CODEWITHSUNDEEP
asp.net-coreasynchronous.net-coreasp.net-core-mvc
John John
John John

Reputation: 1

Can not use await + Result.Error:- 'string' does not contain a definition for 'GetAwaiter' and no accessible extension method 'GetAwaiter'

I have the following code inside my asp.net core mvc:-

var result = await _context.Settings.SingleOrDefaultAsync(a => a.Name.ToLower() == "noofvisits").Result.Value;

but i got this error:-

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

so why i am getting this error? Thanks

Upvotes: 0

Views: 567

Answers (2)

Rena
Rena

Reputation: 36755

If you want to get the single object,using:

var result = await _context.Settings
                           .SingleOrDefaultAsync(a => a.Name.ToLower() == "noofvisits");

If you want to get the single property in the object,using:

var result = await _context.Settings.Where(a => a.Name.ToLower() == "noofvisits")
                                    .Select(s => s.PropertyName).FirstOrDefaultAsync();

Upvotes: 1

Adam
Adam

Reputation: 3877

You are specifying an await for an asynchronous call that you are subsequently blocking on the result for. By adding .Result, your code is now acting synchronously, returning a string and not a Task that can be awaited, which is what the await keyword is meant for.

The return type of SingleOrDefaultAsync() is a Task<T> where T is whatever data type that is supposed to return. With the await, you are telling your code "Hey, whenever that task finishes and gives me a result, I'm waiting for that result".

If the expected data type is already a string, you don't have to do anything, you'd get a string back by doing:

string result = await _context.Settings.SingleOrDefaultAsync(a => a.Name.ToLower() == "noofvisits");

If it's a more complex POCO or something you need to grab a string from synchronously after you get the result, then you can do so after the task has finished:

var result  = await _context.Settings.SingleOrDefaultAsync(a => a.Name.ToLower() == "noofvisits");
string yourString = result.DoWhateverHere();

Upvotes: 2

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