Question

根据this帖子和其他一些博客文章，在MVP安卓应用中的演示者中使用活动上下文是不好的。如果演示者中的某个方法需要“活动”上下文，如何删除演示者中的“活动”上下文并仍然让演示者完成完成所需的工作，该怎么办？

在此Activity中，它在演示者中调用firebaseAuthWithGoogle方法。通过将活动，视图和 FirebaseAuth 传递给构造函数来初始化演示者。

public class GoogleSignInActivity extends AppCompatActivity implements
        GoogleApiClient.OnConnectionFailedListener, View.OnClickListener, GoogleSignInView {
    private static final String TAG = "SignInActivity";
    private static final int RC_SIGN_IN = 9001;

    private SignInButton mSignInButton;

    private GoogleApiClient mGoogleApiClient;

    // Firebase instance variables
    private FirebaseAuth mFirebaseAuth;

    private GoogleSignInPresenter googleSignInPresenter;

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

        mSignInButton = (SignInButton) findViewById(R.id.btn_sign_in);
        mSignInButton.setOnClickListener(this);

        // Configure Google Sign In
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this /* FragmentActivity */, this /* OnConnectionFailedListener */)
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();

        // Initialize FirebaseAuth
        mFirebaseAuth = FirebaseAuth.getInstance();

        googleSignInPresenter = new GoogleSignInPresenter(this, this, mFirebaseAuth);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_sign_in:
                googleSignInPresenter.onSignInClick();
                break;
            default:
                return;
        }
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RC_SIGN_IN) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            if (result.isSuccess()) {
                GoogleSignInAccount account = result.getSignInAccount();
                googleSignInPresenter.firebaseAuthWithGoogle(account);
            } else {
                Log.e(TAG, "Google Sign-In failed.");
            }
        }
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Log.d(TAG, "onConnectionFailed:" + connectionResult);
        Toast.makeText(this, "Google Play Services error.", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void startSignInIntent() {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    @Override
    public void startMainActivity() {
        startActivity(new Intent(GoogleSignInActivity.this, MainActivity.class));
        finish();
    }


}

此演示者中的firebaseAuthWithGoogle方法需要addOnCompleteListener中的Activity上下文。

public class GoogleSignInPresenter {
    public static final String TAG = "GoogleSignInPresenter";

    private GoogleSignInView googleSignInView;
    private FirebaseAuth firebaseAuth;
    private GoogleSignInActivity googleSignInActivity;

    public GoogleSignInPresenter(GoogleSignInActivity googleSignInActivity, GoogleSignInView googleSignInView, FirebaseAuth firebaseAuth) {
        this.googleSignInActivity = googleSignInActivity;
        this.googleSignInView = googleSignInView;
        this.firebaseAuth = firebaseAuth;
    }

    public void onSignInClick() {
        googleSignInView.startSignInIntent();
    }


    public void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d(TAG, "firebaseAuthWithGooogle:" + acct.getId());
        AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
        firebaseAuth.signInWithCredential(credential)
                .addOnCompleteListener(googleSignInActivity, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        Log.d(TAG, "signInWithCredential:onComplete:" + task.isSuccessful());
                        if (!task.isSuccessful()) {
                            Log.w(TAG, "signInWithCredential", task.getException());
                        } else {
                            googleSignInView.startMainActivity();
                        }
                    }
                });
    }
}

Answer 1

我很确定你可以删除活动实例，例如

.addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    Log.d(TAG, "signInWithCredential:onComplete:" + task.isSuccessful());
                    if (!task.isSuccessful()) {
                        Log.w(TAG, "signInWithCredential", task.getException());
                    } else {
                        googleSignInView.startMainActivity();
                    }
                }
            });

阅读本文：https://developers.google.com/android/guides/tasks

如何在需要时删除Presenter中的Activity上下文？

1 个答案: