Java 填充的RecyclerView为空
数据模型:Java 填充的RecyclerView为空,java,android,xml,Java,Android,Xml,数据模型: public class Information { String title;} 适配器: import android.content.Context; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.I
public class Information {
String title;}
适配器:
import android.content.Context;
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 java.util.Collections;
import java.util.List;
/**
* Created by anish on 29/12/14.
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private LayoutInflater inflator;
List<Information> data = Collections.emptyList();
public MyAdapter(Context context, List<Information> data)
{
inflator = LayoutInflater.from(context);
this.data=data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflator.inflate(R.layout.custom_row, parent, false);
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Information current = data.get(position);
holder.text.setText(current.title);
}
@Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView text;
public MyViewHolder(View itemView) {
super(itemView);
text = (TextView) itemView.findViewById(R.id.listText);
}
}
}
导入android.content.Context;
导入android.support.v7.widget.RecyclerView;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ImageView;
导入android.widget.TextView;
导入java.util.Collections;
导入java.util.List;
/**
*由anish于2014年12月29日创作。
*/
公共类MyAdapter扩展了RecyclerView.Adapter{
私人充气机;
List data=Collections.emptyList();
公共MyAdapter(上下文、列表数据)
{
充气器=从(上下文)开始充气;
这个。数据=数据;
}
@凌驾
公共MyViewHolder onCreateViewHolder(视图组父级,int-viewType){
视图=充气机。充气(R.layout.custom_行,父项,false);
MyViewHolder=新的MyViewHolder(视图);
报税表持有人;
}
@凌驾
公共无效onBindViewHolder(MyViewHolder,int位置){
信息当前=数据获取(位置);
holder.text.setText(当前名称);
}
@凌驾
public int getItemCount(){
返回data.size();
}
类MyViewHolder扩展了RecyclerView.ViewHolder{
文本查看文本;
公共MyViewHolder(查看项目视图){
超级(项目视图);
text=(TextView)itemView.findViewById(R.id.listText);
}
}
}
导航抽屉片段:
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
/**
* A simple {@link Fragment} subclass.
*/
public class NavigationDrawerFragment extends Fragment {
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private boolean mUserLearnedDrawer;
private boolean mFromSavedInstanceState;
public static final String PREF_FILE_NAME="testpref";
public static final String KEY_USER_LEARNED_DRAWER="user_learned_drawer";
private View containerView;
private MyAdapter adapter;
public NavigationDrawerFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mUserLearnedDrawer = Boolean.getBoolean(readFromPreferences(getActivity(),KEY_USER_LEARNED_DRAWER,"false"));
if(savedInstanceState!=null) mFromSavedInstanceState = true;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
recyclerView = (RecyclerView) layout.findViewById(R.id.drawer_list);
adapter = new MyAdapter(getActivity(),getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
// Inflate the layout for this fragment
return layout;
}
public static List<Information> getData()
{
List<Information> data = new ArrayList<>();
//int icons[]={R.drawable.abc_ic_ab_back_mtrl_am_alpha, R.drawable.abc_ab_share_pack_holo_dark, R.drawable.abc_btn_radio_to_on_mtrl_000};
String[] title = {"Microsoft","Yahoo","Google"};
for(int i=0; i<title.length; i++)
{
Information current = new Information();
//current.iconId = icons[i];
current.title = title[i];
data.add(current);
}
return data;
}
public void setUp(int fragmentID, DrawerLayout drawerLayout, final Toolbar toolbar) {
containerView = getActivity().findViewById(fragmentID);
