c# - Converting dynamic into Lambda expression

Coding Platform: ASP.NET C# 4.0

I have the following snippet

public string PageID { get { return "20954654402"; } }
dynamic accounts = fb.Get("me/accounts");
if (accounts != null)
{
    bool isFound = false;
    foreach (dynamic account in accounts.data)
    {
        if (account.id == PageID)
        {
            isFound = true;
            break;
        }
    }
    if (!isFound)
    {
        //  user not admin
    }
    else
    {

    }
}

Two questions

1. Why does (account.id == PageID) errors (PageID is a string property) Update: That was a stupid unrelated error as I as calling all of these at PageMethods.
2. Is there a simpler and more C#4.0 like way to change the foreach loop?

Update:

Its the response from a call to Facebook API. A sample will be

{
    [{
        "name": "Codoons",
        开发者_JAVA百科"category": "Computers/technology",
        "id": "20954694402",
        "access_token": "179946368724329|-100002186424305|209546559074402|Hp6Ee-wFX9TEQ6AoEtng0D0my70"
    }, {
        "name": "Codtions Demo Application",
        "category": "Application",
        "id": "1799464329",
        "access_token": "179946368724329|-100002186424305|179946368724329|5KoXNOd7K9Ygdw7AMMEjE28_fAQ"
    }, {
        "name": "Naen's Demo Application",
        "category": "Application",
        "id": "192419846",
        "access_token": "179946368724329|61951d4bd5d346c6cefdd4c0.1-100002186424305|192328104139846|oS-ip8gd_1iEL9YR8khgrndIqQk"
    }]
}

Updated code also a little bit.

The intention is to get the account.id that matches with PageID and get the access_token associated with that account.id

Thank you for your time.

You can use the LINQ methods for an alternative to the foreach:

if(accounts.Any(a => a.id == PageID))
{
    //  user not admin
}
else
{

}

As to why it "errors": We can't say that, because we don't know what type id is of. But if id is of type int, this would explain an error.

If the accounts collection can be modified (inserts, deletes) on another thread foreach will throw an exception when that happens (simple for loop won't).

When using == with a string i.e. PageID is a string, then the account.id should also be a string, not an int or float, maybe thats whats causing the error

accounts.data.Any(a => a.id.ToString() == PageID)

You should use a dynamic predicate. Something like this:

var pagesWithId = (Predicate)((dynamic x) => x.id == PageId);
var pagesFound = accounts.FindAll(pagesWithId);

if(pagesFounds.Count() > 0)
 //do your thing