如何将 List<int> 作为 List<T> 对象访问？

Question

对于这个新问题深表歉意，但我很难思考如何访问通用列表中的整数列表，然后将所有这些信息显示到列表视图 (winform) 中。这是我目前所拥有的...

    }
    List<Student> students;
    public class Student
    {

        public string First { get; set; }

        public string Last { get; set; }

        public List<int> Scores { get; set; }


        public int ID { get; set; }


        public string[] ToListViewItem()
        {
            return new string[] {
                First,
                Last,
                ID.ToString(),
                Scores.ToString()
            };

        }

    }

    protected override void OnLoad(EventArgs e)

    {
        base.OnLoad(e);

        students = new List<Student>


        {

        new Student {First="Svetlana", Last="Omelchenko", ID=111, Scores= new List<int> {97, 92, 81, 60}},

        new Student {First="Claire", Last="O’Donnell", ID=112, Scores= new List<int> {75, 84, 91, 39}},

        new Student {First="Sven", Last="Mortensen", ID=113, Scores= new List<int> {88, 94, 65, 91}},

        new Student {First="Cesar", Last="Garcia", ID=114, Scores= new List<int> {97, 89, 85, 82}},

        new Student {First="Debra", Last="Garcia", ID=115, Scores= new List<int> {35, 72, 91, 70}},

        new Student {First="Fadi", Last="Fakhouri", ID=116, Scores= new List<int> {99, 86, 90, 94}},

        new Student {First="Hanying", Last="Feng", ID=117, Scores= new List<int> {93, 92, 80, 87}},

        new Student {First="Hugo", Last="Garcia", ID=118, Scores= new List<int> {92, 90, 83, 78}},

        new Student {First="Lance", Last="Tucker", ID=119, Scores= new List<int> {68, 79, 88, 92}},

        new Student {First="Terry", Last="Adams", ID=120, Scores= new List<int> {99, 82, 81, 79}},

        new Student {First="Eugene", Last="Zabokritski", ID=121, Scores= new List<int> {96, 85, 91, 60}},

        new Student {First="Michael", Last="Tucker", ID=122, Scores= new List<int> {94, 92, 91, 91} }


    };

        PopulateListView(students);


        GetAverageGrade();

    }

    public void GetAverageGrade()
    {
        foreach (Student s in students)
        {
            double avg = s.Scores.Average();


        }

    }

    public void PopulateListView(List<Student> list)
    {

        listView1.SuspendLayout();

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

            // create a list view item
            var lvi = new ListViewItem(list[i].ToListViewItem());
            // assign class reference to lvi Tag for later use
            lvi.Tag = list[i];
            // add to list view
            listView1.Items.Add(lvi);

            //This adjust the width of 1st column to fit data.
            listView1.AutoResizeColumn(0, ColumnHeaderAutoResizeStyle.ColumnContent);
            listView1.ResumeLayout();
        }


    }
}

到目前为止，我能够让我的列表视图的前三列填充姓名和学生 ID，但我在最后一列中得到的只是 "Systems.Collections.Generic..."，等等。

非常感谢任何帮助，谢谢。

Answer 1

您可能正在使用 Scores.ToString() 方法，其中 returns 类名。您可以尝试： string.Join(", ", Scores) 代替。这将连接所有用 ,.

分隔的值

public string[] ToListViewItem()
{
    return new string[] {
        First,
        Last,
        ID.ToString(),
        string.Join(", ", Scores)
    };
}

Answer 2

就是这样 Scores.ToString() returns.

如果你想显示有用的信息，你需要编写消耗你的 List<int> 和 returns 有用信息的代码。

首先查看 string.Join()。

如何将 List<int> 作为 List<T> 对象访问？

How would one access a List<int> as a List<T> object?

c#

listview

nested-lists

listviewitem

winforms