Java 数据未绑定到android recyclerview
我是android新手。我试图使用Github api下载数据,并在无限滚动的RecyclerView中显示,JSON数据已被解析,但不知何故,数据并未附加到RecyclerView。 代码如下:Java 数据未绑定到android recyclerview,java,android,json,android-volley,Java,Android,Json,Android Volley,我是android新手。我试图使用Github api下载数据,并在无限滚动的RecyclerView中显示,JSON数据已被解析,但不知何故,数据并未附加到RecyclerView。 代码如下: Developer_RV_Adapter.java package com.davidshare.githubdevelopers; import android.content.Context; import android.content.Intent; import android.suppo
Developer_RV_Adapter.java
package com.davidshare.githubdevelopers;
import android.content.Context;
import android.content.Intent;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.List;
/**
* Created by GemShare on 9/6/2017.
*/
public class Developer_RV_Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final int VIEW_TYPE_ITEM = 0;
private final int VIEW_TYPE_LOADING = 1;
private OnLoadMoreListener mOnLoadMoreListener;
private boolean isLoading;
private int visibleThreshold = 10;
private int lastVisibleItem, totalItemCount;
private List<Developer> developerList;
Context context;
RecyclerView recyclerView;
public Developer_RV_Adapter(Context context, List<Developer> developerList, RecyclerView recyclerView) {
this.developerList = developerList;
this.context = context;
this.recyclerView = recyclerView;
final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
if(!isLoading && totalItemCount<=(lastVisibleItem+visibleThreshold)){
if(mOnLoadMoreListener!=null){
mOnLoadMoreListener.onLoadMore();
}
isLoading = true;
}
}
});
}
public void setmOnLoadMoreListener(OnLoadMoreListener mOnLoadMoreListener){
this.mOnLoadMoreListener = mOnLoadMoreListener;
}
@Override
public int getItemViewType(int position){
return developerList.get(position) == null? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if(viewType == VIEW_TYPE_ITEM){
View developerView = LayoutInflater.from(context).inflate(R.layout.developer_list_item, parent, false);
return new DeveloperViewHolder(developerView);
}else if(viewType== VIEW_TYPE_LOADING){
View loadingView = LayoutInflater.from(context).inflate(R.layout.progress_bar_item, parent, false);
return new ProgressViewHolder(loadingView);
}
return null;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
Log.w("binder function", "Just entered the binder");
Developer developer = developerList.get(position);
if(holder instanceof DeveloperViewHolder){
DeveloperViewHolder developerViewHolder = (DeveloperViewHolder) holder;
developerViewHolder.gitNameTv.setText(developer.getGitUsername());
Log.w("binder ", developer.getGitProfileUrl());
developerViewHolder.gitUrlTv.setText(developer.getGitProfileUrl());
developerViewHolder.gitPicUrlTv.setText(developer.getGitProfilePicUrl());
Log.w("profile pic", developer.getGitProfilePicUrl());
Picasso.with(developerViewHolder.gitNameTv.getContext()).load(developer.getGitProfilePicUrl()).transform(new RoundedImage(2)).fit().centerCrop().into(developerViewHolder.profilePicImgV);
}else if (holder instanceof ProgressViewHolder) {
ProgressViewHolder loadingViewHolder = (ProgressViewHolder) holder;
loadingViewHolder.loadingProgress.setIndeterminate(true);
}
}
@Override
public int getItemCount() {
return developerList == null ? 0 : developerList.size();
}
public void setLoaded() {
isLoading = false;
}
public class DeveloperViewHolder extends RecyclerView.ViewHolder{
TextView gitNameTv;
TextView gitUrlTv;
ImageView profilePicImgV;
TextView gitPicUrlTv;
public DeveloperViewHolder(final View itemView) {
super(itemView);
gitNameTv = (TextView) itemView.findViewById(R.id.developerName);
gitUrlTv = (TextView) itemView.findViewById(R.id.developerUrl);
profilePicImgV = (ImageView) itemView.findViewById(R.id.developerPic);
gitPicUrlTv = (TextView) itemView.findViewById(R.id.developerPicUrl);
itemView.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
Intent i = new Intent(itemView.getContext(), Profile.class);
