如何使用Android Studio在模型中创建一个增量数字字符串值并在Firebase数据库中读取该值？

Question

例如。 我想要的Firebase数据的结构是这样的………………

 "Food" -> uid -> 1 - name& value 2 - name& value 3 - name& value -> uid -> 1 - name& value 2 - name& value 3 - name& value 

我只想从FirebaseDatabase检索数据，而无需通过应用程序输入任何数据。

如何在模型类中创建增量数字字符串值“ 1 ++”而不损害字符串

并使用回收站适配器将其读取为字符串值“ x”

还是有另一种方式来编码此coz，我还是这个新手

具有ViewHolder功能的FirebaseRecyclerAdapter

 @Override public void onStart() { super.onStart(); FirebaseRecyclerAdapter<Ingredients, IngredientsViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Ingredients, IngredientsViewHolder>( Ingredients.class, R.layout.list_single_ingredients, IngredientsViewHolder.class, mDatabase ) { @Override protected void populateViewHolder(IngredientsViewHolder viewHolder, Ingredients model, int position) { viewHolder.setX(model.getX()); } }; Ingredients_list.setAdapter(firebaseRecyclerAdapter); } //ViewHolder public static class IngredientsViewHolder extends RecyclerView.ViewHolder { View m2View; public IngredientsViewHolder(View itemView) { super(itemView); m2View = itemView; } public void setX(String x) { TextView IngredientsView = (TextView) m2View.findViewById(R.id.txt_ingredients); IngredientsView.setText(x); } } } 

我的模特班

 package Model; /** * Created by Keiren on 1/4/2018. */ public class Ingredients { public String x; public Ingredients() { } public Ingredients(String x) { this.x = x; } public String getX() {return x;} public void setX(String x) { this.x = x; } } 

Answer 1

要解决此问题，您首先需要将String转换为int，增加值，然后将int转换回String，如下所示：

String one = "1";
int two = Integer.valueOf(one);
two++;
String increasedValue = String.valueOf(two);
System.out.println(increasedValue);

输出将是：2

Answer 2

我找到了自己解决方案的答案，将其更改为

mDatabase = FirebaseDatabase.getInstance（）。getReference（）。child（“ Food”）。child（user_id）; 至

mDatabase = FirebaseDatabase.getInstance（）。getReference（“ Food”）。child（user_id）;

 "Food" -> uid -> 1 -> x - name& value 2 -> x- name& value 3 -> x- name& value -> uid -> 1 -> x - name& value 2 -> x - name& value 3 -> x - name& value