Task does not contain a definition for 'FirstOrDefault'

Question

Error CS1061 'Task>' does not contain a definition for 'FirstOrDefault' and no extension method 'FirstOrDefault' accepting a first argument of type 'Task>' could be found (are you missing a using directive or an assembly reference?) ,

making a web application with facebook controller, included using system.linq but still getting the error for FirstOrDefault(). I dont know what the problem is, i reinstalled visual studio too as he same thing works for my friends laptop. I juggled around to see if the method is present in the library and it is there but still not getting past this Image for the same

public async Task<ActionResult> Posts()
{
    var currentClaims = UserManager.GetClaimsAsync(HttpContext.Identity.GetUserId());

    // Error occurs here at FirstOrDefault
    var accesstoken = currentClaims.FirstOrDefault(x = > x.Type == "urn:tokens:facebook");

    if (accesstoken == null)
    ...
}

What is the type of the currentClaims variable ? To use FirstOrDefault the type must be IEnumerable. — Vasilut Lucian, Feb 18 '17 at 21:56

score 11 · Accepted Answer · answered Feb 18 '17 at 21:56

11

You are missing an await in front of UserManager.GetClaimsAsync():

var currentClaims = await UserManager.GetClaimsAsync(...);

answered Feb 18 '17 at 21:56

M4N

94,805
45
217
260

score 2 · Answer 2 · edited Sep 03 '18 at 12:33

Look closely at the error message. GetClaimsAsync returns type Task<IList<Claim>>, not type list. The Task type doesn't have a FirstOrDefault method. As other people have indicated, await GetClaimsAsync and it'll work.

As a side note, do not use .Result here as that will deadlock in most environments. See this article for an explanation of why this will deadlock as well as this article on async/await best practices.

Task does not contain a definition for 'FirstOrDefault'

2 Answers2

Linked

Related