一个简单的实时麦克风音频表中的Android

Question

我从书临Android的媒体帮助...

下面是代码：

public class MicMeter extends Activity implements OnClickListener { 


RecordAudio recordTask; 
int blocksize = 256; 
int frequency = 8000; 
int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO; 
int audioEncoding = AudioFormat.ENCODING_PCM_16BIT; 
TextView txt; 
Button start; 
boolean started = false; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_mic_meter); 
    start = (Button)findViewById(R.id.button1); 
    txt = (TextView)findViewById(R.id.textView1); 

    start.setOnClickListener(this); 


} 


private class RecordAudio extends AsyncTask <Void,double[],Void>{ 

    @Override 
    protected Void doInBackground(Void... params) { 
     try{ 
     int bufferSize = AudioRecord.getMinBufferSize(frequency,channelConfig,audioEncoding); 
     AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency, channelConfig, audioEncoding, bufferSize); 

     short[] buffer = new short[blocksize]; 
     double[] meter = new double[blocksize]; 

     audioRecord.startRecording(); 

     while(started){ 
      int bufferReadResult = audioRecord.read(buffer, 0, blocksize); 

      for (int i = 0; i < blocksize && i < bufferReadResult; i++) { 
       meter[i] = (double) buffer[i]/32768.0; // signed 16 bit 
      } 
      publishProgress(meter); 
     } 
     audioRecord.stop(); 

    }catch (Throwable t) { 
     Log.e("AudioRecord","RecordingFail"); 
    } 

     return null; 
    } 

    @Override 
    protected void onProgressUpdate(double[]... meter) { 

     for(int i = 0 ; i < meter[0].length ; i++){ 
      double[] helper = meter[i]; 
      txt.setText(Double.toString(helper)); 
     } 

    } 


} 


@Override 
public void onClick(View v) { 
    // TODO Auto-generated method stub 

    if(started){ 
     recordTask.cancel(true); 
    }else{ 
     started = true; 
     recordTask = new RecordAudio(); 
     recordTask.execute(); 

    } 
} 

}

而我按下按钮。 它显示255.0，然后它不响应... 有没有什么办法可以解决它？ 有没有关于此的任何问题版本？

感谢

Answer 1

for(int i = 0 ; i < meter[0].length ; i++){ 
    double helper = i; 
    txt.setText(Double.toString(helper)); 

的setText覆盖旧值。所以只有最后一个电话会显示。最后一次调用将其设置为助手，该助手始终为meter [0] .length。由于这是一个固定的数字，它不会改变。