mDrawerLayout = drawerLayout;
mDrawerToggle=new ActionBarDrawerToggle(getActivity(),drawerLayout,toolbar, R.string.drawer_open, R.string.drawer_close) {
@Override
public void onDrawerOpened(View drawerView) {
if(!mUserLearnedDrawer)
{
mUserLearnedDrawer=true;
saveToPreferences(getActivity(),KEY_USER_LEARNED_DRAWER,mUserLearnedDrawer+"");
}
getActivity().invalidateOptionsMenu();
super.onDrawerOpened(drawerView);
}
@Override
public void onDrawerClosed(View drawerView) {
getActivity().invalidateOptionsMenu();
super.onDrawerClosed(drawerView);
}
@Override
public void onDrawerSlide(View drawerView, float slideOffset) {
if(slideOffset<0.6)
{
toolbar.setAlpha(1-slideOffset);
}
}
};
if(!mUserLearnedDrawer && !mFromSavedInstanceState)
{
mDrawerLayout.openDrawer(containerView);
}
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mDrawerToggle.syncState();
}
});
}
public static void saveToPreferences(Context context, String preferenceName, String preferenceValue)
{
SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(preferenceName, preferenceValue);
editor.apply();
}
public static String readFromPreferences(Context context, String preferenceName, String defaultValue)
{
SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
return sharedPreferences.getString(preferenceName, defaultValue);
}
}
导入android.content.Context;
导入android.content.SharedReferences;
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.support.v4.widget.DrawerLayout;
导入android.support.v7.app.ActionBarDrawerToggle;
导入android.support.v7.widget.LinearLayoutManager;
导入android.support.v7.widget.RecyclerView;
导入android.support.v7.widget.Toolbar;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入java.util.ArrayList;
导入java.util.List;
/**
*一个简单的{@link Fragment}子类。
*/
公共类NavigationDrawerFragment扩展了片段{
私人回收站;
私有操作bardrawertoggle mDrawerToggle;
私人抽屉布局mDrawerLayout;
私有布尔mUserLearnedDrawer;
私有布尔值mFromSavedInstanceState;
公共静态最终字符串PREF_FILE_NAME=“testpref”;
公共静态最终字符串键\u USER\u LEARNED\u DRAWER=“USER\u LEARNED\u DRAWER”;
私有视图容器视图;
专用MyAdapter适配器;
公共导航抽屉碎片(){
//必需的空公共构造函数
}
@凌驾
创建时的公共void(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mUserLearnedDrawer=Boolean.getBoolean(readFromPreferences(getActivity(),KEY\u USER\u LEARNED\u DRAWER,“false”);
如果(savedInstanceState!=null)mFromSavedInstanceState=true;
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
视图布局=充气机。充气(R.layout.fragment\u navigation\u抽屉、容器,错误);
recyclerView=(recyclerView)layout.findViewById(R.id.drawer\u列表);
adapter=newmyadapter(getActivity(),getData());
recyclerView.setAdapter(适配器);
setLayoutManager(新的LinearLayoutManager(getActivity());
//为该碎片膨胀布局
返回布局;
}
公共静态列表getData()
{
列表数据=新的ArrayList();
//int icons[]={R.drawable.abc_ic_ab_back_mtrl_am_alpha,R.drawable.abc_ab_share_pack_holo_dark,R.drawable.abc_btn_radio_to_on_mtrl_000};
String[]title={“微软”、“雅虎”、“谷歌”};
对于(int i=0;i您的模型中存在问题。您应该在模型类中使用getter和setter方法。以下代码可能会对您有所帮助
public class Information {
private String title;
public Model( String title) {
super();
this.title = title;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
在MainActivity.java中,在MainActivity中设置标题在我的例子中,我意识到适配器的getItemCount()
方法从未被调用。在这种情况下,设置recyclerView的layoutmanager解决了我的问题
recyclerView.layoutManager = LinearLayoutManager(mainActivity)
在getItemCount()中添加一些日志。d做到了这一点,getCount()的值是3,正如预期的那样。BindViewHolder调用了三次?尝试运行hierarchyviewer?是的,它调用了三次。hierarchyviewer显示了什么?为什么这样做?添加getter和setter将如何改变问题?我这样做,但对我不起作用:/
recyclerView.layoutManager = LinearLayoutManager(mainActivity)