。可能Calculator.designer.cs还声明了一个按键事件处理程序。例如：当我在键盘上按1时，结果是11。我用VS 2010进行调试，函数计算器（Keypress）运行了两次。请不要在问题标题中包含关于所用语言的信息，除非没有它就没有意义。标签就是为了这个目的。谢谢你的支持！我在
开关之前添加
if（！e.Handled）
。