Integrating Google Sign-In in Android Apps

With the increasing popularity of Google as an identity provider, it has become essential for Android app developers to integrate Google Sign-In functionality into their applications. In this blog post, we will explore how to integrate Google Sign-In in Android apps using Kotlin and Java.

Prerequisites

Before we begin, make sure you have the following prerequisites:

1. An Android development environment setup with either Kotlin or Java.
2. A Google API Console project created with the necessary credentials for Google Sign-In.

Steps to integrate Google Sign-In in Android Apps

Step 1: Add the necessary dependencies

Open your app-level build.gradle file and add the following dependencies:

implementation 'com.google.android.gms:play-services-auth:19.2.0'

Sync your project to make sure the dependencies are properly added.

Step 2: Configure the Google API Console project

To enable sign-in with Google, you need to create a project in the Google API Console and generate the necessary credentials. Follow this guide to create a project and configure the necessary credentials.

Remember to add your application's SHA-1 fingerprint to the project for authentication.

Step 3: Add the Google Sign-In Button to your layout

In your XML layout file, add the following code to include the Google Sign-In Button:

<com.google.android.gms.common.SignInButton
    android:id="@+id/signInButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="16dp"
    android:layout_marginBottom="16dp" />

Step 4: Initialize the Google Sign-In Client

In your activity or fragment, initialize the Google Sign-In client in the onCreate() method:

private lateinit var googleSignInClient: GoogleSignInClient

// ...

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
        .requestEmail()
        .build()

    googleSignInClient = GoogleSignIn.getClient(this, gso)
}

Step 5: Add Sign-In functionality

Add the following code to handle the Google Sign-In button click:

signInButton.setOnClickListener {
    val signInIntent = googleSignInClient.signInIntent
    startActivityForResult(signInIntent, RC_SIGN_IN)
}

Handle the sign-in result in onActivityResult():

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == RC_SIGN_IN) {
        val task = GoogleSignIn.getSignedInAccountFromIntent(data)
        handleSignInResult(task)
    }
}

Step 6: Handle Sign-In Result

Implement the handleSignInResult() function to process the sign-in result:

private fun handleSignInResult(completedTask: Task<GoogleSignInAccount>) {
    try {
        val account = completedTask.getResult(ApiException::class.java)
        // Signed in successfully, handle the user's account details
        val displayName = account?.displayName
        val email = account?.email
        val photoUrl = account?.photoUrl
        
        // TODO: Do something with the account details
        
    } catch (e: ApiException) {
        // Sign in failed, handle the error
        Log.e(TAG, "Sign-in failed. Error code: ${e.statusCode}")
    }
}

That's it! You have successfully integrated Google Sign-In in your Android app.

Conclusion

Integrating Google Sign-In in Android apps provides users with a convenient and secure way to sign in. In this blog post, we explored the steps to integrate Google Sign-In functionality in Android apps using Kotlin and Java. Feel free to customize the implementation based on your app's requirements and enhance the user experience with additional features. Happy coding!

本文来自极简博客，作者：晨曦微光，转载请注明原文链接：Integrating Google Sign-In in Android Apps