我的应用程序应该采用字符串数组并在RecyclerView中查看它。一切似乎都没问题,但当我运行应用程序时,它什么也没显示!
首先,我在String.xml文件中声明一个名为“array_countries”的String数组
此字符串文件
<resources>
<string name="app_name">StringArrayWithRecyclerView</string>
<string-array name="array_countries">
<item>Australia</item>
<item>Canada</item>
<item>Cambodia</item>
<item>China</item>
<item>England</item>
<item>France</item>
<item>Japan</item>
<item>Rusia</item>
<item>USA</item>
</string-array>
countries_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Dummy"
android:textSize="30sp"
android:textColor="@color/black"
/>
</LinearLayout>
然后我创建 CountriesAdapter
package pro.cs_is.com.stringarraywithrecyclerview;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Collections;
import java.util.List;
public class CountriesAdapter extends RecyclerView.Adapter<CountriesAdapter.CountriesHolder> {
private List<String> list = Collections.emptyList();
private Context context;
public CountriesAdapter(Context context, List list) {
this.context = context;
this.list = list;
}
@Override
public CountriesHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.countries_row, parent, false);
CountriesHolder holder = new CountriesHolder(view);
return holder;
}
@Override
public void onBindViewHolder(final CountriesHolder holder, int position) {
String country = list.get(position);
holder.textView.setText(country);
holder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast toast = Toast.makeText(context, "You clicked " +
holder.textView.getText(), Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
}
});
}
@Override
public int getItemCount() {
return list.size();
}
class CountriesHolder extends RecyclerView.ViewHolder {
TextView textView;
public CountriesHolder(View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.textView);
}
}
}
最后是 MainActivity
package pro.cs_is.com.stringarraywithrecyclerview;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private CountriesAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<String> countries = Arrays.asList(getResources().getStringArray(R.array.array_countries));
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
adapter = new CountriesAdapter(this, countries);
adapter.notifyDataSetChanged();
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
DividerItemDecoration dividerItemDecoration =
new DividerItemDecoration(recyclerView.getContext(), linearLayoutManager.getOrientation());
recyclerView.addItemDecoration(dividerItemDecoration);
recyclerView.setAdapter(adapter);
}
}
答案 0 :(得分:2)
您忘了添加
recyclerView.setLayoutManager(linearLayoutManager);