单击按钮时只有两个列表框之一被填充

Question

我正在尝试使用从数据库中读取的两个不同列表来填充两个列表框。这是我的代码：

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<PaceCalculator> Distancelist = new List<PaceCalculator>();
        while (Reader.Read())
        {
            pace = new PaceCalculator();
            pace.Distance = (int)Reader["EventDistance"];
            Distancelist.Add(pace);
        }


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

        List<PaceCalculator> TimeList = new List<PaceCalculator>();
        while (Reader.Read())
        {
            pace = new PaceCalculator();
            pace.Time = (string)Reader["EventTime"];
            TimeList.Add(pace);
        }

        listBox2.DisplayMember = "Time";
        listBox2.DataSource = TimeList;






    }

当我按下按钮时，listBox1 被填充，但 listBox2 没有。我该如何解决这个问题，使两个框彼此相邻填充？

Answer 1

OleDbDataReader 提供了一种仅以转发模式从基础数据库中读取数据的方法。所以，当你到达循环的末尾时，你不能重新启动它希望从你的数据的 init 再次读取。
因此，只需从数据源中读取距离和时间值并将它们添加到单个 PaceCalculator 对象实例并将其添加到列表中即可。所有这些都在一个循环中。

退出循环时，只需将列表框的数据源设置为两个不同的列表并设置不同的 DisplayMember 属性

    List<PaceCalculator> TimeList = new List<PaceCalculator>();
    List<PaceCalculator> Distancelist = new List<PaceCalculator>();
    while (Reader.Read())
    {
        pace = new PaceCalculator();
        pace.Distance = (int)Reader["EventDistance"];
        pace.Time = (string)Reader["EventTime"];
        Distancelist.Add(pace);
        TimeList.Add(pace);
    }

    listBox1.DisplayMember = "Distance";
    listBox1.DataSource = Distancelist;
    listBox2.DisplayMember = "Time";
    listBox2.DataSource = TimeList;

单击按钮时只有两个列表框之一被填充

Only one of two listbox is being populated on the button click

c#

listbox

list