RecycleView代码不更新！更新代码应该怎么写呢，有没有人教一下
网络数据取到了，Recycleview 没显示出来数据
public class FoodFragment extends Fragment {
public RecyclerView mFoodRecyclerView;//定义RecyclerView
//定义以goodsentity实体类为对象的数据集合
private ArrayList<FoodEntity> goodsEntityList = new ArrayList<FoodEntity>();
//自定义recyclerveiw的适配器
private FoodRecycleAdapter mRecyclerAdapter;
private JSONArray array;
public FoodFragment() {
}
private static ChangeFoodFragment changeFoodFragment;
public static FoodFragment newInstance(ChangeFoodFragment foodFragment){
changeFoodFragment = foodFragment;
Bundle args = new Bundle();
FoodFragment fragment = new FoodFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.recyclerview_food, container, false);
//对recycleview进行配置
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
initData();
initRecyclerView(view);
}
private void initData() {
new Thread(){
public void run()
{
String url = DocUtil.food_list;
OkHttpClient okHttpClient = new OkHttpClient();
String token= CacheUtils.getString(getActivity(), "token", "");
RequestBody body = new FormBody.Builder()
.add("token",token)
.build();
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
Call call = okHttpClient.newCall(request);
try {
Response response = call.execute();
//System.out.println(response.body().string());
try {
final String string=response.body().string();
final JSONObject object=new JSONObject(string);
array=object.getJSONArray("list");
System.out.println(array);
if(array.length()>0) {
try {
FoodEntity foodEntity =new FoodEntity();
for(int i=0;i<array.length();i++){
JSONObject object1=array.getJSONObject(i);
foodEntity.setFoodtitle(object1.getString("foodtitle"));
foodEntity.setFoodcontent(object1.getString("foodcontent"));
foodEntity.setFoodcontentimg(object1.getString("foodcontentimg"));
System.out.println(object1.getString("foodtitle"));
System.out.println(object1.getString("foodcontent"));
System.out.println(object1.getString("foodcontentimg"));
}
} catch (Exception e) {
e.printStackTrace();
}
}else {
Toast.makeText(getActivity(), "无数据", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
// for (int i=0;i<10;i++){
// FoodEntity foodEntity =new FoodEntity();
// foodEntity.setName("模拟数据FOOD"+i);
// foodEntity.setContent("100"+i);
// goodsEntityList.add(foodEntity);
// }
}
private void initRecyclerView(View view) {
//获取RecyclerView
mFoodRecyclerView=view.findViewById(R.id.food_recyclerView);
//创建adapter
mRecyclerAdapter = new FoodRecycleAdapter(getActivity(), goodsEntityList);
//给RecyclerView设置adapter
mFoodRecyclerView.setAdapter( mRecyclerAdapter );
//设置layoutManager,可以设置显示效果，是线性布局、grid布局，还是瀑布流布局
//参数是：上下文、列表方向（横向还是纵向）、是否倒叙
mFoodRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));
//设置item的分割线
mFoodRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL));
//RecyclerView中没有item的监听事件，需要自己在适配器中写一个监听事件的接口。参数根据自定义
mRecyclerAdapter.setOnItemClickListener(new FoodRecycleAdapter.OnItemClickListener() {
@Override
public void OnItemClick(View view, FoodEntity data) {
Toast.makeText(getActivity(),"我是item",Toast.LENGTH_SHORT).show();
changeToAnotherFragment();
}
});
}
@SuppressLint("ResourceType")
private void changeToAnotherFragment() {
changeFoodFragment.changeFoodFragment();
}
}
public class FoodRecycleAdapter extends RecyclerView.Adapter<FoodRecycleAdapter.myViewHodler>{
private Context context;
private ArrayList<FoodEntity> goodsEntityList;
private ImageLoaderConfiguration configuration;
public DisplayImageOptions imageOptions;
private FoodRecycleAdapter adapter;
//创建构造函数
public FoodRecycleAdapter(Context context, ArrayList<FoodEntity> goodsEntityList) {
//将传递过来的数据，赋值给本地变量
this.context = context;//上下文
