How to Convert List to ObservableCollection?

Question

I am a java Developer,new to C# silverlight. in this class I want to Convert the Products(List) to ObservableCollection.

    using System;
    using System.Collections.Generic;
    using System.Collections.ObjectModel;
    using System.Linq;

namespace WPListBoxImage
{
/**It seems not work,if I just change List<Product> to ObservableCollection<Product>
  public class Products : List<Product>
  {
    public Products()
    {
      BuildCollection();

    }

    private const string IMG_PATH = "../Images/";

    public ObservableCollection<Product> DataCollection { get; set; }

    public ObservableCollection<Product> BuildCollection()
    {
      DataCollection = new ObservableCollection<Product>();

      DataCollection.Add(new Product("Haystack Code Generator for .NET", 799, IMG_PATH + "Haystack.jpg"));
      DataCollection.Add(new Product("Fundamentals of N-Tier eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundNTier_100.jpg"));
      DataCollection.Add(new Product("Fundamentals of ASP.NET Security eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundSecurity_100.jpg"));
      DataCollection.Add(new Product("Fundamentals of SQL Server eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundSQL_100.jpg"));
      DataCollection.Add(new Product("Fundamentals of VB.NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundVBNet_100.jpg"));
      DataCollection.Add(new Product("Fundamentals of .NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "FundDotNet_100.jpg"));
      DataCollection.Add(new Product("Architecting ASP.NET eBook", Convert.ToDecimal(19.95), IMG_PATH + "ArchASPNET_100.jpg"));
      DataCollection.Add(new Product("PDSA .NET Productivity Framework", Convert.ToDecimal(2500), IMG_PATH + "framework.jpg"));

      return DataCollection;
    }
  }
}

what should I do to fix it? or need to create a new class?

Solution 1

Your Products class shouldn't inherit anything.

public class Products

Accessing all the items in your collection is done through the DataCollection property of the Product class. For example,

Products myProducts = new Products();
ObservableCollection<Product> myData = myProducts.DataCollection;

It also depends on how you want to use Products. You may be able to totally do away with this class and then do something like:

ObservableCollection<Product> Products = new ObservableCollection<Product>();
Products.Add(new Product("Haystack Code Generator for .NET", 799, IMG_PATH + "Haystack.jpg"));
// etc...

Solution 2

There is a constructor in ObservableCollection that does this:

ObservableCollection<T> oc = new ObservableCollection<T>(List<T> list);

Solution 3

You can make a extension method that will let you convert any type of List into an ObservableCollection easily.

public static class CollectionUtils
{
    public static ObservableCollection<T> ToObservableCollection<T>(this IEnumerable<T> thisCollection)
    {
        if (thisCollection == null) return null;
        var oc = new ObservableCollection<T>();

        foreach (var item in thisCollection)
        {
            oc.Add(item);
        }

        return oc;
    }
}

For example:

Products p = new Products();
//add your products

var collection = p.ToObservableCollection(); //use the extension method.

Solution 4

The class Products is a list. In BuildCollection you access this with the Add method. You don't need an auxiliary structure in my opinion.

To convert list to ObservableCollection use

this.Select<Product, ObservableCollection>(p  => p) 

method on collection.

View more solutions

Comments

[Albert.Qing]

You're genius! Indeed,I've been confused for this question yestoday.but can't find solution until now.Do you mind go to this link,and Paste this answer for someone had some problem ,I'll mark the answer.

[William Melani]

just noticed this wasn't actually returning an ObservableCollection. updated