Asp.Net GridView Associates Custom Object with Nested List

Question

I have a list of user objects that consist of a user list.

class person{
  string name;
  int age;
  List<friend> allMyFriends;
}

class friend{
  string name;
  string address;
}

I am going to associate a list of these objects with a GridView, and the Grid should create a column for each friend and write a name in it. If some people have the same boundaries, the grid should not create a separate column, but use an existing one. If you know what I mean. (Classes are just some examples of classes to simplify my case)

Is there a way to dynamically adjust the binding?

I can change class definitions etc. if they need to inherit from some interfaces or so on.

I googled a lot, but not a single example really covered this case.

Can using objectSourceControl somehow solve my problem?

:

: , .

List<person> allPerson = new List<person>();
// fill the list
Grid.DataSource = allPerson;
Grid.DataBind()

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friend1 friend2
   x              peter
   x       x      adam

RowDataBound, , , my . List person .

Answer 1

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public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // setup your person object with static data for testing
        List<person> allPerson = new List<person>()
        {
            new person() 
            { 
                name = "Dan", 
                age = 21, 
                allMyFriends = new List<friend>() { new friend("James"), new friend("John"), new friend("Matt") } 
            }, 
            new person() 
            { 
                name = "James", 
                age = 21, 
                allMyFriends = new List<friend>() { new friend("Dan"), new friend("Matt"), new friend("Tom") } 
            }, 
            new person() 
            { 
                name = "John", 
                age = 21, 
                allMyFriends = new List<friend>() { new friend("Dan") } 
            }, 
            new person() 
            { 
                name = "Matt", 
                age = 21, 
                allMyFriends = new List<friend>() { new friend("Dan"), new friend("James") } 
            }, 
            new person() 
            { 
                name = "Tom", 
                age = 21, 
                allMyFriends = new List<friend>() { new friend("James") } 
            }
        };

        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.Add("Name");
        dt.Columns.Add("Age");

        foreach (person p in allPerson)
        {
            // step through each person and look at their friends
            foreach (friend f in p.allMyFriends)
            {
                // look to see if this friend has a column already
                if (!dt.Columns.Contains(f.name))
                {
                    dt.Columns.Add(f.name);
                }
            }
        }

        foreach (person p in allPerson)
        {
            // create the datarow that represents the person
            System.Data.DataRow dr = dt.NewRow();
            dr["Name"] = p.name;
            dr["Age"] = p.age;

            // find the friends and mark them
            foreach (friend f in p.allMyFriends)
            {
                dr[f.name] = "X";
            }

            dt.Rows.Add(dr);
        }

        // fill the list
        this.Grid.DataSource = dt;
        this.Grid.DataBind();

    }
}

public class person
{
    public string name;
    public int age;
    public List<friend> allMyFriends = new List<friend>();
}

public class friend
{
    public string name;
    public string address;

    public friend()
    {

    }

    public friend(string name)
    {
        this.name = name;
    }

    public friend(string name, string address)
    {
        this.name = name;
        this.address = address;
    }
}

: , .

-------------------------------------------------
| Name  | Age | James | John | Matt | Dan | Tom |
-------------------------------------------------
| Dan   | 21  | X     | X    | X    |     |     |
| James | 21  |       |      | X    | X   | X   |
| John  | 21  |       |      |      | X   |     |
| Matt  | 21  | X     |      |      | X   |     |
| Tom   | 21  | X     |      |      |     |     |
-------------------------------------------------   

Answer 2

, /- GridView. , , . -, SQL-.

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, ...

Answer 3

Take a look at my answer to a similar "nested binding" question here .

Answer 4

You can also simply use the RowDataBound event handler to perform complex bindings.

Answer 5

use the following:

DataBinder.Eval (Container.DataItem, "PPP.PPP")