ListView和RecycleView显示问题

2019-01-16 02:49:12 123 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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ListView、GridView、RecycleView性能优化小总结 RecycleView控件的出现是为了替代ListView和GridView控件的，号称，是他们的加强版，在性能上做了优化处理，这里总结一下优化的地方。 1，在以往使用ListView或者GridView的时候，如果要进行性能优化，基本上两个做法： ①定义内部类ViewHolder；定义ViewHolder是为了减少findViewById的次数，如果每一次渲染布局都进行一轮的find... 阅读详情

代码检查了好几遍都不知道出错在哪
把RecyclerView的代码附上
希望有大神帮忙
FruitAdapter适配器代码：
public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> {
private List<Fruit> mFruitList;

public FruitAdapter(List<Fruit> fruitList){
mFruitList=fruitList;

}
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view=LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.fruit_item,viewGroup,false);
ViewHolder holder=new ViewHolder(view);
return holder;
}

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int i) {
Fruit fruit=mFruitList.get(i);
holder.fruitname.setText(fruit.getName());
holder.fruitimage.setImageResource(fruit.getImageId());
}

@Override
public int getItemCount() {
return mFruitList.size();
}

static class ViewHolder extends RecyclerView.ViewHolder{
ImageView fruitimage;
TextView fruitname;
public ViewHolder(@NonNull View itemView) {
super(itemView);
fruitimage=(ImageView)itemView.findViewById(R.id.fruit_image);
fruitname=(TextView)itemView.findViewById(R.id.fruit_name);
}
}
}

MainActivity代码
public class MainActivity extends AppCompatActivity {

private List<Fruit> fruitList=new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
RecyclerView recyclerView=(RecyclerView)findViewById(R.id.recycler);
LinearLayoutManager layoutManager=new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
FruitAdapter adapter=new FruitAdapter(fruitList);
recyclerView.setAdapter(adapter);

}

private void init(){
for(int i=0;i<2;i++){
Fruit a=new Fruit("a",R.mipmap.ic_launcher);
fruitList.add(a);
Fruit b=new Fruit("b",R.mipmap.ic_launcher);
fruitList.add(b);
Fruit c=new Fruit("c",R.mipmap.ic_launcher);
fruitList.add(c);
Fruit d=new Fruit("d",R.mipmap.ic_launcher);
fruitList.add(d);
Fruit e=new Fruit("e",R.mipmap.ic_launcher);
fruitList.add(e);
Fruit f=new Fruit("f",R.mipmap.ic_launcher);
fruitList.add(f);
Fruit g=new Fruit("g",R.mipmap.ic_launcher);
fruitList.add(g);
}
}
}

Fruit——item.xml代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">

<ImageView
android:id="@+id/fruit_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

<TextView
android:id="@+id/fruit_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="10dp"/>

</LinearLayout>

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