CODEWITHSUNDEEP
c#sqllinqwcf
Peter
Peter

Reputation: 761

Cannot implicitly convert type 'bool' to 'system.threading.tasks.task bool'

I have this error: "Cannot implicitly convert type 'bool' to 'system.threading.tasks.task bool'" in my service implementation code. Could you correct my code please. 

public Task<bool> login(string usn, string pwd)
    {
        DataClasses1DataContext auth = new DataClasses1DataContext();
        var message = from p in auth.Users
                      where p.usrName == usn && p.usrPass == pwd
                      select p;
        if (message.Count() > 0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

Upvotes: 34

Views: 76959

Answers (2)

toddmo
toddmo

Reputation: 22406

If you add Task.FromResult, you can fake it into compiling and working even though your method is not async. I had to do this when hooking up Identity, which is all async, to a legacy back end.

Example:

public override Task<bool> IsEmailConfirmedAsync(string userId)
{
  var profile = UserProfileType.FetchUserProfile(AtlasBusinessObject.ClientId.ToString(), decimal.Parse(userId));
  Task.FromResult(profile.EmailAddress.NullIfEmpty() != null);
}

Upvotes: 19

Ramy M. Mousa
Ramy M. Mousa

Reputation: 5933

You need to be specific whether you want this operation happen asynchronously or not.

As an example for Async Operation :

public async Task<bool> login(string usn, string pwd)
{
    DataClasses1DataContext auth = new DataClasses1DataContext();
    var message = await (from p in auth.Users
                  where p.usrName == usn && p.usrPass == pwd
                  select p);
    if (message.Count() > 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

If you don't need it to be an Async operation, try this: 

public bool login(string usn, string pwd)
{
    DataClasses1DataContext auth = new DataClasses1DataContext();
    var message = from p in auth.Users
                  where p.usrName == usn && p.usrPass == pwd
                  select p;
    if (message.Count() > 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

Note: async and await are compatible with .net 4.5 and C# 5.0 and more

Upvotes: 31

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