android - 检查用户是否已经使用 Auth.GoogleSignInApi 登录？

Question

我发现为了让用户登录，我必须使用以下代码:

Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
startActivityForResult(signInIntent, RC_SIGN_IN);

退出

new ResultCallback<Status>() {
                @Override
                public void onResult(Status status) {
                    disconnect();
                }
            });

但是当用户重新启动应用程序并且他已经登录(之前没有注销)时，是否有可能检测到这种“当前登录”状态？

显然，可以在应用程序的设置(共享首选项)中保存“已登录”，但是有什么方法可以使用 google api 进行检测？

Answer 1

Here我找到了解决方案:

  OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);
        if (opr.isDone()) {
            // If the user's cached credentials are valid, the OptionalPendingResult will be "done"
            // and the GoogleSignInResult will be available instantly.
            Log.d(TAG, "Got cached sign-in");
            GoogleSignInResult result = opr.get();
            handleSignInResult(result);
        } else {
            // If the user has not previously signed in on this device or the sign-in has expired,
            // this asynchronous branch will attempt to sign in the user silently.  Cross-device
            // single sign-on will occur in this branch.
            showProgressDialog();
            opr.setResultCallback(new ResultCallback<GoogleSignInResult>() {
                @Override
                public void onResult(GoogleSignInResult googleSignInResult) {
                    hideProgressDialog();
                    handleSignInResult(googleSignInResult);
                }
            });
        }