Question

我是编程的新手，正在尝试通过以下教程学习。我正在关注一个教程，遇到了一个问题，不知道要解决它。在我的MainActivity中，我尝试通过电子邮件和密码对用户进行身份验证。（工作良好）。之后，HomenActivity应该开始。虽然如此，但由于某种原因它无法启动。不幸的是，我无法理解为什么。如果您能为我指明正确的方向，那将是无比感激。

谢谢大家。

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Toast;

import com.firebase.ui.auth.AuthUI;

import com.firebase.ui.auth.IdpResponse;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.InstanceIdResult;
import com.karumi.dexter.Dexter;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.PermissionDeniedResponse;
import com.karumi.dexter.listener.PermissionGrantedResponse;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.single.PermissionListener;
import com.raindevteam.aservicetracking.Model.User;
import com.raindevteam.aservicetracking.Utils.Common;

import java.util.Arrays;
import java.util.List;

import io.paperdb.Paper;

import static java.sql.DriverManager.println;

public class MainActivity extends AppCompatActivity {

    DatabaseReference user_information;
    private static final int MY_REQUEST_CODE = 7117;
    List<AuthUI.IdpConfig> providers;

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

        Paper.init(this);

        user_information = FirebaseDatabase.getInstance().getReference(Common.USER_INFORMATION);

        providers = Arrays.asList(
                new AuthUI.IdpConfig.EmailBuilder().build(),
                new AuthUI.IdpConfig.GoogleBuilder().build()
                );

        Dexter.withActivity(this)
                .withPermission(Manifest.permission.ACCESS_FINE_LOCATION)
                .withListener(new PermissionListener() {
            @Override
            public void onPermissionGranted(PermissionGrantedResponse response) {
                showSignInOption();
            }

            @Override
            public void onPermissionDenied(PermissionDeniedResponse response) {
                Toast.makeText(MainActivity.this, "You need to Accept permission",Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onPermissionRationaleShouldBeShown(PermissionRequest permission, PermissionToken token) {

            }
        }).check();
    }

    private void showSignInOption(){
        startActivityForResult(
                AuthUI.getInstance()
                        .createSignInIntentBuilder()
                        .setAvailableProviders(providers)
                        .build(),MY_REQUEST_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == MY_REQUEST_CODE){
            IdpResponse response = IdpResponse.fromResultIntent(data);
            if(requestCode == RESULT_OK){

                final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

                user_information.orderByKey()
                        .equalTo(firebaseUser.getUid())
                        .addListenerForSingleValueEvent(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                                if(dataSnapshot.getValue() == null){
                                    if(!dataSnapshot.child(firebaseUser.getUid()).exists()){
                                        Common.loggedUser = new User(firebaseUser.getUid(),firebaseUser.getEmail());
                                        //add to database
                                        user_information.child(Common.loggedUser.getUid())
                                                .setValue(Common.loggedUser);
                                    }
                                }
                                //if user exists
                                else{
                                    Common.loggedUser = dataSnapshot.child(firebaseUser.getUid()).getValue(User.class);

                                }

                                Paper.book().write(Common.USER_UID_SAVE_KEY, Common.loggedUser.getUid());
                                updateToken(firebaseUser);

                                setupUI();


                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError databaseError) {

                            }
                        });
            }
        }
    }

    private void setupUI(){

        startActivity(new Intent(MainActivity.this, HomeActivity.class));
        finish();
    }

    private void updateToken(final FirebaseUser firebaseUser){
        final DatabaseReference tokens = FirebaseDatabase.getInstance().getReference(Common.TOKENS);

        FirebaseInstanceId.getInstance().getInstanceId().addOnSuccessListener(new OnSuccessListener<InstanceIdResult>() {
            @Override
            public void onSuccess(InstanceIdResult instanceIdResult) {
                tokens.child(firebaseUser.getUid()).setValue(instanceIdResult.getToken());

            }
        }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                Toast.makeText(MainActivity.this,"Error"+e.getMessage(),Toast.LENGTH_SHORT).show();
            }
        });
    }
}

没有显示错误消息。

Answer 1

我认为您的setupUI（）没有运行，请尝试打印Log.e。检查它是否正常工作。

Answer 2

您会尝试吗？

private void setupUI(){

    startActivity(new Intent(this, HomeActivity.class));
    finish();
}

新活动无法启动

2 个答案: