我一直试图让用户录制长达30秒的声音，并使用SeekBar来表示他们到目前为止录制了多少声音。我有一些代码，我从网上的各种指令拼凑而成，但我不断得到一个NPE和“MessageQueue回调中的异常：handleReceiveCallback”/“Exception dispatching input event”错误。我不确定如何解释这个或我做错了什么。通过日志标记，我可以告诉它到达StartRecording（）然后在调用Handler来跟踪记录长度时抛出异常。有谁能看到这个问题？代码如下：
内部AudioRecorder类：
import java.io.File;
import java.io.IOException;
import android.content.Context;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;
public class AudioRecorder {
private static final String LOG_TAG = "AudioRecordTest";
private String fileName = Environment.getExternalStorageDirectory()+"/audio"+System.currentTimeMillis()+".3gp";
private static MediaRecorder mRecorder;
private static MediaPlayer mPlayer;
public boolean isRecording;
public boolean isPlaying;
int recordTime;
Handler handler;
public void onRecord(boolean start) {
if (start) {
startRecording();
} else {
stopRecording();
}
}
public void onPlay(boolean start) {
if (start) {
startPlaying();
} else {
stopPlaying();
}
}
public void startPlaying() {
mPlayer = new MediaPlayer();
try {
mPlayer.setDataSource(fileName);
mPlayer.prepare();
mPlayer.start();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed");
}
isPlaying = true;
}
public void stopPlaying() {
mPlayer.release();
mPlayer = null;
isPlaying = false;
}
public void startRecording() {
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setOutputFile(fileName);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recordTime = 0;
try {
mRecorder.prepare();
} catch (IOException e) {
Log.e(LOG_TAG, "prepare() failed");
}
Log.w("LCC", "Start playing made it this far! 1!");
mRecorder.start();
isRecording = true;
handler.post(UpdateRecordTime);
}
public void stopRecording() {
mRecorder.stop();
mRecorder.reset();
mRecorder = null;
isRecording = false;
handler.removeCallbacks(UpdateRecordTime);
}
public void playSound(Context c){
if (mPlayer == null) {
Uri uri = Uri.parse(fileName);
mPlayer = MediaPlayer.create(c, uri);
mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
public void onCompletion(MediaPlayer mp) {
stopPlayer();
}
});
}
mPlayer.start();
}
public void stopPlayer() {
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
Runnable UpdateRecordTime = new Runnable(){
public void run(){
if(isRecording){
recordTime++;
// Delay 1s before next call
handler.postDelayed(this, 1000);
}
}
};
public int getCurrentPosition(){
return recordTime;
};
}
在AudioRecorderActivity类中：
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.MotionEvent;
import android.view.View;
import android.widget.SeekBar;
public class AudioRecorderActivity extends ActionBarActivity {
private AudioRecorder mRecorder = new AudioRecorder();
//private View mPlayButton;
//private View mStopButton;
//private View mRecordButton;
private View mRecordButton;
private SeekBar mSeekBar;
private boolean isRecording;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
//requestWindowFeature(Window.FEATURE_NO_TITLE);
//getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
// WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_record);
ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
mSeekBar = (SeekBar)findViewById(R.id.SeekBar);
mSeekBar.setMax(30);
mRecordButton = findViewById(R.id.recordPlayButton);
mRecordButton.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
mRecorder.onRecord(true);
isRecording = true;
final Handler mHandler = new Handler();
final Runnable mRunnable = new Runnable() {
@Override
public void run() {
if(mRecorder.isRecording){
int mCurrentPosition = mRecorder.getCurrentPosition() / 1000;
mSeekBar.setProgress(mCurrentPosition);
}
mHandler.postDelayed(this, 1000);
}
};
break;
case MotionEvent.ACTION_UP:
mRecorder.stopRecording();
isRecording = false;
break;
}
return false;
}
});
任何帮助将不胜感激。谢谢!!
