如何在图形界面中添加?

How to add in a GUI?

我几乎没有学习如何做 GUI。所以,我对这些东西很陌生。我在 visual stuidos 中使用 windows 表单应用程序。

我需要帮助来添加我在文本框中输入的所有三个输入。

旁注 - MessageBox.Show(sum) 下面有一条红线

这是我的代码:

public partial class Form1 : Form
{
    double principal;
    double rate;
    double terms;
    double sum;

    public Form1()
    {
        InitializeComponent();
    }

    private void inputTextBoxPrincipal_TextChanged(object sender, EventArgs e)
    {
        principal = Convert.ToDouble(inputTextBoxPrincipal.Text);
    }

    private void inputTextBoxRate_TextChanged(object sender, EventArgs e)
    {
        rate = Convert.ToDouble(inputTextBoxRate.Text);
    }

    private void inputTextBoxTerms_TextChanged(object sender, EventArgs e)
    {
        terms = Convert.ToDouble(inputTextBoxTerms);
    }


    private double add()
    {
        sum = principal + rate + terms;
        return sum;
    }

    private void clickButtonEnter_Click(object sender, EventArgs e)
    {
        MessageBox.Show(sum);
    }

}

如下更改 clickButtonEnter_Click 事件。

  private void clickButtonEnter_Click(object sender, EventArgs e)
        {
            double sum = add();
            MessageBox.Show(sum.ToString());
        }

编辑:您也不需要那些 TextChanged 事件。跟着就好了

public partial class Form1 : Form
{
    double principal;
    double rate;
    double terms;
    double sum;

    public Form1()
    {
        InitializeComponent();
    }    

    private double add()
    {
        principal = Convert.ToDouble(inputTextBoxPrincipal.Text);
        rate = Convert.ToDouble(inputTextBoxRate.Text);
        terms = Convert.ToDouble(inputTextBoxTerms);

        sum = principal + rate + terms;
        return sum;
    }

    private void clickButtonEnter_Click(object sender, EventArgs e)
    {
        double sum = add();
            MessageBox.Show(sum.ToString());
    }

}