Is it possible to use Task in if conditions?

问题:

In Windows Phone 8 I have method public async Task<bool> authentication(). The return type of the function is bool but when I tried to use its returned value in a if condition error says can not convert Task<bool> to bool.

public async Task<bool> authentication()
{
    var pairs = new List<KeyValuePair<string, string>>
    {
        new KeyValuePair<string, string> ("user", _username),
        new KeyValuePair<string, string> ("password", _password)
    };

    var serverData = serverConnection.connect("login.php", pairs);

    RootObject json = JsonConvert.DeserializeObject<RootObject>(await serverData);

    if (json.logined != "false")
    {
        _firsname = json.data.firsname;
        _lastname = json.data.lastname;
        _id = json.data.id;
        _phone = json.data.phone;
        _ProfilePic = json.data.profilePic;
        _thumbnail = json.data.thumbnail;
        _email = json.data.email;
        return true;
    }
    else
        return false;
}

回答1:

The return type of your function is Task<bool>, not bool itself. To get the result, you should use await keyword:

bool result = await authentication();

You can read "What Happens in an Async Method" section of this MSDN article to get more understanding on async / await language feature.

回答2:

You need to await the task:

bool result = await authentication();

Or, you can use your favourite alternate method of waiting on a Task.