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我梦想着打造一个不需要新建类的recycleviewqwq
compile ‘com.android.support:recyclerview-v7:24.2.1’ <android.support.v7.widget.RecyclerView android:id="@+id/recycler_view" …① ViewHolder 的构造函数中要传入一个View 参数,这个参数通常就是RecyclerView子项的最外层布局 通过从最外层布局入手找到里面那俩~ qwq 所以①处的代码先是继承,然后找到了其他两
② 这个类本身的构造函数 用于把要展示的数据源传进来,并赋值给一个全局变量mFruitList ,我们后续的操作都将在这个数据源的基础上进行。类型为List 还封装的挺好qwq ③ 由于是继承的之前的adapter, 所以剩下三个都是在重写了饿 onCreateViewHolder() 方法是用于创建ViewHolder 实例的,我们在这个方法中将fruit_item 布局加载进来,然后创建一个ViewHolder 实例,并把加载出来的布局传入到构造函数当中,最后将ViewHolder 的实例返回 onBindViewHolder() 方法是用于对RecyclerView子项的数据进行赋值的,会在每个子项被滚动到屏幕内的时候执行,这里我们通过position 参数得到当前项的Fruit 实例,然后再将数据设置到ViewHolder 的ImageView和TextView当中即可。 getItemCount()是有多少子项private ListfruitList = new ArrayList<>();....initFruits(); // 初始化水果数据 RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view); LinearLayoutManager layoutManager = new LinearLayoutManager(this); recyclerView.setLayoutManager(layoutManager); FruitAdapter adapter = new FruitAdapter(fruitList); recyclerView.setAdapter(adapter);
或者 StaggeredGridLayoutManager layoutManager = new
StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL); recyclerView.setLayoutManager(layoutManager);onCreateViewHolder里面
之前是把holder实例化并加载了布局,现在可以进一步搞这个holder。给它注册点击事件,然后判断你点了啥。这里,是分开设置点击事件的,也就是说我真傻,我单知道…… 那是因为没有图片地址啊啊
最后的 适配器代码package com.example.mol74.recycleviewdemo;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast;import java.util.List;public class FruitAdapter extends RecyclerView.Adapter{ private List mFruitList; static class ViewHolder extends RecyclerView.ViewHolder { View fruitView; ImageView fruitImage; TextView fruitName; public ViewHolder(View view) { super(view); fruitView = view; fruitImage = (ImageView) view.findViewById(R.id.fruit_image); fruitName = (TextView) view.findViewById(R.id.fruit_name); } } public FruitAdapter(List fruitList) { mFruitList = fruitList; } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false); final ViewHolder holder = new ViewHolder(view); holder.fruitView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "you clicked view " + fruit.getName(), Toast.LENGTH_SHORT).show(); } }); holder.fruitImage.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "you clicked image " + fruit.getName(), Toast.LENGTH_SHORT).show(); } }); return holder; } @Override public void onBindViewHolder(ViewHolder holder, int position) { Fruit fruit = mFruitList.get(position); holder.fruitImage.setImageResource(fruit.getImageId()); holder.fruitName.setText(fruit.getName()); } @Override public int getItemCount() { return mFruitList.size(); }}
Main函数 … 这个下面好多是没用的
package com.example.mol74.recycleviewdemo;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.StaggeredGridLayoutManager;import java.util.ArrayList;import java.util.List;import java.util.Random;public class MainActivity extends AppCompatActivity { private ListfruitList = new ArrayList (); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initFruits(); RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view); StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL); recyclerView.setLayoutManager(layoutManager); FruitAdapter adapter = new FruitAdapter(fruitList); recyclerView.setAdapter(adapter); } private void initFruits() { for (int i = 0; i < 2; i++) { Fruit apple = new Fruit(getRandomLengthName("Apple"), R.drawable.ic_launcher_background); fruitList.add(apple); Fruit banana = new Fruit(getRandomLengthName("Banana"), R.drawable.ic_launcher_foreground); fruitList.add(banana); Fruit orange = new Fruit(getRandomLengthName("Orange"), R.drawable.ic_launcher_foreground); fruitList.add(orange); Fruit watermelon = new Fruit(getRandomLengthName("Watermelon"), R.drawable.ic_launcher_foreground); fruitList.add(watermelon); Fruit pear = new Fruit(getRandomLengthName("Pear"), R.drawable.ic_launcher_foreground); fruitList.add(pear); Fruit grape = new Fruit(getRandomLengthName("Grape"), R.drawable.ic_launcher_foreground); fruitList.add(grape); Fruit pineapple = new Fruit(getRandomLengthName("Pineapple"), R.drawable.ic_launcher_foreground); fruitList.add(pineapple); Fruit strawberry = new Fruit(getRandomLengthName("Strawberry"), R.drawable.ic_launcher_foreground); fruitList.add(strawberry); Fruit cherry = new Fruit(getRandomLengthName("Cherry"), R.drawable.ic_launcher_foreground); fruitList.add(cherry); Fruit mango = new Fruit(getRandomLengthName("Mango"), R.drawable.ic_launcher_foreground); fruitList.add(mango); } } private String getRandomLengthName(String name) { Random random = new Random(); int length = random.nextInt(20) + 1; StringBuilder builder = new StringBuilder(); for (int i = 0; i < length; i++) { builder.append(name); } return builder.toString(); }}
在这里。子项的监听不能用于启动活动,需要写个接口,因为adapter不是活动嘛,,,他只是个类,用接口在main里用
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