this.goodsEntityList = goodsEntityList;//实体类数据ArrayList
}
/**
* 创建viewhodler，相当于listview中getview中的创建view和viewhodler
*
* @param parent
* @param viewType
* @return
*/
@Override
public myViewHodler onCreateViewHolder(ViewGroup parent, int viewType) {
//创建自定义布局
View itemView = View.inflate(context, R.layout.food_item, null);
return new myViewHodler(itemView);
}
/**
* 绑定数据，数据与view绑定
*
* @param holder
* @param position
*/
@Override
public void onBindViewHolder(myViewHodler holder, int position) {
//根据点击位置绑定数据
FoodEntity data = goodsEntityList.get(position);
// holder.mItemGoodsImg;
configuration = ImageLoaderConfiguration.createDefault(context);
ImageLoader.getInstance().init(configuration);
imageOptions = DisplayImageOptions.createSimple();
holder.mItemGoodsName.setText(data.foodtitle);//获取实体类中的name字段并设置
holder.mItemContent.setText(data.foodcontent);//获取实体类中的price字段并设置
adapter=new FoodRecycleAdapter(context, goodsEntityList);
adapter.notifyItemRangeInserted(position,getItemCount());
// ImageLoader.getInstance().displayImage(DocUtil.base_url+
// data.foodcontentimg, mItemGoodsImg,
// imageOptions);
}
/**
* 得到总条数
*
* @return
*/
@Override
public int getItemCount() {
return goodsEntityList.size();
}
//自定义viewhodler
class myViewHodler extends RecyclerView.ViewHolder {
private ImageView mItemGoodsImg;
private TextView mItemGoodsName;
private TextView mItemContent;
public myViewHodler(View itemView) {
super(itemView);
mItemGoodsImg = itemView.findViewById(R.id.food_img);
mItemGoodsName = itemView.findViewById(R.id.food_title);
mItemContent = itemView.findViewById(R.id.tx_content);
//点击事件放在adapter中使用，也可以写个接口在activity中调用
//方法一：在adapter中设置点击事件
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//可以选择直接在本位置直接写业务处理
//Toast.makeText(context,"点击了xxx",Toast.LENGTH_SHORT).show();
//此处回传点击监听事件
if(onItemClickListener!=null){
onItemClickListener.OnItemClick(v, goodsEntityList.get(getLayoutPosition()));
}
}
});
}
}
/**
* 设置item的监听事件的接口
*/
public interface OnItemClickListener {
/**
* 接口中的点击每一项的实现方法，参数自己定义
*
* @param view 点击的item的视图
* @param data 点击的item的数据
*/
public void OnItemClick(View view, FoodEntity data);
}
//需要外部访问，所以需要设置set方法，方便调用
private FoodRecycleAdapter.OnItemClickListener onItemClickListener;
public void setOnItemClickListener(FoodRecycleAdapter.OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
}
使用listview就完美解决问题。
我不知道你说的是什么意思 但是我用sql更新
首先我我看不懂goodsEntity和foodEntity之间是什么关系
new Adapter的时候传进去的是goodsEntityList
但是网络请求得到的是foodEntity
其次网络请求后没有得写更新RV的代码
一般只要在网络请求后重新改一下数据源（或者可以说是数据集合）
然后adapter.notifyDataSetChanged();（这句可不写，但是是根据情况来的）
————————分割线————————
public class FoodFragment extends Fragment {
public RecyclerView mFoodRecyclerView;//定义RecyclerView
//定义以goodsentity实体类为对象的数据集合
private ArrayList<FoodEntity> goodsEntityList = new ArrayList<FoodEntity>();
//自定义recyclerveiw的适配器
private FoodRecycleAdapter mRecyclerAdapter;
private JSONArray array;
private Handler handler;
public FoodFragment() {
}
private static ChangeFoodFragment changeFoodFragment;
public static FoodFragment newInstance(ChangeFoodFragment foodFragment) {
changeFoodFragment = foodFragment;
Bundle args = new Bundle();
FoodFragment fragment = new FoodFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.recyclerview_food, container, false);
//对recycleview进行配置
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final ViewData viewData = new ViewData();
viewData.setView(view);
handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
System.out.println(msg);
switch (msg.what) {
case 1:
// 在这里去刷新UI
System.out.println(msg);
mRecyclerAdapter.notifyDataSetChanged();
break;
}
}
};
//初始化RV
initRecyclerView(view);
initData();
}
private void initData() {
new Thread() {
public void run() {
String url = DocUtil.food_list;
OkHttpClient okHttpClient = new OkHttpClient();
String token = CacheUtils.getString(getActivity(), "token", "");
RequestBody body = new FormBody.Builder()
.add("token", token)
.build();
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
Call call = okHttpClient.newCall(request);
try {
Response response = call.execute();
//System.out.println(response.body().string());
goodsEntityList.clear();
FoodEntity mfoodEntity;
for (int i = 0; i < 10; i++) {
mfoodEntity = new FoodEntity();
mfoodEntity.setFoodtitle("1");
mfoodEntity.setFoodcontent("2");
mfoodEntity.setFoodcontentimg("3");
goodsEntityList.add(mfoodEntity);
}
// try {
// final String string=response.body().string();
// final JSONObject object=new JSONObject(string);
//
// array=object.getJSONArray("list");
// System.out.println(array);
//
// if(array.length()>0) {
//
// try {
// FoodEntity foodEntity =new FoodEntity();
// for(int i=0;i<array.length();i++){
// JSONObject object1=array.getJSONObject(i);
// foodEntity.setFoodtitle(object1.getString("foodtitle"));
// foodEntity.setFoodcontent(object1.getString("foodcontent"));
// foodEntity.setFoodcontentimg(object1.getString("foodcontentimg"));
// System.out.println(foodEntity.getFoodtitle());
// System.out.println(foodEntity.getFoodcontent());
//
//
// }
//
//
//
//
//
//
//
//
//
// } catch (Exception e) {
// e.printStackTrace();
// }
// 获取到数据后，通知handle刷新UI
Message message = handler.obtainMessage();
message.what = 1;
handler.sendMessage(message);
// }else {
// Toast.makeText(getActivity(), "无数据", Toast.LENGTH_SHORT).show();
// }
// } catch (JSONException e) {
// e.printStackTrace();
// }
} catch (IOException e) {
e.printStackTrace();
}
}
}.start();
// for (int i=0;i<10;i++){
// FoodEntity foodEntity =new FoodEntity();
// foodEntity.setName("模拟数据FOOD"+i);
// foodEntity.setContent("100"+i);
// goodsEntityList.add(foodEntity);
// }
}
private void initRecyclerView(View view) {
//获取RecyclerView
mFoodRecyclerView = view.findViewById(R.id.food_recyclerView);
//创建adapter
mRecyclerAdapter = new FoodRecycleAdapter(getActivity(), goodsEntityList);
//给RecyclerView设置adapter
mFoodRecyclerView.setAdapter(mRecyclerAdapter);
//设置layoutManager,可以设置显示效果，是线性布局、grid布局，还是瀑布流布局
//参数是：上下文、列表方向（横向还是纵向）、是否倒叙
mFoodRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));
//设置item的分割线
mFoodRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL));
//RecyclerView中没有item的监听事件，需要自己在适配器中写一个监听事件的接口。参数根据自定义
mRecyclerAdapter.setOnItemClickListener(new FoodRecycleAdapter.OnItemClickListener() {
@Override
public void OnItemClick(View view, FoodEntity data) {
Toast.makeText(getActivity(), "我是item", Toast.LENGTH_SHORT).show();
changeToAnotherFragment();
}
});
}
@SuppressLint("ResourceType")
private void changeToAnotherFragment() {
changeFoodFragment.changeFoodFragment();
}
}
你的FoodFragment中我没看到有去初始化goodsEntityList的数据，如果是在这里初始化的那么你可以改下。还有其中的initData();是另起线程去获取的，所以可以这样认为initData()和initRecyclerView(view);几乎都同时执行了，在initData()数据还没获取到时和initRecyclerView(view);已经刷新了UI，解决办法是在数据获取成功后在执行initRecyclerView(view)。另外initRecyclerView(view);只能在UI线程里执行，所以你要换成UI线程，用new Thread()是不行的，改成下面的方式试下
package com.example.qw.dualnavigation.fragment;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.example.qw.dualnavigation.Interface.ChangeFoodFragment;
import com.example.qw.dualnavigation.R;
import com.example.qw.dualnavigation.adapter.FoodRecycleAdapter;
import com.example.qw.dualnavigation.bean.FoodEntity;
import com.example.qw.dualnavigation.bean.ViewData;
import org.json.JSONArray;
import java.util.ArrayList;
public class FoodFragment extends Fragment {
