Question

当列表中没有项目时，不会显示空视图。有什么问题？

Main_Activity

package com.example.android.customadapter;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        ArrayList<Players> objects = new ArrayList<>();


        objects.add(new Players("Shikhar Dhawan",R.drawable.shikhar));
        objects.add(new Players("Virat Kohli",R.drawable.kohli));

    }
}

我的模特课

Players.java

package com.example.android.customadapter;

public class Players {

    private String mName;
    private int image;


    Players(String name,int res)
    {
        mName = name;
        image = res;
    }

    public String getName()
    {
        return mName;
    }

    public int getImage()
    {
        return image;
    }
}

CustomAdapter类

package com.example.android.customadapter;

我的自定义数组列表适配器

public class CustomAdapter extends ArrayAdapter<Players> {

    public CustomAdapter(@NonNull Context context, @LayoutRes int resource, @NonNull ArrayList<Players> objects) {
        super(context, resource, objects);
    }


    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        View v = convertView;
        if(v==null)
        {
            v = LayoutInflater.from(getContext()).inflate(R.layout.list_item,parent,false);
        }

        Players p = getItem(position);

        TextView t = (TextView)v.findViewById(R.id.miwok_text_view);

        t.setText(p.getName());

        ImageView i = (ImageView)v.findViewById(R.id.image);

        i.setImageResource(p.getImage());


        return v;
    }

}

Answer 1

从您的activity_main.xml获取listView。他们为该列表设置了适配器。有关详细信息：http://www.journaldev.com/10416/android-listview-with-custom-adapter-example-tutorial

Answer 2

您收到错误是因为您没有从课程中获取该值。这是我使用的代码

 @NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view =convertView;
    LayoutInflater layoutInflater = LayoutInflater.from(getContext());
    if (convertView==null){
        view=layoutInflater.inflate(R.layout.customplaylist,parent,false);
    }
    Playlistfileinfo playlistfileinfo =(Playlistfileinfo)getItem(position);
    TextView textView =(TextView)view.findViewById(R.id.textView7);
    textView.setTypeface(typeface);
    textView.setText(playlistfileinfo.getName());
    return view;
}

你可以看到Playlistfileinfo playlistfileinfo =(Playlistfileinfo)getItem(position);希望这对你有帮助。

Answer 3

我已经在main_activity的ArrayList末尾解决了它在里面。 OnCreate方法中的Listview并将数组适配器设置为listView

CustomAdapter adapter = new CustomAdapter（this，words）;

    ListView listView = (ListView) findViewById(R.id.list);

    listView.setAdapter(adapter);

自定义列表显示空白屏幕未显示

3 个答案: