C# 将一个列表的值除以另一个列表的值以生成一个新列表

Question

我希望将每个列表的对应值进行划分，以便生成一个新列表，其中包含我的两个列表中每个对应索引的划分结果。我的两个列表都是 8 个值长并且都是 int 列表。我目前正在创建两个要这样划分的列表：

private void StartSchedule_Click(object sender, EventArgs e)
    {
        string ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\A2 Computing\C# Programming Project\TriHard.accdb";
        string SelectQuery = "SELECT Time.AthleteID, Athlete.AthleteName, Time.EventTime, Event.EventDistance FROM Event INNER JOIN (Athlete INNER JOIN [Time] ON Athlete.[AthleteID] = Time.[AthleteID]) ON Event.[EventID] = Time.[EventID];";
        OleDbConnection Connection = new OleDbConnection(ConnectionString);
        OleDbCommand Command = new OleDbCommand(SelectQuery, Connection);
        Command.Connection.Open();

        OleDbDataReader Reader = Command.ExecuteReader(CommandBehavior.CloseConnection);

        PaceCalculator pace = new PaceCalculator();

        List<int> Distancelist = new List<int>();
        List<int> Secondslist = new List<int>();
        List<int> Pacelist = new List<int>();
        while (Reader.Read())
        {
            pace = new PaceCalculator();
            pace.Distance = (int)Reader["EventDistance"];
            int DistanceInt = Convert.ToInt32(pace.Distance);
            Distancelist.Add(DistanceInt);

            pace = new PaceCalculator();
            pace.Time = (string)Reader["EventTime"]; //Reads in EventTime
            double Seconds = TimeSpan.Parse(pace.Time).TotalSeconds; //Converts the string into HH:MM:SS as a double
            int SecondsInt = Convert.ToInt32(Seconds); //Converts the double into an integer, returning the seconds in the total time
            Secondslist.Add(SecondsInt); //Adds the Seconds for each time to the list;

            //Need to fix this currently returns just 0
            var Pacelist2 = PaceCalc(Distancelist, Secondslist);
            listBox3.DisplayMember = "PaceInt";
            listBox3.DataSource = (Pacelist2);



        }


        listBox1.DisplayMember = "DistanceInt";
        listBox1.DataSource = Distancelist;

        listBox2.DisplayMember = "SecondsInt";
        listBox2.DataSource = Secondslist;

这是我正在调用的函数，它试图划分列表，但似乎不起作用：

public List<int> PaceCalc(List<int> Dlist, List<int> Slist)
    {
        PaceCalculator pace = new PaceCalculator();
        List<int> Plist = new List<int>();

        pace = new PaceCalculator();
        for (int i = 0; i == Dlist.Count; i++)
        {
            int PaceInt = Dlist[i] / Slist[i];
            Plist.Add(PaceInt);
        }
        return Plist;
    }

我想在listBox3中显示除法的结果。我是否正确划分列表以及如何在列表框中显示它？

Answer 1

您的 for 循环永远不会执行，因为您正在测试 i == Dlist.Count。应该是：

for (int i = 0;i < Dlist.Count; i++)

或者，您可以使用 LINQ 执行此操作：

public List<int> PaceCalc(List<int> Dlist, List<int> Slist)
{
    return Dlist.Zip(Slist, (a, b) => a / b).ToList();
}

Answer 2

几个问题：

首先，您需要将签入 for 循环修改为 i < Dlist.Count。您当前的检查 i == Dlist.Count 是错误的。

所以你的方法是：

public List<int> PaceCalc(List<int> Dlist, List<int> Slist)
{
    List<int> Plist = new List<int>();
    for (int i = 0; i < Dlist.Count; i++)
    {
        int PaceInt = Dlist[i] / Slist[i];
        Plist.Add(PaceInt);
    }
    return Plist;
}

（我已经删除了 PaceCalculator pace = new PaceCalculator();，因为您的方法中根本不需要它）

其次。您不必为 ListBox3

指定 DisplayMember

var Pacelist2 = PaceCalc(Distancelist, Secondslist);
listBox3.DataSource = Pacelist2;

尽管第二个问题不会导致任何 error/exception，因为找不到 DisplayMember，它将使用默认的 ToString 重载，您将得到号码.

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