问题描述
我正在尝试创建NBA球队的回收视图列表，当单击每个球队时，它将显示该特定球队的NBA球员的回收视图视图列表。为此，我构建了我的主要活动，它将在OnCreate方法中启动“ NBA_Adapter”，如下所示：
package com.example.nba;
public class MainActivity extends AppCompatActivity implements SearchView.OnQueryTextListener {
state state = new state();
private NBA_Adapter adapter;
private RecyclerView recyclerView;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu,menu);
MenuItem searchItem = menu.findItem(R.id.action_search);
SearchView searchView = (SearchView) searchItem.getActionView();
searchView.setonQueryTextListener(this);
return true;
}
@Override
public void onCreate(Bundle savedInstanceState) {//originally 'protected'
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recycler_view);
adapter = new NBA_Adapter(getApplicationContext());
recyclerView.setLayoutManager(new linearlayoutmanager(this,linearlayoutmanager.VERTICAL,false));
}
}
NBA_Adapter：
package com.example.nba;
public class NBA_Adapter extends RecyclerView.Adapter<NBA_Adapter.NBAViewHolder> implements Filterable {
public static class NBAViewHolder extends RecyclerView.ViewHolder { //constructer for recyclerview adapter
public LinearLayout containerView;
public TextView textView;
NBAViewHolder(View view) {
super(view);
containerView = view.findViewById(R.id.nba_row);
textView = view.findViewById(R.id.nba_row_text_view);
containerView.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
TEAMS current = (TEAMS) containerView.getTag();
Intent intent = new Intent(v.getContext(),SecondMain.class);
intent.putExtra("id",current.getId());
v.getContext().startActivity(intent);
}
});
}
}
}
第二主要：
public class SecondMain extends AppCompatActivity implements SearchView.OnQueryTextListener {
private int team_id;
private Player_Adapter rapter;
private RecyclerView mrecyclerView;
private RecyclerView.LayoutManager layoutManager;
@Override
public void onCreate(Bundle savedInstanceState) {//originally 'protected'
Log.v("cs100","I exist!");
team_id = getIntent().getIntExtra("id",0);
Log.v("cs100","" + team_id);
super.onCreate(savedInstanceState);
setContentView(R.layout.second_main);
mrecyclerView = findViewById(R.id.mrecycler_view);
rapter = new Player_Adapter(getApplicationContext());
mrecyclerView.setLayoutManager(new linearlayoutmanager(this,false));
state.setstate(false);
mrecyclerView.setAdapter(rapter);
}
}
Android清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.nba">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".SecondMain">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
现在，我可以启动“ SecondMain”类，这是Log.v语句打印的明显证明（这是在此刻，团队而不是团队中的球员正在显示）。由于“ MainActivity”与“ SecondMain”几乎相同，因此我假定类似于“ MainActivity”启动“ NBA_Adapter”的方式，因此“ SecondMain”启动“ Player_Adapter”的方式。 Player_Adapter几乎与“ NBA_Adapter”相同，但根本没有启动。这就是为什么我怀疑问题是我在Android清单中描述“ SecondMain”的原因。我只包括每个课程的相关部分。感谢您提供有关此问题的任何提示或链接！
编辑：以下包含的Player_Adapter类：
public class Player_Adapter extends RecyclerView.Adapter<Player_Adapter.PlayerViewHolder> implements Filterable {
private int team_id;
public class myclass extends AppCompatActivity{
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
team_id = getIntent().getIntExtra("id",0);
recyclerView.setAdapter(adapter);
Log.v("Player",""+ team_id); //Not displaying statement which indicates that "Player_Adapter" is not being launched
}
}
public static class PlayerViewHolder extends RecyclerView.ViewHolder {
public LinearLayout containerView;
public TextView textView;
PlayerViewHolder(View view) {
super(view);
containerView = view.findViewById(R.id.Player_List_row);
textView = view.findViewById(R.id.Player_List_row_text_view);
containerView.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Players current = (Players) containerView.getTag();
Intent intent = new Intent(v.getContext(),Compare_Stats.class);
//we get the "fullName"
intent.putExtra("id",current.getPlayer_id());
v.getContext().startActivity(intent);
}
});
}
}
@NonNull
@Override
public PlayerViewHolder onCreateViewHolder(@NonNull ViewGroup parent,int viewType) {
final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.player_list,parent,false);
return new PlayerViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull PlayerViewHolder holder,int position) {
Players current = PlayersList.get(position);
holder.textView.setText(current.FullName());
holder.containerView.setTag(current);
}
@Override
public int getItemCount() {
return PlayersList.size();
}
}
解决方法
在类myclass中，您肯定是在设置适配器，但似乎缺少将LayoutManager设置为RecyclerView的代码。
recyclerView.setLayoutManager(new LinearLayoutManager(this/*Context here*/));
另一个建议是，您应该单独保留活动，而不要将其嵌套在适配器中。