将变量(时间)从一种形式传递到另一种形式C#

Question

假设我有两种形式.第一个包含开始按钮,另一个是停止按钮.有没有办法可以确定按下开始和停止按钮之间经过的时间,并以第二种形式显示.

我尝试这样做并得出这些代码

表格1:开始按钮

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
    public DateTime startTime2;
    public DateTime endTime;
    public TimeSpan ts_timeElapsed;
    public string s_timeElapsed;


    public Form1()
    {
        InitializeComponent();
    }

    private void StartButton_Click(object sender, EventArgs e)
    {
        startTime2 = DateTime.Now;
        Form2 frm = new Form2();
        frm.Show();
        this.Hide();


    }

    private void Button2_Click(object sender, EventArgs e)
    {
        Instructions frm = new Instructions();
        frm.Show();
        this.Hide();

    }


}
}

表格2:停止按钮

namespace WindowsFormsApplication1
{
public partial class RoadSign1Meaning : Form
{
    public DateTime startTime1;
    public DateTime endTime;
    public TimeSpan ts_timeElapsed;
    public string s_timeElapsed;

    public RoadSign1Meaning()
    {
        InitializeComponent();
    }
    public string GetElapsedTimeString()
    {
        int days = ts_timeElapsed.Days;
        int hours = ts_timeElapsed.Hours;
        int mins = ts_timeElapsed.Minutes;
        int secs = ts_timeElapsed.Seconds;
        string x = "";
        if (days != 0)
        {
            x += days.ToString() + ":";
        }
        if (hours != 0)
        {
            x += hours.ToString() + ":";
        }
        if (mins != 0)
        {
            x += mins.ToString() + ":";
        }
        if (secs != 0)
        {
            x += secs.ToString();
        }

        return x;
    }

    private void StopButton_Click(object sender, EventArgs e)
    {
                   endTime = DateTime.Now;
        ts_timeElapsed = (endTime - startTime1);
        s_timeElapsed = GetElapsedTimeString();
        ElapsedLabel.Text = "Time Elapsed: " + s_timeElapsed;

        Form3 frm = new Form3();
        frm.Show();
    }
}
}

然而,问题是表格1的时间值不保存,因此表格2显示错误的经过时间值.有什么建议让我的代码有效吗？谢谢!

Answer 1

将开始时间传递给第二种形式

private void StartButton_Click(object sender, EventArgs e)
{
    Form2 frm = new Form2(DateTime.Now);
    frm.Show();
    this.Hide();
}

然后使用它

public partial class Form2 : Form
{
    private DateTime startTime;

    public Form2(DateTime startTime)
    {
        InitializeComponent();
        this.startTime = startTime;
    }

    private void StopButton_Click(object sender, EventArgs e)
    {
        endTime = DateTime.Now;
        ts_timeElapsed = (endTime - startTime);
        s_timeElapsed = GetElapsedTimeString();
        ElapsedLabel.Text = "Time Elapsed: " + s_timeElapsed;

        Form3 frm = new Form3();
        frm.Show();
    }     
}