保存項目由onDatachage

Question

從檢索到的數據的微調選擇的關鍵

我可以從我的數據庫中檢索數據firebase的spinner滿，但我不能保存項目選擇我放線

uaselected = uaSpinner.getSelectedItem().toString().trim();

昂達更改後保存選定的項目，但因爲它是第一次執行函數之前昂達改變任何幫助，請

Answer 1

使用這種方法，返回null。

spncountry.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
       @Override 
       public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
        country_data=spncountry.getSelectedItem().toString(); 
           } 

       @Override 
       public void onNothingSelected(AdapterView<?> parent) { 

       } 
      }); 

Answer 2

databasereference = database.getReference(); 
    mAuth = FirebaseAuth.getInstance(); 
    areaSpinner = (Spinner) findViewById(R.id.spinneretab); 

     databasereference.child("UA_unity").addValueEventListener(new com.google.firebase.database.ValueEventListener() { 
       @Override 
       public void onDataChange(com.google.firebase.database.DataSnapshot dataSnapshot) { 
        final List<String> etab = new ArrayList<String>(); 
        final List<String> keyunity = new ArrayList<String>(); 
        // uaselected = areaSpinner.getSelectedItem().toString().trim(); 


        for (DataSnapshot child: dataSnapshot.getChildren()) { 
         nameua = (String) child.child("nom_UA").getValue(); 
         keyua = child.getKey(); 
         // keyunity.add(keyua); 
         // databasereference.child("Users").child("UA_ID").setValue(keyua); 
         etab.add(nameua); 
        } 
        ArrayAdapter<String> areasAdapter = new ArrayAdapter<String>(add_info_user.this, android.R.layout.simple_spinner_item, etab); 
        areasAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
        areaSpinner.setAdapter(areasAdapter); 
        uaselected = areaSpinner.getSelectedItem().toString().trim(); 


       } 

       @Override 
       public void onCancelled(DatabaseError databaseError) { 

       }