CODEWITHSUNDEEP
c#asynchronousxamarinxamarin.androidasync-await
Agile Hobo
Agile Hobo

Reputation: 322

Using async/await still blocks UI on Xamarin.Android

I'm working on a Xamarin.Android project and the app needs to consume web service before updating the UI. I applied async/await but it still blocks the UI.

Here is the UI code

    private async void Login(object sender, EventArgs e)
    {
        var username = _usernamEditText.Text.Trim();
        var password = _passwordEditText.Text.Trim();
        var progressDialog = ProgressDialog.Show(this, "", "Logging in...");
        var result = await _userService.AuthenticateAsync(username, password);

        progressDialog.Dismiss();
    }

Here is the service code

public async Task<AuthenticationResult> AuthenticateAsync(string username, string password)
    {
        using (var httpClient = CreateHttpClient())
        {
            var url = string.Format("{0}/token", Configuration.ServiceBaseUrl);
            var body = new List<KeyValuePair<string, string>>
            {
                new KeyValuePair<string, string>("username", username),
                new KeyValuePair<string, string>("password", password),
                new KeyValuePair<string, string>("grant_type", "password")
            };
            var response = httpClient.PostAsync(url, new FormUrlEncodedContent(body)).Result;
            var content = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
            var obj = new JSONObject(content);
            var result = new AuthenticationResult {Success = response.IsSuccessStatusCode};

            if (response.IsSuccessStatusCode)
            {
                result.AccessToken = obj.GetString("access_token");
                result.UserName = obj.GetString("userName");
            }
            else
            {
                result.Error = obj.GetString("error");

                if (obj.Has("error_description"))
                {
                    result.ErrorDescription = obj.GetString("error_description");
                }
            }

            return result;
        }
    }

Do I miss anything? Thank you.

Upvotes: 3

Views: 3104

Answers (1)

Sami Kuhmonen
Sami Kuhmonen

Reputation: 31153

You're not awaiting PostAsync, you're just taking the Result. This makes the call synchronous.

Change that line to await and it will run asynchronously.

        var response = await httpClient.PostAsync(url, new FormUrlEncodedContent(body));

Upvotes: 9

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