编辑：这是确切的错误（按下录制按钮时会出现两组）
02-03 17:17:28.189: W/LCC(3757): Start playing made it this far! 1!
02-03 17:17:28.579: E/InputEventReceiver(3757): Exception dispatching input event.
02-03 17:17:28.579: E/MessageQueue-JNI(3757): Exception in MessageQueue callback: handleReceiveCallback
02-03 17:17:28.599: E/MessageQueue-JNI(3757): java.lang.NullPointerException
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.littlecloudcollective.waves.AudioRecorder.startRecording(AudioRecorder.java:80)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.littlecloudcollective.waves.AudioRecorder.onRecord(AudioRecorder.java:28)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.littlecloudcollective.waves.AudioRecorderActivity$1.onTouch(AudioRecorderActivity.java:43)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.View.dispatchTouchEvent(View.java:7229)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2177)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1482)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.app.Activity.dispatchTouchEvent(Activity.java:2469)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.dispatchTouchEvent(ActionBarActivityDelegateICS.java:260)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2125)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.View.dispatchPointerEvent(View.java:7414)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3523)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3455)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4565)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4543)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4647)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.os.MessageQueue.nativePollOnce(Native Method)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.os.MessageQueue.next(MessageQueue.java:125)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.os.Looper.loop(Looper.java:124)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at android.app.ActivityThread.main(ActivityThread.java:4963)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at java.lang.reflect.Method.invokeNative(Native Method)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at java.lang.reflect.Method.invoke(Method.java:511)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
02-03 17:17:28.599: E/MessageQueue-JNI(3757): at dalvik.system.NativeStart.main(Native Method)
02-03 17:17:28.599: D/AndroidRuntime(3757): Shutting down VM
02-03 17:17:28.599: W/dalvikvm(3757): threadid=1: thread exiting with uncaught exception (group=0x41104438)
02-03 17:17:28.609: E/AndroidRuntime(3757): FATAL EXCEPTION: main
02-03 17:17:28.609: E/AndroidRuntime(3757): java.lang.NullPointerException
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.littlecloudcollective.waves.AudioRecorder.startRecording(AudioRecorder.java:80)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.littlecloudcollective.waves.AudioRecorder.onRecord(AudioRecorder.java:28)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.littlecloudcollective.waves.AudioRecorderActivity$1.onTouch(AudioRecorderActivity.java:43)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.View.dispatchTouchEvent(View.java:7229)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2237)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1936)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2177)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1482)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.app.Activity.dispatchTouchEvent(Activity.java:2469)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.dispatchTouchEvent(ActionBarActivityDelegateICS.java:260)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2125)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.View.dispatchPointerEvent(View.java:7414)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3523)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3455)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4565)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4543)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4647)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.os.MessageQueue.nativePollOnce(Native Method)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.os.MessageQueue.next(MessageQueue.java:125)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.os.Looper.loop(Looper.java:124)
02-03 17:17:28.609: E/AndroidRuntime(3757): at android.app.ActivityThread.main(ActivityThread.java:4963)
02-03 17:17:28.609: E/AndroidRuntime(3757): at java.lang.reflect.Method.invokeNative(Native Method)
02-03 17:17:28.609: E/AndroidRuntime(3757): at java.lang.reflect.Method.invoke(Method.java:511)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
02-03 17:17:28.609: E/AndroidRuntime(3757): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
02-03 17:17:28.609: E/AndroidRuntime(3757): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
您忘了创建Handler的新对象。添加
handler=new Handler();
到AudioRecorder课程，你会没事的。
另外，我认为您在设置值时犯了另一个错误：
getCurrentPosition()将返回0到30之间的值。当您致电getCurrentPosition()/1000时，它在技术上不能超过0，因为int1/int1+int2将始终返回0. Seekbar从注释掉/1000所以它是
int mCurrentPosition = mRecorder.getCurrentPosition();
mSeekBar.setProgress(mCurrentPosition);
你应该没事。
当录音达到30秒标记时， getCurrentPosition()*10/3将使Seekbar达到终点。