Question

我正在制作应用程序，根据麦克风输入的噪音测量风速。将噪音和计算器记录到Decibells工作正常。我想在名为 amptv 的TextView中显示 newAmplitude 的值。它只显示0，因为 newAmplitude 在onCreate上为0。在点击“停止记录”按钮后，如何将TextView的文本更改为 newAmplitude 的值？

由于onclicklistener属于自己的类，我无法使用amptv.setText（newAmplitude）进行操作;

这是我尝试过的最后一件事，也尝试了其他一些事情，但他们也没有成功。

public class vumeter extends Activity {
private static final String LOG_TAG = "AudioRecordTest";
protected static final String TAG = null;
private static String mFileName = null;
private RecordButton mRecordButton = null;
private MediaRecorder mRecorder = null;
private PlayButton mPlayButton = null;
private MediaPlayer mPlayer = null;
private Handler mHandler = new Handler() {
    public void handleMessage(android.os.Message msg) {
        currentAmplitude = mRecorder.getMaxAmplitude();
        Log.i(TAG, "handleMessage : MaxAmplitude : " + currentAmplitude);
        newAmplitude = 20 * Math.log(currentAmplitude);
        Log.i(TAG, "nieuwe amplitude : " + newAmplitude);
    }
};
private Timer timer = new Timer();
private TimerTask timerTask = null;
private int currentAmplitude;
private double newAmplitude = 5.0;
public TextView amptv;

private void onRecord(boolean start) {
    if (start) {
        startRecording();
    } else {
        stopRecording();
    }
}

private void onPlay(boolean start) {
    if (start) {
        startPlaying();
    } else {
        stopPlaying();
    }
}

private void startPlaying() {
    mPlayer = new MediaPlayer();
    try {
        mPlayer.setDataSource(mFileName);
        mPlayer.prepare();
        mPlayer.start();
    } catch (IOException e) {
        Log.e(LOG_TAG, "prepare() failed");
    }
}

private void stopPlaying() {
    mPlayer.release();
    mPlayer = null;
}

private synchronized void startRecording() {
    if (mRecorder == null) {
        mRecorder = new MediaRecorder();
        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        mRecorder.setOutputFile(mFileName);
        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    }

    try {
        mRecorder.prepare();
    } catch (IOException e) {
        Log.e(LOG_TAG, "prepare() failed");
    }

    mRecorder.start();
    timer.schedule(timerTask = new TimerTask() {
        @Override
        public void run() {
            mHandler.sendEmptyMessage(0);
        }
    }, 250, 250);
}

private synchronized void stopRecording() {
    if (timerTask != null) {
        timerTask.cancel();
        timerTask = null;
    }
    mRecorder.stop();
    mRecorder.release();
    mRecorder = null;

}

class RecordButton extends Button {
    boolean mStartRecording = true;

    OnClickListener clicker = new OnClickListener() {
        public void onClick(View v) {
            onRecord(mStartRecording);
            if (mStartRecording) {
                setText("Stop measuring");
            } else {
                setText("Start measuring");

                amptv.setText(newAmplitde);
            }
            mStartRecording = !mStartRecording;
        }
    };

    public RecordButton(Context ctx) {
        super(ctx);
        setText("Start measuring");
        setOnClickListener(clicker);
    }
}

class PlayButton extends Button {
    boolean mStartPlaying = true;

    OnClickListener clicker = new OnClickListener() {
        public void onClick(View v) {
            onPlay(mStartPlaying);
            if (mStartPlaying) {
                setText("Stop playing");
            } else {
                setText("Start playing");
            }
            mStartPlaying = !mStartPlaying;
        }
    };

    public PlayButton(Context ctx) {
        super(ctx);
        setText("Start playing");
        setOnClickListener(clicker);

    }
}

public vumeter() {
    mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
    mFileName += "/audiorecordtest.3gp";
}

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    LinearLayout ll = new LinearLayout(this);
    mRecordButton = new RecordButton(this);
    ll.addView(mRecordButton, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0));
    mPlayButton = new PlayButton(this);
    ll.addView(mPlayButton, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0));
    TextView amptv = new TextView(this);
    ll.addView(amptv, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0));
    amptv.setText(Double.toString(newAmplitude));
    setContentView(ll);
}

@Override
public void onPause() {
    super.onPause();
    if (mRecorder != null) {
        mRecorder.release();
        mRecorder = null;
    }

    if (mPlayer != null) {
        mPlayer.release();
        mPlayer = null;
    }
}

public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.my_options_menu, menu);
    return true;
}

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.help:
        startActivity(new Intent(this, InfoMeter.class));
        return true;

    default:
        return super.onOptionsItemSelected(item);
    }
}

希望有人可以帮助我，我是java的初学者，我真的很困难。

这是我的第二次尝试，当我按下stoprecord按钮时仍然会出错。

class RecordButton extends Button {
    boolean mStartRecording = true;

    OnClickListener clicker = new OnClickListener() {
        public void onClick(View v) {
            onRecord(mStartRecording);
            if (mStartRecording) {
                setText("Stop measuring");
            } else {
                setText("Start measuring");

                vumeter.this.amptv.setText(Double.toString(vumeter.this.newAmplitude));

            }
            mStartRecording = !mStartRecording;
        }
    };

    public RecordButton(Context ctx) {
        super(ctx);
        setText("Start measuring");
        setOnClickListener(clicker);
    }
}

Answer 1

像这样使用你的逻辑。

// (R.id.empty)     Replace with your TextView id.
TextView amptv = (TextView) findViewById(R.id.amptv);
amptv.setText(newAmplitude);

在要设置值的类的单独区域中，创建对象的实例。然后通过setText（）设置值。这对你来说非常合适。

Answer 2

使OnClickListener成为Vumeter的内部类（您应该使用类的大写标识符），然后您可以访问amptv的字段Vumeter，如下所示：

Vumeter.this.amptv.setText( Double.toString(Vumeter.this.newAmplitude) );

this将是OnClickListener，Vumeter.this是Vumeter的外部实例。

另一个类中的setText - Android

2 个答案: