ListView未显示数据

Question

我为音频文件创建了一个列表视图，listView没有显示数据 只显示图像3次没有显示音频我不知道我在哪里做错了请帮帮我...

ListActivity

public class MainActivity extends Activity {

Cursor c;
int index;
int count;

   @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ListView listView = (ListView) findViewById(R.id.audio_list);
    String cols[] = {MediaStore.Audio.Media.DISPLAY_NAME,
            MediaStore.Audio.Media.DURATION,
            MediaStore.Audio.Media.DATA
    };
    c = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, cols, null, null, null);
      String imagePath = Environment.getExternalStorageDirectory() + "/audio/recording.3gp`";
    File f=new File(imagePath);
    Uri uri = Uri.fromFile(f);
    List<String> data = new ArrayList<String>();

    for (int i = 0; i < c.getColumnCount(); i++){
       data.add(String.valueOf(f));
    }
    CustomAdapter customAdapter = new CustomAdapter(this,data);
    listView.setAdapter(customAdapter);
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                                long arg3) {
            // TODO Auto-generated method stub
        }
    });
}

适配器

public class CustomAdapter extends BaseAdapter {
    private final Context context;
    private final List<String> items;
    private final Map<View, Map<Integer, View>>
            cache = new HashMap<View, Map<Integer, View>>();

    public CustomAdapter(Context context, List<String> items) {
        this.context = context;
        this.items = items;
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public Object getItem(int position) {
        return items.get(position);
    }

    @Override
    public long getItemId(int position) {
        return getItem(position).hashCode();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        TextView tv;
        ImageView iv;
        if (v == null) {
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = inflater.inflate(R.layout.item, parent, false);
        }
        Map<Integer, View> itemMap = cache.get(v);
        if (itemMap == null) {
            itemMap = new HashMap<Integer, View>();
            tv = (TextView) v.findViewById(android.R.id.text1);
            iv = (ImageView) v.findViewById(R.id.imageView);
            itemMap.put(android.R.id.text1, tv);
            itemMap.put(R.id.imageView, iv);
            cache.put(v, itemMap);
        } else {
            tv = (TextView) itemMap.get(android.R.id.text1);
            iv = (ImageView) itemMap.get(R.id.imageView);
        }
        final String item = (String) getItem(position);
        tv.setText(item);
        iv.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(context,
                        String.format("Image clicked: %s", item),
                        Toast.LENGTH_SHORT).show();
            }
        });
        return v;
    }
}

activity_main.xml中

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView android:layout_height="wrap_content"
    android:id="@android:id/list"
    android:layout_width="match_parent" />

itm.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:minHeight="?android:attr/listPreferredItemHeight"
android:gravity="center_vertical">
<TextView
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:layout_width="wrap_content"
    android:id="@android:id/text1"
    android:layout_height="wrap_content"
    android:layout_weight="1" />
<ImageView android:src="@mipmap/ic_launcher"
    android:layout_width="wrap_content"
    android:id="@+id/imageView"
    android:layout_height="wrap_content"
    android:clickable="true" />

Answer 1

您尚未将任何数据初始化为列出“数据”
你必须在for循环中初始化数据。

List<String> data = new ArrayList<String>();

for (int i = 0; i < c.getColumnCount(); i++){

}
CustomAdapter customAdapter = new CustomAdapter(this,data);

编辑：

用以下代码替换for循环

        if (c!=null && c.moveToFirst()) {
        do{

        String audio_name_with_path = c.getString(2).toString();
        data.add(audio_name_with_path);

        }while(c.moveToNext());
       }