我刚刚开始,我正在使用开发人员教程。我已将录制代码修改如下,但出现错误,我不确定。我没有深入的 Java 水平,而且我只有大约 3 周的时间来学习对象和类。此应用程序适用于我们没有规范的项目。
private static final String LOG_TAG = "Recording";
//start recording stuff
private RecordButton mRecordButton = null;
private MediaRecorder mRecorder = null;
private void onRecord(boolean start)
{
if (start)
startRecording();
else
stopRecording();
}
private void startRecording()
{
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setOutputFile("/sdCard0/panic_record/" + System.currentTimeMillis()+ ".3gp");
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
try {
mRecorder.prepare();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed");
}
mRecorder.start();
}
private void stopRecording()
{
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 recording");
} else {
setText("Start recording");
}
mStartRecording = !mStartRecording;
}
};
public RecordButton(Context ctx) {
super(ctx);
setText("Start recording");
setOnClickListener(clicker);
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_record);
getActionBar().setDisplayHomeAsUpEnabled(true);
LinearLayout ll = new LinearLayout(this);
mRecordButton = new RecordButton(this);
ll.addView(mRecordButton,
new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT,
0));
setContentView(ll);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_record, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
LogCat 输出为
09-26 20:05:37.620:电子/录音(1152):准备()失败 09-26 20:05:37.620:E/MediaRecorder(1152):在无效状态下开始调用:4 09-26 20:05:37.620: D/AndroidRuntime(1152): 关闭 VM 09-26 20:05:37.620: W/dalvikvm(1152): threadid=1: 线程以未捕获的异常退出 (group=0x41c18300) 09-26 20:05:37.630: E/AndroidRuntime(1152): 致命异常: main 09-26 20:05:37.630: E/AndroidRuntime(1152): java.lang.IllegalStateException 09-26 20:05:37.630: E/AndroidRuntime(1152): at android.media.MediaRecorder.start(Native Method) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 cs4084.panic.button.Record.startRecording(Record.java:55) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 cs4084.panic.button.Record.onRecord(Record.java:34) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 cs4084.panic.button.Record.access$0(Record.java:31) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 cs4084.panic.button.Record$RecordButton$1.onClick(Record.java:71) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.view.View.performClick(View.java:4211) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.view.View$PerformClick.run(View.java:17267) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.os.Handler.handleCallback(Handler.java:615) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.os.Handler.dispatchMessage(Handler.java:92) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.os.Looper.loop(Looper.java:137) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 android.app.ActivityThread.main(ActivityThread.java:4898) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 java.lang.reflect.Method.invokeNative(Native Method) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 java.lang.reflect.Method.invoke(Method.java:511) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006) 09-26 20:05:37.630: E/AndroidRuntime(1152): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773) 09-26 20:05:37.630: E/AndroidRuntime(1152): at dalvik.system.NativeStart.main(Native Method)