Xamarin SDK
How to integrate with a Xamarin app
This guide provides instructions on integrating Authgear with a Xamarin app. Supported packages include:
Xamarin.Essentials 1.7.2 or higher
Xamarin.Forms 5.0.0.2401 or higher
Setup Application in Authgear
Signup for an Authgear Portal account in https://portal.authgear.com/. Or you can use your self-deployed Authgear.
From the Project listing, create a new Project or select an existing Project. After that, we will need to create an application in the project.
Step 1: Create an application in the Portal
Go to Applications on the left menu bar.
Click ⊕Add Application in the top tool bar.
Input the name of your application and select Native App as the application type. Click "Save".
You will see a list of guides that can help you for setting up, then click "Next".
Step 2: Configure the application
In your IDE (e.g. Visual Studio), define a custom URI scheme that the users will be redirected back to your app after they have authenticated with Authgear, e.g.
com.myapp.example://host/path
.[^1]Head back to Authgear Portal, fill in the Redirect URI that you have defined in the previous steps.
Click "Save" in the top tool bar and keep the Client ID. You can also obtain it again from the Applications list later.
If you wish to validate JSON Web Token (JWT) in your own application server, turn on "Issue JWT as access token".[^2] If you wish to forward authentication requests to Authgear Resolver Endpoint, leave this unchecked. See comparisons in Backend Integration.
Create a Xamarin app
Open Visual Studio
Create a new project
Choose the Xamarin.Forms template
Install the SDK
Search for "Authgear.Xamarin" on nuget.org and add it to your base project. https://www.nuget.org/packages/Authgear.Xamarin/
Authgear.Xamarin targets MonoAndroid 12.0 on Android, and Xamarin.iOS10 on iOS. Update the target framework of the Android and iOS projects to match Authgear.Xamarin's target frameworks.
Update Android and iOS project's Xamarin.Essentials to 1.7.2.
Platform Integration
To finish the integration, setup the app to handle the redirectURI specified in the application. This part requires platform specific integration.
Android
Define your own callback activity
Targeting API level 30 or above (Android 11 or above)
If your Android app is targeting API level 30 or above (Android 11 or above), you need to add a queries
section to AndroidManifest.xml
.
Initialize a global AuthgearSdk instance
In your MainActivity.cs
iOS
Add the following key-value pair in your iOS project Info.plist
Initialize a global AuthgearSdk instance
In your AppDelegate.cs
Try authenticate
Edit your MainPage.xaml
Edit your MainPage.xaml.cs
Get the Logged In State
When you start launching the application. You may want to know if the user has logged in. (e.g. Show users the login page if they haven't logged in). The SessionState
reflects the user logged in state in the SDK locally on the device. That means even the SessionState
is Authenticated
, the session may be invalid if it is revoked remotely. After initializing the Authgear SDK, call FetchUserInfoAsync
to update the SessionState
as soon as it is proper to do so.
The value of SessionState
can be Unknown
, NoSession
or Authenticated
. Initially, the SessionState
is Unknown
. After a call to authgear.configure
, the session state would become Authenticated
if a previous session was found, or NoSession
if such session was not found.
Fetching User Info
In some cases, you may need to obtain current user info through the SDK. (e.g. Display email address in the UI). Use the FetchUserInfoAsync
function to obtain the user info, see example.
Logout
To log out the user from the current app session, you need to invoke thelogout
function.
Calling An API
To include the access token to the HTTP requests to your application server, you set the bearer token manually by using authgear.AccessToken
.
Using HttpClient
You can get the access token through authgear.AccessToken
. Call RefreshAccessTokenIfNeededAsync
every time before using the access token, the function will check and make the network call only if the access token has expired. Then, include the access token into the Authorization header of the http request.
Next steps
To protect your application server from unauthorized access. You will need to integrate your backend with Authgear.
Backend IntegrationXamarin SDK Reference
For detailed documentation on the Xamarin SDK, visit Xamarin SDK Reference
Footnote
[^1]: For further instruction on setting up custom URI scheme in Xamarin, see https://www.xamarinhelp.com/uri-scheme/ [^2]: For more explanation on JWT, see https://en.wikipedia.org/wiki/JSON_Web_Token
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