i.putExtra("profile_name", gitNameTv.getText().toString());
i.putExtra("profile_url", gitUrlTv.getText().toString());
i.putExtra("profile_pic_url", gitPicUrlTv.getText().toString());
v.getContext().startActivity(i);
}
});
}
}
public static class ProgressViewHolder extends RecyclerView.ViewHolder{
public ProgressBar loadingProgress;
public ProgressViewHolder(View itemView) {
super(itemView);
loadingProgress = (ProgressBar) itemView.findViewById(R.id.loading_progress_bar);
}
}
}
DeveloperList.java
package com.davidshare.githubdevelopers;
import android.app.ProgressDialog;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class DeveloperList extends AppCompatActivity {
List<Developer> developerList;
Developer_RV_Adapter developer_rv_adapter;
Developer developer;
RecyclerView developerRV;
private static final String GIT_BASE_URL = "https://api.github.com/search/users?q=location:";
private static int page = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_developer_list);
developerRV = (RecyclerView) findViewById(R.id.developer_rv);
developerRV.setLayoutManager(new LinearLayoutManager(this));
developerList = new ArrayList<>();
getDevelopersData(prepareQuery("java", "lagos", page));
developer_rv_adapter = new Developer_RV_Adapter(DeveloperList.this, developerList, developerRV);
developerRV.setAdapter(developer_rv_adapter);
developer_rv_adapter.setmOnLoadMoreListener(new OnLoadMoreListener() {
@Override
public void onLoadMore() {
developerList.add(null);
developer_rv_adapter.notifyItemInserted(developerList.size()-1);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
developerList.remove(developerList.size()-1);
developer_rv_adapter.notifyItemRemoved(developerList.size());
getDevelopersData(prepareQuery("java", "lagos", page));
developer_rv_adapter.notifyDataSetChanged();
developer_rv_adapter.setLoaded();
}
}, 5000);
}
});
}
Developer\u RV\u Adapter.java
包com.davidshare.githubdevelopers;
导入android.content.Context;
导入android.content.Intent;
导入android.support.v7.widget.LinearLayoutManager;
导入android.support.v7.widget.RecyclerView;
导入android.util.Log;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ImageView;
导入android.widget.ProgressBar;
导入android.widget.TextView;
导入com.squareup.picasso.picasso;
导入java.util.List;
/**
*由GemShare于2017年9月6日创建。
*/
公共类开发人员_RV_适配器扩展了RecyclerView.Adapter{
私有最终整数视图\类型\项=0;
私有最终内部视图类型加载=1;
私有OnLoadMoreListener mOnLoadMoreListener;
私有布尔孤岛加载;
私有int visibleThreshold=10;
private int lastVisibleItem,totalItemCount;
私有列表developerList;
语境;
回收视图回收视图;
公共开发人员_RV_适配器(上下文上下文、列表developerList、RecycleView和RecycleView){
this.developerList=developerList;
this.context=上下文;
this.recyclerView=recyclerView;
最终LinearLayoutManager LinearLayoutManager=(LinearLayoutManager)recyclerView.getLayoutManager();
recyclerView.addOnScrollListener(新的recyclerView.OnScrollListener(){
@凌驾
已填空的公共空间(RecyclerView RecyclerView、int dx、int dy){
super.onScrolled(recyclerView、dx、dy);
totalItemCount=linearLayoutManager.getItemCount();
lastVisibleItem=linearLayoutManager.findLastVisibleItemPosition();
如果(!isLoading&&totalItemCount尝试在数据添加到数组列表后在getdeveloperData()中通知适配器,如添加此行developer\u rv\u适配器。notifyDataSetChanged();而不是使用notifyItemInserted()
notifyItemRangedChanged(fromIndex,toIndex);
这将通知适配器整个数据中的某组数据发生了更改,并告知适配器适配器应刷新数据并将其重新加载到recyclerView中,从传递到方法的fromIndex到toIndex
如果所有数据都已更改,则使用:
notifyDataSetChanged();
notifyItemChanged(dataPosition);
如果仅更改了一个数据项,则使用:
notifyDataSetChanged();
notifyItemChanged(dataPosition);
此外,我认为此状态导致了问题。请尝试删除此状态并再次检查
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
developerList.remove(developerList.size()-1);
developer_rv_adapter.notifyItemRemoved(developerList.size());
getDevelopersData(prepareQuery("java", "lagos", page));
developer_rv_adapter.notifyDataSetChanged();
developer_rv_adapter.setLoaded();
}
}, 5000);
只需在developerList.add(developer)下面添加developer_rv_adapter.notifyDataSetChanged();即可解决此问题;这会通知适配器已将新项目添加到列表中。这部分代码没有问题,工作正常无需引用添加处理程序有时会导致问题。.所以我说