列表视图上的媒体播放器问题

Question

我想在单击按钮时播放声音，我有不同的声音，我用列表视图列出声音，当我在列表视图上选择项目时，单列表项打开布局，我单击单列表项布局上的按钮，但是单击时应用程序正在关闭，它不起作用，问题出在哪里，谢谢

AndroidListViewActivity.class（用于列表和选择项）

单个列表项.class（显示所选项）

按钮单击（在"单列表项"布局上，播放所选声音）

日志猫消息：

11-11 16:18:09.285: E/dalvikvm(17161): VM aborting
11-11 16:18:09.285: A/libc(17161): Fatal signal 11 (SIGSEGV) at 0xdeadd00d (code=1)

AndroidListViewActivity 类;

public class AndroidListViewActivity extends ListActivity {
    int [] sounds;
 MediaPlayer mediaPlayer;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
sounds= new int[] {R.raw.sound1,R.raw.sound2,R.raw.sound3,R.raw.sound4,R.raw.sound5};        
    // storing string resources into Array
    String[] sounds= getResources().getStringArray(R.array.sounds);        
    // Binding Array to ListAdapter
    this.setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, R.id.label,   sounds));
    ListView lv = getListView();
    // listening to single list item on click
    lv.setOnItemClickListener(new OnItemClickListener() {
      public void onItemClick(AdapterView<?> parent, View view,
          int position, long id) {     
          // selected item 
          String selectedsound= ((TextView) view).getText().toString();
          String selectedFromList = getItemAtPosition(position);
            @SuppressWarnings("unused")
            int resId = getResources().getIdentifier(selectedFromList, "raw", getPackageName());
  // Launching new Activity on selecting single List Item
          Intent i = new Intent(getApplicationContext(), SingleListItem.class);
          Intent intent = new Intent(getApplicationContext(), SingleListItem.class);
          // sending data to new activity
          i.putExtra("selectedsound", selectedsound);
          intent.putExtra("position", position);
          startActivity(i);
          startActivity(intent);            
      }
    private String getItemAtPosition(int position) {
        // TODO Auto-generated method stub
        return null;
    }
    });
}
}

单列表项类;

public class SingleListItem extends Activity{
 int [] sounds;
 MediaPlayer mediaPlayer;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    sounds= new int[]   {R.raw.sound1,R.raw.sound2,R.raw.sound3,R.raw.sound4,R.raw.sound5};
           this.setContentView(R.layout.single_list_item_view);
    TextView txtProduct = (TextView) findViewById(R.id.product_label);
    Intent i = getIntent();
    Intent intent = getIntent();
    // getting attached intent data
    String product = i.getStringExtra("selectedsound");
    int position = intent.getExtras().getInt("position");
    // displaying selected sound
    txtProduct.setText(selectedsound);
    mediaPlayer = MediaPlayer.create(this, sounds[position]); 
    Button b = (Button) findViewById(R.id.button1);
    b.setOnClickListener(new View.OnClickListener(){
     public void onClick(View arg0) {                            
    mediaPlayer.start();   
    //start the progress dialog
     }
    }); 
 }    
}

Answer 1

删除resId（您已经没有使用它），因为您正在向其传递Null：

String selectedFromList = getItemAtPosition(position);
int resId = getResources().getIdentifier(selectedFromList, "raw", getPackageName());
private String getItemAtPosition(int position) {
    // TODO Auto-generated method stub
    return null;
}