Google登录集成（Android）

测试google登录的条件：
1、手机具备翻墙能力
2、手机为google手机或者安装有google服务
3、应用必须被正确的签名文件签名
参考google开发文档：
https://developers.google.com/identity/sign-in/android/sign-in
集成步骤：
第一步：注册登录google移动平台
第二步：添加你的超赞项目，设置地区

第三步：创建项目完成后，选择集成平台

第四步：选择Android，设置包名、sha1等信息

第五步：注册应用，然后跳转的页面中切记要下载json文件，并将json文件放到主module根目录下

第六步：
项目级 build.gradle（/build.gradle）：
buildscript {
dependencies {
// Add this line
classpath ‘com.google.gms:google-services:3.2.0’
}
}

应用级 build.gradle：
dependencies {
// Add this line
compile ‘com.google.firebase:firebase-core:12.0.1’
}
…
// Add to the bottom of the file
apply plugin: ‘com.google.gms.google-services’
第七步：环境配置完成，Sync Now…
第八步：sdk 需要下载google_play_services

第九步：定义初始化回调接口，定义登录回调接口：

public interface GoogleInitListener {
    void initFinish(GoogleSignInAccount account,GoogleSignInClient client );
}
public interface GoogleLoginListener {
    void loginSuccess(GoogleSignInAccount account);
    void LoginFailed(String msg);
}

第十步：点击google登录按钮开始进行初始化：

String google_app_id = "your app id";
public void gooleAuthInit( Activity activity,GoogleInitListener googleInitListener){
    GoogleSignInOptions gso = new GoogleSignInOptions
                    .Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                    .requestIdToken(googleId)
                    .requestEmail()
                    .build();

    GoogleSignInClient mGoogleSignInClient = GoogleSignIn.getClient(activity, gso);
    //如果用戶已经登录返回account对象，没有登录 返回null
    GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(activity);
    if(account==null){
        //初始化完成，检查到google账户没有登录
        googleInitListener.initFinish(null,mGoogleSignInClient);
    }else{
        //初始化完成，检查到google账户已经登录，返回账号信息
        googleInitListener.initFinish(account,mGoogleSignInClient);
    }
}

第十一步：收到初始化回调对象时，调用登录：

private GoogleLoginListener mGoogleAuthListener;
//打开google登录页
public void gooleAuthLogin(Activity activity,  GoogleSignInClient mGoogleSignInClient,GoogleLoginListener googleAuthListener){
        mGoogleAuthListener = googleAuthListener;
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        activity.startActivityForResult(signInIntent,RC_SIGN_IN);
}
//登录结果返回
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    // Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);
    if (requestCode == RC_SIGN_IN) {
        // The Task returned from this call is always completed, no need to attach
        Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
        handleSignInResult(task);
    }
}
//处理登录结果，并回调登录结果
private void handleSignInResult(Task<GoogleSignInAccount> completedTask) {
    try {
        GoogleSignInAccount account = completedTask.getResult(ApiException.class);
        // Signed in successfully, show authenticated UI.
        mGoogleAuthListener.loginSuccess(account);
    } catch (ApiException e) {
        // The ApiException status code indicates the detailed failure reason.
        // Please refer to the GoogleSignInStatusCodes class reference for more information.
        Log.w(TAG, "signInResult:failed code=" + e.getStatusCode());
        Log.d(TAG, e.getMessage());
        e.printStackTrace();
        mGoogleAuthListener.LoginFailed(e.getStatusCode()+","+e.getMessage());
    }
}

登录流程到此结束，欢迎大家留言批评指正，谢谢！