public RecyclerView mFoodRecyclerView;//定义RecyclerView
//定义以goodsentity实体类为对象的数据集合
private ArrayList goodsEntityList = new ArrayList();
//自定义recyclerveiw的适配器
private FoodRecycleAdapter mRecyclerAdapter;
private JSONArray array;
private Handler handler;
public FoodFragment() {
}
private static ChangeFoodFragment changeFoodFragment;
public static FoodFragment newInstance(ChangeFoodFragment foodFragment){
changeFoodFragment = foodFragment;
Bundle args = new Bundle();
FoodFragment fragment = new FoodFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.recyclerview_food, container, false);
//对recycleview进行配置
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
final ViewData viewData =new ViewData();
viewData.setView(view);
handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
System.out.println(msg);
switch (msg.what) {
case 1:
// 在这里去刷新UI
System.out.println(msg);
initRecyclerView(viewData.getView());
break;
}
}
};
initData();
}
private void initData() {
new Thread(){
public void run()
{
/*String url = DocUtil.food_list;
OkHttpClient okHttpClient = new OkHttpClient();
String token= CacheUtils.getString(getActivity(), "token", "");
RequestBody body = new FormBody.Builder()
.add("token",token)
.build();
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
Call call = okHttpClient.newCall(request);
try {
Response response = call.execute();
//System.out.println(response.body().string());
try {
final String string=response.body().string();
final JSONObject object=new JSONObject(string);
array=object.getJSONArray("list");
System.out.println(array);
if(array.length()>0) {
try {
FoodEntity foodEntity =new FoodEntity();
for(int i=0;i<array.length();i++){
JSONObject object1=array.getJSONObject(i);
foodEntity.setFoodtitle(object1.getString("foodtitle"));
foodEntity.setFoodcontent(object1.getString("foodcontent"));
foodEntity.setFoodcontentimg(object1.getString("foodcontentimg"));
System.out.println(foodEntity.getFoodtitle());
System.out.println(foodEntity.getFoodcontent());
}
} catch (Exception e) {
e.printStackTrace();
}
// 获取到数据后，通知handle刷新UI
Message message = handler.obtainMessage();
message.what = 1;
handler.sendMessage(message);
}else {
Toast.makeText(getActivity(), "无数据", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}*/
for (int i=0;i<10;i++){
FoodEntity foodEntity =new FoodEntity();
foodEntity.setFoodtitle("模拟数据FOOD"+i);
foodEntity.setFoodcontent("100"+i);
goodsEntityList.add(foodEntity);
}
// 获取到数据后，通知handle刷新UI
Message message = handler.obtainMessage();
message.what = 1;
handler.sendMessage(message);
}
}.start();
// for (int i=0;i<10;i++){
// FoodEntity foodEntity =new FoodEntity();
// foodEntity.setName("模拟数据FOOD"+i);
// foodEntity.setContent("100"+i);
// goodsEntityList.add(foodEntity);
// }
}
private void initRecyclerView(View view) {
//获取RecyclerView
mFoodRecyclerView=view.findViewById(R.id.food_recyclerView);
//创建adapter
mRecyclerAdapter = new FoodRecycleAdapter(getActivity(), goodsEntityList);
//给RecyclerView设置adapter
mFoodRecyclerView.setAdapter( mRecyclerAdapter );
//设置layoutManager,可以设置显示效果，是线性布局、grid布局，还是瀑布流布局
//参数是：上下文、列表方向（横向还是纵向）、是否倒叙
mFoodRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));
//设置item的分割线
mFoodRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL));
//RecyclerView中没有item的监听事件，需要自己在适配器中写一个监听事件的接口。参数根据自定义
mRecyclerAdapter.setOnItemClickListener(new FoodRecycleAdapter.OnItemClickListener() {
@Override
public void OnItemClick(View view, FoodEntity data) {
Toast.makeText(getActivity(),"我是item",Toast.LENGTH_SHORT).show();
changeToAnotherFragment();
}
});
}
@SuppressLint("ResourceType")
private void changeToAnotherFragment() {
changeFoodFragment.changeFoodFragment();
}
}