如何从通用列表中删除项目

时间:2011-02-04 23:22:50

标签: c# list generics

我有一个通用列表

如何删除项目?

EX:

Class Student
{
    private number;
    public Number
    {
        get( return number;)
        set( number = value;)
    }

    private name;
    public Name
    {
        get( return name;)
        set( name = value;)
    }

    main()
    {
        static List<student> = new list<student>();

        list.remove...???
    }
}

9 个答案:

答案 0 :(得分:24)

好吧,没有什么可以删除,因为你的列表是空的(你也没有给它一个标识符,因此你的代码将无法编译)。您可以使用Remove(T item)RemoveAt(int index)分别删除指定索引处的对象或对象(一旦实际包含某些内容)。

受控代码示例:

void Main(...)
{
    var list = new List<Student>();
    Student s = new Student(...);
    list.Add(s);

    list.Remove(s); //removes 's' if it is in the list based on the result of the .Equals method

    list.RemoveAt(0); //removes the item at index 0, use the first example if possible/appropriate
}

答案 1 :(得分:17)


根据您的意见,我得出结论,您从输入中读取了学生姓名,您需要删除具有指定姓名的学生。

class Student {
    public string Name { get; set; }
    public int Number { get; set; }

    public Student (string name, int number)
    {
        Name = name;
        Number = number;
    }
}


var students = new List<Student> {
    new Student ("Daniel", 10),
    new Student ("Mike", 20),
    new Student ("Ashley", 42)
};

var nameToRemove = Console.ReadLine ();
students.RemoveAll (s => s.Name == nameToRemove); // remove by condition

请注意,这将删除所有具有指定姓名的学生。

如果您需要删除按名称找到的第一个学生,请先使用First方法找到他,然后为该实例调用Remove

var firstMatch = students.First (s => s.Name == nameToRemove);
students.Remove (firstMatch);

如果您想要在删除之前确保只有一个学生具有指定名称,请以类似的方式使用Single

var onlyMatch = students.Single (s => s.Name == nameToRemove);
students.Remove (onlyMatch);

请注意Single如果没有一个项与谓词匹配,则会失败

答案 2 :(得分:3)

List<Student> students = new List<Student>();
students.Add(new Student {StudentId = 1, StudentName = "Bob",});
students.RemoveAt(0); //Removes the 1st element, will crash if there are no entries

或删除已知学生。

//Find a Single Student in the List.
Student s = students.Where(s => s.StudentId == myStudentId).Single();
//Remove that student from the list.
students.Remove(s);

答案 3 :(得分:1)

好吧,你没有给你的名单一个名字,你的一些语法很难。

void main()
{
   static List<Student> studentList = new List<Student>();
}

// later
void deleteFromStudents(Student studentToDelete)
{
   studentList.Remove(studentToDelete);
}

此处详细介绍了更多删除功能:C# List Remove Methods

答案 4 :(得分:1)

int count = queue.Count;

        while(count>0)
        {
            HttpQueueItem item = queue[0];
            /// If post succeeded..
            if (snd.IsNotExceedsAcceptedLeadsPerDayLimit(item.DataSaleID, item.AcceptedLeadsPerDayLimit) && snd.PostRecord(item.DataSaleDetailID, item.PostString, item.duplicateCheckHours, item.Username, item.Password, item.successRegex))
            {
                if (item.WaitTime > 0)
                    Thread.Sleep(item.WaitTime);
                queue.Remove(item);
            }
                ///If Exceeds Accepted leads per day limit by DataSale..
            else if (!snd.IsNotExceedsAcceptedLeadsPerDayLimit(item.DataSaleID, item.AcceptedLeadsPerDayLimit))
            {
                queue.RemoveAll(obj => obj.DataSaleID == item.DataSaleID);
            }
                /// If Post failed..
            else //if (!snd.PostRecord(item.DataSaleDetailID, item.PostString, item.duplicateCheckHours, item.Username, item.Password, item.successRegex))
            {
                queue.Remove(item);
            }
            count = queue.Count;
        }

答案 5 :(得分:1)

要从网格视图中的通用列表中删除行或记录,只需编写此代码 -

List<Address> people = new List<Address>();
Address t = new Address();
people.RemoveAt(e.RowIndex);
grdShow.EditIndex = -1;
grdShow.DataSource = people;
grdShow.DataBind();

答案 6 :(得分:0)

也许您可以使用Dictionary<string, Student>代替List<Student>

添加学生时,请添加其ID或名称或任何可以唯一标识的名称。然后,您只需拨打myStudents.Remove(myStudentId)

即可

答案 7 :(得分:0)

尝试linq:

  var _resultList = list.Where(a=>a.Name != nameToRemove).Select(a=>a);

答案 8 :(得分:0)

我制作了一个包含7张卡的程序,然后随机播放,我希望能够帮助他们

class Program
{

    static void Main(string[] args)
    {
        Random random = new Random(); 
        var cards = new List<string>();
        //CARDS VECRTOR
        String[] listas = new String[] { "Card 1", "Card 2", "Card 3", "Card 4", "Card 5", "Card 6", "Card 7"};


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

            int number = random.Next(0, 7); //Random number 0--->7


            for (int j = 0; j <=6; j++)
            {
                if (cards.Contains(listas[number])) // NO REPEAT SHUFFLE
                {

                    number = random.Next(0, 7); //AGAIN RANDOM

                }
                else
                {
                    cards.Add(listas[number]); //ADD CARD
                }
            }

        }

        Console.WriteLine(" LIST CARDS");

        foreach (var card in cards)
        {
            Console.Write(card + " ,");


        }

        Console.WriteLine("Total Cards: "+cards.Count);

        //REMOVE

        for (int k = 0; k <=6; k++)
        {
           // salmons.RemoveAt(k);
            Console.WriteLine("I take the card: "+cards.ElementAt(k));
            cards.RemoveAt(k); //REMOVE CARD
            cards.Insert(k,"Card Taken"); //REPLACE INDEX
            foreach (var card in cards)
            {
                Console.Write(card + " " + "\n");

            }


        }


        Console.Read(); //just pause

    }



}