电话录音无法开启
mediaRecorder = new MediaRecorder();
String FileName=(this.taskno+System.currentTimeMillis() + ".3gp");
audioFile = new File(Environment.getExternalStorageDirectory(), FileName);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); //获得声音数据源
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); // 按3gp格式输出
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); //音频编码方式
mediaRecorder.setOutputFile(audioFile.getAbsolutePath()); //输出文件
mediaRecorder.prepare(); //准备
mediaRecorder.start();
报java.lang.RuntimeException: start failed.错误