How to Update an item in a list by LINQ

Question

I have a list of class objects.This Class object comprise of 3 string properties.Using LINQ i am able to query the list, now i want to update one of the properties of any class objects Any help will be highly appreciated.Thanks

anil babu · Answer

List empList = new List { new Employee() { EmpNo=101,EmpName= "Anil" , AllDepart= new List { new Department () { DeptNo=1,Dname= "Sales" ,Location= "Vij" } }, DeptName= "DEV" , AllSales= new List { new Sales () { SName= "jjj" ,Sloc= "ban" , Orders= new List { new Order (){Oid=200,OName= "ebay" } } } }, Purchages= new List { new Purchage () { Id=200,IName= "Mobiles" } //new Department () { DeptNo=2,Dname= "DEv" ,Location= "Gun" }, //new Department () { DeptNo=3,Dname= "pro" ,Location= "Ong" } } } }; } public static class LinqUpdates { public static void Update ( this IEnumerable source, Action action) { foreach (var item in source) action(item); } } } I want to update the above list using the below methods how? I am trying this way not possible Method is public void Update(Employee obj) { var list = loadList; loadList.Where(p => p.EmpNo == obj.EmpNo).Update(); } how to modify my method?

Subhendu De · Answer

Yes you can but you need to write the extension method for it. Dont worry, Troy Magennis had written it. I used that extension method. The link is http://www.hookedonlinq.com/UpdateOperator.ashx Please go through the code. If you need any other info, please let me know. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq; using System.IO; using System.Threading; using System.Data.SqlClient; namespace PracticeConsole { class Program { static void Main( string [] args) { Student[] _arrStudents = new Student[] { new Student( "AAA" , "1" , "A" ), new Student( "BBB" , "2" , "B" ), new Student( "CCC" , "3" , "C" ), new Student( "DDD" , "4" , "D" ), new Student( "EEE" , "5" , "E" ), new Student( "FFF" , "6" , "F" ), new Student( "GGG" , "7" , "G" ), new Student( "HHH" , "8" , "H" ), new Student( "III" , "9" , "I" ) }; Console.WriteLine( "Before update" ); foreach (Student _student in _arrStudents) { Console.WriteLine(String.Format( "{0},{1},{2}" , _student.Name, _student.Standard, _student.Status)); } var query = (from stud in _arrStudents where stud.Name == "BBB" select stud) .Update(st => { st.Standard = "0" ; st.Status = "X" ; }); Console.WriteLine( "After update" ); foreach (Student _student in _arrStudents) { Console.WriteLine(String.Format( "{0},{1},{2}" ,_student.Name,_student.Standard,_student.Status)); } } } class Student { public string Name { get ; set ; } public string Standard { get ; set ; } public string Status { get ; set ; } public Student( string name, string standard, string status) { this .Name = name; this .Standard = standard; this .Status = status; } } public static class UpdateExtensions { public delegate void Func (TArg0 element); public static int Update ( this IEnumerable source, Func update) { if (source == null ) throw new ArgumentNullException( "source" ); if (update == null ) throw new ArgumentNullException( "update" ); if ( typeof (TSource).IsValueType) throw new NotSupportedException( "value type elements are not supported by update." ); int count = 0; foreach (TSource element in source) { update(element); count++; } return count; } } }

How to Update an item in a list by LINQ

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