Question

我想在ListView中添加一个按钮来播放声音。问题是IDE（在List.java中）无法解析此方法 mediaPlayer.create(this,R.raw.people);

MainActivity.java代码

public class MainActivity extends AppCompatActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
        ArrayList<String> list = new ArrayList<String>();
        list.add("item1");


        //instantiate custom adapter
        List adapter = new List(list, this);

        //handle listview and assign adapter
        ListView lView = (ListView)findViewById(R.id.listView);
        lView.setAdapter(adapter);
    }
}

List.java代码：

public class List extends BaseAdapter implements ListAdapter {
    private ArrayList<String> list = new ArrayList<String>();
    private Context context;
     MediaPlayer mediaPlayer;


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

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

    @Override
    public Object getItem(int pos) {
        return list.get(pos);
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.activity_list, null);
        }

        //Handle TextView and display string from your list
        TextView listItemText = (TextView)view.findViewById(R.id.list_item_string);
        listItemText.setText(list.get(position));

        //Handle buttons and add onClickListeners

        Button addBtn = (Button)view.findViewById(R.id.add_btn);


        addBtn.setOnClickListener(new View.OnClickListener(){


            @Override
            public void onClick(View v) {
                    mediaPlayer.create(this,R.raw.people);
                        mediaPlayer.start();
                notifyDataSetChanged();
            }
        });

        return view;
    }
}

Answer 1

方法签名为MediaPlayer create (Context context, int resid)

View.OnClickListener不是Context，在这种情况下this就是BaseAdapter。 Context也不是MediaPlayer.create(List.this.context, R.raw.people)。

您可以使用{{1}}

在适配器中声明它

如何使用按钮与ListView播放声音？

1 个答案: