android AudioTrack不能播放awr(2)

        btnStart = (Button)this.findViewById(R.id.btn_start); 

        btnStop = (Button)this.findViewById(R.id.btn_stop); 

        btnPlay = (Button)this.findViewById(R.id.btn_play); 

        btnFinish = (Button)this.findViewById(R.id.btn_finish); 

        btnFinish.setText("停止播放"); 

        btnPlay.setEnabled(false); 

        btnFinish.setEnabled(false); 

        btnStart.setOnClickListener(this); 

        btnStop.setOnClickListener(this); 

        btnPlay.setOnClickListener(this); 

        btnFinish.setOnClickListener(this); 

//      File fpath = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/11"); 

//      fpath.mkdirs(); 

        try { 

            //audioFile = File.createTempFile("test", ".pcm", fpath); 

            audioFile = new File("/mnt/sdcard/1.pcm"); 

        } catch (Exception e) { 

            // TODO Auto-generated catch block 

            e.printStackTrace(); 

        }        

    } 

    public void onClick(View v){ 

        int id = v.getId(); 

        switch(id){ 

        case R.id.btn_start: 

            recorder = new RecordTask(); 

            recorder.execute(); 

            break; 

        case R.id.btn_stop: