在C＃中使用Web服务-List

Question

score#UPDATED# This probably sounds pretty dumb but I've been stuck on this problem for three days now! I am new to C#.

I am trying to consume a web service in C#. I managed to consume the web service in Java with the following lines of code:

            List x = new ArrayList<Score>();

            x = topScores();

            System.out.println("x" + x.size());

            System.out.println("TOP SCORES:");
            for (Object o : x) {
                Score s1 = (Score) o;
                System.out.println(s1.getScore());

            }

I need to display a list of scores but can't seem to figure it out in C#. Here is where I am stuck in C#:

           List<object[]> list = new List<score[]>();

I have tried loads of different variations of declaring collections but can't get past this. I think I know how to iterate through a list but I can't get past declaring it. Here is my error message:

Cannot implicitly convert type `System.Collections.Generic.List<score>' to `System.Collections.Generic.List<object>'

If I change the declaration to :

List<score> list = new List<score>();
list = service.TopScores();

I get the same error but this time I get a message saying:

"Object[] TopScores()"

What is the C# equivalent of my Java snippet? I'd really appreciate any help or suggestions! Thank you for your time!

Answer 1

The List<> class is in a category of collections called Generics, which allows you to create an array of strongly-typed objects. . The List part implies an array, so you don't need to declare the type as an array as well. Instead of List<object[]> , you should just do List<object> . You also can't change the data type of the list. If you want to create a list of Score you should just do.

List<Score> scores = new List<Score>();

then you could populate the list with scores like

Score newScore = new Score();
scores.Add(newScore); 

or whatever

Answer 2

Thank you for your help...I figured it out...

        LoginService service = new LoginService();
        List<score> listA = new List<score>();

        object[] array = listA.ToArray();
        array = service.TopScores();

Answer 3

It looks like you don't need to create a List<object> because your code always knows that the elements of the list are of type Score . You can do this instead

List<Score> list = new List<Score>(); // Not really necessary because you assign it a different value in the next line.

list = topScores().Select(o => o.ToString()).ToList();

...

System.Console.WriteLine("x{0}", list.Length);

System.Console.WriteLine("TOP SCORES:");
foreach (var score in list) {
    System.Console.WriteLine(score.GetScore());
}

However if you really want to create a List<object> from a List<string> the easiest way to do that is this:

List<string> stringList = ...
List<object> objectList = stringList.ToList<object>();

Answer 4

You need to have the same type when declaring this list.

List<score> list = new List<score>();

then

    foreach(Score score in list)
    {
    //do something
    }