java - Google 登录后自动启动 Activity - Android Studio

Question

过去几天以来，我一直在尝试实现一些非常简单的目标，但我没有成功。

基本上，我使用 Google Developers 中的示例应用为我的应用创建登录流程。单击“登录”按钮后，我成功地从 Google 登录，并且还知道用户是否已经登录并验证了我的应用程序。

我想要做的是:当用户启动我的应用程序并且已经登录时，我想跳过登录屏幕并自动转到下一个 Activity 。

我做了很多测试，但我不会在这里发布我尝试过的所有内容，因为它有时非常困惑。这是我现在使用的代码:

我的MainActivity.java:

    public class MainActivity extends AppCompatActivity implements
        GoogleApiClient.OnConnectionFailedListener,
        View.OnClickListener {

    private static final String TAG = "SignInActivity";
    private static final int RC_SIGN_IN = 9001;

    private GoogleApiClient mGoogleApiClient;
    private ProgressDialog mProgressDialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Button listeners
        findViewById(R.id.sign_in_button).setOnClickListener(this);

        // [START configure_signin]
        // Configure sign-in to request the user's ID, email address, and basic
        // profile. ID and basic profile are included in DEFAULT_SIGN_IN.
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();
        // [END configure_signin]

        // [START build_client]
        // Build a GoogleApiClient with access to the Google Sign-In API and the
        // options specified by gso.
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this /* FragmentActivity */, this /* OnConnectionFailedListener */)
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();
        // [END build_client]

        // [START customize_button]
        // Customize sign-in button. The sign-in button can be displayed in
        // multiple sizes and color schemes. It can also be contextually
        // rendered based on the requested scopes. For example. a red button may
        // be displayed when Google+ scopes are requested, but a white button
        // may be displayed when only basic profile is requested. Try adding the
        // Scopes.PLUS_LOGIN scope to the GoogleSignInOptions to see the
        // difference.
        SignInButton signInButton = (SignInButton) findViewById(R.id.sign_in_button);
        signInButton.setSize(SignInButton.SIZE_STANDARD);
        signInButton.setScopes(gso.getScopeArray());
        // [END customize_button]
    }

    @Override
    public void onStart() {
        super.onStart();

        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);
                }
            });
        }
    }

    // [START onActivityResult]
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            handleSignInResult(result);
        }
    }
    // [END onActivityResult]

    // [START handleSignInResult]
    private void handleSignInResult(GoogleSignInResult result) {
        Log.d(TAG, "handleSignInResult:" + result.isSuccess());
        if (result.isSuccess()) {
            // Signed in successfully, show authenticated UI.
            GoogleSignInAccount acct = result.getSignInAccount();
            updateUI(true);

            Intent myIntent = new Intent(MainActivity.this, SplashScreen.class);
            startActivity(myIntent);
            finish();
        } else {
            // Signed out, show unauthenticated UI.
            updateUI(false);
        }
    }
    // [END handleSignInResult]

    // [START signIn]
    private void signIn() {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }
    // [END signIn]

    // [START signOut]
    private void signOut() {
        Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
                new ResultCallback<Status>() {
                    @Override
                    public void onResult(Status status) {
                        // [START_EXCLUDE]
                        updateUI(false);
                        // [END_EXCLUDE]
                    }
                });
    }
    // [END signOut]

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        // An unresolvable error has occurred and Google APIs (including Sign-In) will not
        // be available.
        Log.d(TAG, "onConnectionFailed:" + connectionResult);
    }

    private void showProgressDialog() {
        if (mProgressDialog == null) {
            mProgressDialog = new ProgressDialog(this);
            mProgressDialog.setMessage(getString(R.string.loading));
            mProgressDialog.setIndeterminate(true);
        }

        mProgressDialog.show();
    }

    private void hideProgressDialog() {
        if (mProgressDialog != null && mProgressDialog.isShowing()) {
            mProgressDialog.hide();
        }
    }

    private void updateUI(boolean signedIn) {
        if (signedIn) {
            findViewById(R.id.sign_in_button).setVisibility(View.GONE);
        } else {
            findViewById(R.id.sign_in_button).setVisibility(View.VISIBLE);
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.sign_in_button:
                signIn();
                break;
        }
    }
}

所以我的问题是:我应该如何以及在哪里表达进行下一个 Activity 的 Intent ？

Intent myIntent = new Intent(MainActivity.this, SplashScreen.class);
            startActivity(myIntent);

非常感谢您的帮助!如果您需要更多详细信息或解释，请告诉我。

Answer 1

将跳过登录屏幕后要显示的 Activity 类放入 YourClassAfterLogin.class

 private void handleSignInResult(GoogleSignInResult result) {
            Log.d(TAG, "handleSignInResult:" + result.isSuccess());
            if (result.isSuccess()) {
                // Signed in successfully, show authenticated UI.
                GoogleSignInAccount acct = result.getSignInAccount();
                updateUI(true);

                Intent myIntent = new Intent(MainActivity.this, YourClassAfterLogin.class);
                startActivity(myIntent);
                finish();
            } else {
                // Signed out, show unauthenticated UI.
                updateUI(false);
            }
        }