CODEWITHSUNDEEP
c#
Oleg Vazhnev
Oleg Vazhnev

Reputation: 24067

how to convert List<SomeType> to List<AnotherType>?

I have two data types:

class MyDataType {
    public int Id;
    private int Field;
    public String AnotherFieldOrProperty;
    // + there are some methods
}

class MyDataTypeDescriptor {
    public int Id;
    public String Description;
}

I need to convert List<MyDataType> to List<MyDataTypeDescriptor> such a way: MyDataTypeDescriptor.Id = MyDataType.Id MyDataTypeDescriptor.Description = MyDataType.ToString();

I guess C# can do that very easy and fast in just one line of code, but I don't know how because I'm not familar with such advanced techniques. Would someone help me please?

Thanks

Upvotes: 2

Views: 137

Answers (8)

Pharabus
Pharabus

Reputation: 6062

Just to add one more way

define an explicit user type conversion MSDN

then do

var newlist = MyDataTypleList.Cast<MyDataTypeDescriptor>().ToList();

Upvotes: 0

Erix
Erix

Reputation: 7105

You can't actually convert them, you'll have to iterate through the collection and create a new Descriptor for each DataType

var result = (from MyDataType m in listOfMyDataType select new MyDataTypeDescriptor
{
   Id = m.Id,
   Description = m.toString(),
}).ToList();

Upvotes: 0

Nathan Anderson
Nathan Anderson

Reputation: 6878

You can do this with LINQ:

var listofMyDataTypeDescriptor = (from m in listOfMyDataType
                                 select new MyDataTypeDescriptor()
                                 {
                                     Id = m.Id,
                                     Description = m.ToString()
                                 }).ToList();

Upvotes: 0

James Johnson
James Johnson

Reputation: 46047

For simple conversions, you can use the Select method like this:

List<int> lstA = new List<int>();
List<string> lstB = lstA.Select(x => x.ToString()).ToList();

For more compex conversions, you the ConvertAll function, like this:

List<int> lstA = new List<int>();
List<string> lstB = lstA.ConvertAll<string>(new Converter<int, string>(StringToInt));

public static string StringToInt(int value)
{
    return value.ToString();
}

Upvotes: 0

Otiel
Otiel

Reputation: 18743

You can do it by using LINQ Select method:

List<MyDataType> list;
// Process list...
List<MyDataTypeDescriptor> result = 
    list.Select(x => new MyDataTypeDescriptor() { Id = x.Id, Description = x.ToString() }).
         ToList<MyDataTypeDescriptor>();

Or if you have a constructor for MyDataTypeDescriptor that takes an Id and a Description:

List<MyDataType> list;
// Process list...
List<MyDataTypeDescriptor> result = 
    list.Select(x => new MyDataTypeDescriptor(x.Id, x.ToString())).
         ToList<MyDataTypeDescriptor>();

Upvotes: 0

XeroxDucati
XeroxDucati

Reputation: 5190

You can use automapper to do this automagically for you if you don't want to write the iterator yourself..

Upvotes: 0

Richard Dalton
Richard Dalton

Reputation: 35793

This should do it (where myDataTypes is your List<MyDataType>):

List<MyDataTypeDescriptor> myDataTypeDescriptors = 
     myDataTypes.Select(x => new MyDataTypeDescriptor 
                                 { 
                                      Id = x.Id, 
                                      Description = x.ToString() 
                                 }).ToList();

Upvotes: 4

drdwilcox
drdwilcox

Reputation: 3951

(from i in list1 
 select new MyDataTypeDescriptor { Id = i.Id, Description = i.ToString()).ToList();

Upvotes: 0

Related Questions