Question

嗨，朋友们，我正在从Firebase获取值并将其保存到edittext（已完成）。但是我要检查是否存在firebase值，而不是将其放在edittext上，否则要从用户在同一edittext上输入，因为我将此值发送到另一个活动，并且如果firebase中没有值，则会出现null值的错误

我正在尝试的代码是

      String  str= etext.getText().toString();

    if(str.equals("")) {

        final FirebaseDatabase database = FirebaseDatabase.getInstance();
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        String userId = user.getUid();
        DatabaseReference dbref = FirebaseDatabase.getInstance().getReference("Users/Clients").child(userId);
        dbref.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                Paper.book().write(Common.channel, etext.getText().toString());
                names = dataSnapshot.child("channel_id").getValue().toString();
                // Toast.makeText(getBaseContext(),names,Toast.LENGTH_LONG).show();
                etext.setText(names);
                SharedPreferences settings = getSharedPreferences("userInput", 0);
                SharedPreferences.Editor editor = settings.edit();
                editor.putString("username", names);
                editor.commit();


                Intent i = new Intent(Men.this, Main2Activity.class);
                startActivity(i);
                finish();
            }

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

            }
        });
    }

Answer 1

尝试以下

          public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                if (dataSnapshot.hasChild("channel_id") && dataSnapshot.child("channel_id").getValue() != null) {
                    names = dataSnapshot.child("channel_id").getValue().toString();
                    Paper.book().write(Common.channel, names);
                    etext.setText(names);
                    SharedPreferences settings = getSharedPreferences("userInput", 0);
                    SharedPreferences.Editor editor = settings.edit();
                    editor.putString("username", names);
                    editor.commit();
                    Intent i = new Intent(Men.this, Main2Activity.class);
                    startActivity(i);
                    finish();
                }
            }

在edittext上检查条件，以检查firebase值或接受用户输入

1 个答案: