Question

我正在尝试允许新用户上传个人资料图片，但是每当我尝试注册时，应用程序就会崩溃。调试该应用程序后，我发现它总是由于第175行的用户ID为空而发生。第175行是：DatabaseReference myRef = firebaseDatabase.getReference（firebaseAuth.getUid（））;

我一直在关注YouTube教程，https://www.youtube.com/watch?v=-v1O9rxienU，即使我们使用相同的代码，他上传的图像也没有问题。我该如何解决？

这是调试控制台中的错误文本：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.fbla_mobileapp, PID: 31103
    java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.firebase.storage.StorageReference com.google.firebase.storage.StorageReference.child(java.lang.String)' on a null object reference
        at com.example.fbla_mobileapp.Register_Form.sendUserData(Register_Form.java:176)
        at com.example.fbla_mobileapp.Register_Form.access$400(Register_Form.java:41)
        at com.example.fbla_mobileapp.Register_Form$2$1.onComplete(Register_Form.java:116)
        at com.google.android.gms.tasks.zzj.run(Unknown Source:4)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:205)
        at android.app.ActivityThread.main(ActivityThread.java:6991)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:884)

和代码：

    private EditText userName, userPassword, userEmail, userGrade;
private Button regButton;
private TextView userLogin;
private FirebaseAuth firebaseAuth;
private ImageView userProfilePic;
String email, name, grade, password;
private FirebaseStorage firebaseStorage;
private static int PICK_IMAGE = 123;
Uri imagePath;
private StorageReference storageReference;


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(requestCode == PICK_IMAGE && resultCode == RESULT_OK && data.getData() != null){
        imagePath = data.getData();
        try {
            Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), imagePath);
            userProfilePic.setImageBitmap(bitmap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}



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


    firebaseAuth = FirebaseAuth.getInstance();
    firebaseStorage = FirebaseStorage.getInstance();

    final StorageReference storageReference = firebaseStorage.getReference();


    userProfilePic.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //  Intent galleryIntent = new Intent();
            //  galleryIntent.setAction(Intent.ACTION_GET_CONTENT);
            // galleryIntent.setType("image/*");
            // startActivityForResult(galleryIntent, Gallery_Pick);
            Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent, "Select Image"), PICK_IMAGE);


        }
    });



    regButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(validate()){
                //upload to database
                //StorageReference myRef1 = storageReference.child(firebaseAuth.getUid());
                String user_email = userEmail.getText().toString().trim();
                String user_password = userPassword.getText().toString().trim();

                firebaseAuth.createUserWithEmailAndPassword(user_email, user_password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {

                            if (task.isSuccessful()) {
                                sendUserData(task.getResult().getUser());
                            firebaseAuth.signOut();
                            Toast.makeText(Register_Form.this, "Registration Successful", Toast.LENGTH_SHORT).show();
                            startActivity(new Intent(Register_Form.this, login_screen.class));
                        }else{
                            Toast.makeText(Register_Form.this, "Registration Failed", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }

        }
    });

    userLogin.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(Register_Form.this, login_screen.class ));
        }
    });



    }


private void setupUiViews(){
    userName = (EditText)findViewById(R.id.etName);
    userEmail = (EditText)findViewById(R.id.etEmail);
    userPassword = (EditText)findViewById(R.id.etPass);
    regButton = (Button)findViewById(R.id.btnRegister);
   // regButton.setOnClickListener();
    userLogin = (TextView)findViewById(R.id.tvSIgn_In);
    userGrade = (EditText)findViewById(R.id.etGrade);
    userProfilePic =(ImageView)findViewById(R.id.ivProfile);

}


private Boolean validate(){

    Boolean result = false;

     name = userName.getText().toString();
     password = userPassword.getText().toString();
     email = userEmail.getText().toString();
     grade = userGrade.getText().toString();

    if(name.isEmpty() || password.isEmpty() || email.isEmpty() || grade.isEmpty() || imagePath == null ) {
        Toast.makeText(this, "Please enter all details", Toast.LENGTH_SHORT).show();
    }else{
        result = true;
    }
    return result;
}

private void sendUserData(FirebaseUser user){

    FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
    DatabaseReference myRef = firebaseDatabase.getReference(firebaseAuth.getUid());
   StorageReference imageReference = storageReference.child(firebaseAuth.getUid()).child("Images").child("Profile Pic");  //User id/Images/Profile Pic.jpg
   UploadTask uploadTask = imageReference.putFile(imagePath);
   uploadTask.addOnFailureListener(new OnFailureListener() {
       @Override
       public void onFailure(@NonNull Exception e) {
           Toast.makeText(Register_Form.this, "Upload failed!", Toast.LENGTH_SHORT).show();
       }
   }).addOnCompleteListener(new OnCompleteListener<UploadTask.TaskSnapshot>() {
        @Override
        public void onComplete(@NonNull Task<UploadTask.TaskSnapshot> task) {
            Toast.makeText(Register_Form.this, "Upload successful!", Toast.LENGTH_SHORT).show();
     }
    });
    UserProfile userProfile = new UserProfile(grade, email, name);
    myRef.setValue(userProfile);
}

}

Answer 1

创建/登录用户后，Set-AuthenticodeSignature可能不会立即更新。为了防止出现竞争状况，您需要将user from the AuthResult传递到FirebaseAuth.getInstance().getCurrentUser()中。

sendUserData

然后在您的firebaseAuth.createUserWithEmailAndPassword(user_email, user_password).addOnCompleteListener(new OnCompleteListener<AuthResult>() { @Override public void onComplete(@NonNull Task<AuthResult> task) { if (task.isSuccessful()) { sendUserData(task.getResult().getUser()); ...中，您从该用户那里获得UID，而不是全局对象：

sendUserData

无法将图片上传到Fire Base

1 个答案: