在下面的代碼中，我的audioRecord對(duì)象沒(méi)有初始化。我嘗試將其移動(dòng)到該onCreate方法并使其成為全局的。我已記錄狀態(tài)，并返回一個(gè)值1，表示可以使用。調(diào)試器表示startRecording正在未初始化的對(duì)象上調(diào)用它。它還說(shuō)它無(wú)法獲得音頻源。為什么我會(huì)收到這些錯(cuò)誤？    package com.tecmark;    import java.io.BufferedOutputStream;    import java.io.DataOutputStream;    import java.io.File;    import java.io.FileOutputStream;    import android.app.Activity;    import android.media.AudioFormat;    import android.media.AudioRecord;    import android.media.MediaRecorder;    import android.os.Bundle;    import android.os.Environment;    import android.util.Log;    import android.view.View;    import android.widget.TextView;    public class recorder extends Activity  {        private Thread thread;        private boolean isRecording;        private AudioRecord recorder;        private FileOutputStream os;        private BufferedOutputStream bos;        private DataOutputStream dos;        private TextView text;        private int audioSource = MediaRecorder.AudioSource.MIC;        private int sampleRate = 22050;        private int channel = AudioFormat.CHANNEL_CONFIGURATION_MONO;        private int encoding = AudioFormat.ENCODING_PCM_16BIT;        private int result = 0;        private int bufferSize;        private byte[] buffer;        /** Called when the activity is first created. */        @Override        public void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            setContentView(R.layout.main);            Log.v("onCreate", "layout set, about to init audiorec obj");            text = (TextView)findViewById(R.id.TextView01);             bufferSize = AudioRecord.getMinBufferSize(sampleRate,channel,encoding);             buffer = new byte[bufferSize];            recorder = new AudioRecord(audioSource, sampleRate,channel,encoding,                    AudioRecord.getMinBufferSize(sampleRate, channel,encoding));            Log.i("recorder obj state",""+recorder.getRecordingState());        }