Question

我正在为此寻找一个LINQ删除方法：

<ArrayOfGroup>
    <Group>
        <GroupName>c</GroupName>
        <StudentList>
             <Student>
                 <TimeAdded>0001-01-01T00:00:00</TimeAdded> // trying to delete from here
                 <StudentID>1</StudentID>
                 <FirstName>a</FirstName>
                 <LastName>b</LastName> // to here
                 <StudentGroup/>
             </Student>
        </StudentList>
    </Group>
</ArrayOfGroup>

出于某种原因我以这种方式删除它：

[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)] 
public class Service : IService
{
    List<Student> students = new List<Student>();
    List<Group> Groups = new List<Group>();
    public void removeStudent(string studentID)
    {
        students.Remove(students.Find(f => f.StudentID.Equals(studentID)));
        //var result = students.Where(n => String.Equals(n.StudentID, studentID)).FirstOrDefault();
        //if (result == null)
        //{
        //    result.StudentGroup.Remove(StudentList.Student.Find(f => f.StudentID.Equals(studentID)));
        //}
        // students.RemoveAll(f => f.StudentID.Equals(studentID)); also tryed this
    }

它不会将它从我的ArrayOfGroup的学生列表/学生区域中删除，所以我厌倦了试图解决它为什么不删除而只是试图找到一种新方法将其与原始记录一起删除。我觉得这样做是犯罪但是如果有人可以帮助我会非常感激。

我的数据合约如下所示：

[DataContract(Name="Student")]
public class Student
{
    public Student()
    {
        StudentGroup = new List<Group>();
    }

    [DataMember(Name = "StudentID")]
    public string StudentID { get; set; }

    [DataMember(Name = "FirstName")]
    public string FirstName { get; set; }

    [DataMember(Name = "LastName")]
    public string LastName { get; set; }

    [DataMember(Name = "TimeAdded")]
    public DateTime TimeAdded;

    public string TimeAddedString
    {
        get
        {
            return this.TimeAdded.ToString("dd/MM/yyyy hh:mm:ss");
        }
    }

    public List<Group> StudentGroup { get; set; }
}

[DataContract(Name = "Group")]
public class Group
{
    public Group() 
    {
        StudentList = new List<Student>();
    }

    [DataMember(Name = "GroupName")]
    public string GroupName { get; set; }

    public List<Student> StudentList { get; set; }
}

如果学生有帮助，这就是如何将学生添加到小组中？

public void AddStudentToGroup(string group, string studentID, string firstName, string lastName)
{
    var result = Groups.Where(n => String.Equals(n.GroupName, group)).FirstOrDefault();
    var result1 = students.Where(n => String.Equals(n.StudentID, studentID)).FirstOrDefault();
    if (result != null)
    {
        result.StudentList.Add(new Student() { StudentID = studentID, FirstName = firstName, LastName = lastName });
    }
    if (result1 != null)
    {
        result1.StudentGroup.Add(new Group() { GroupName = group });
    }
}

Answer 1

您可以在Remove对象上使用List<T>方法，该方法采用如下谓词：

students.RemoveAll(s => s.StudentId == 5);

在WCF中删除方法

1 个答案: