这是我的代码，当我打开应用程序时，我试图录制视频，但是当我试图打开应用程序时它会给我错误....... 使用按钮录制视频没有问题但是当我添加（启动时）方法时它就开始了 给我这个错误......
private Camera myCamera;
private MyCameraSurfaceView myCameraSurfaceView;
private MediaRecorder mediaRecorder;
Button myButton;
SurfaceHolder surfaceHolder;
boolean recording;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
recording = false;
setContentView(R.layout.main);
//Get Camera for preview
myCamera = getCameraInstance();
if(myCamera == null){
Toast.makeText(AndroidVideoCapture.this,
"Fail to get Camera",
Toast.LENGTH_LONG).show();
}
myCameraSurfaceView = new MyCameraSurfaceView(this, myCamera);
FrameLayout myCameraPreview = (FrameLayout)findViewById(R.id.videoview);
myCameraPreview.addView(myCameraSurfaceView);
myButton = (Button)findViewById(R.id.mybutton);
myButton.setOnClickListener(myButtonOnClickListener);
}
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
if(!prepareMediaRecorder()){
mediaRecorder.start();
}
}
Button.OnClickListener myButtonOnClickListener
= new Button.OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(recording){
// stop recording and release camera
mediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
//Exit after saved
finish();
}else{
//Release Camera before MediaRecorder start
releaseCamera();
if(!prepareMediaRecorder()){
Toast.makeText(AndroidVideoCapture.this,
"Fail in prepareMediaRecorder()!\n - Ended -",
Toast.LENGTH_LONG).show();
finish();
}
mediaRecorder.start();
recording = true;
myButton.setText("STOP");
}
}};
private Camera getCameraInstance(){
// TODO Auto-generated method stub
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
private boolean prepareMediaRecorder(){
myCamera = getCameraInstance();
mediaRecorder = new MediaRecorder();
myCamera.unlock();
mediaRecorder.setCamera(myCamera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mediaRecorder.setOutputFile("/sdcard/myvideo.mp4");
mediaRecorder.setMaxDuration(6000); // Set max duration 60 sec.
mediaRecorder.setMaxFileSize(5000000); // Set max file size 5M
mediaRecorder.setPreviewDisplay(myCameraSurfaceView.getHolder().getSurface());
try {
mediaRecorder.prepare();
} catch (IllegalStateException e) {
releaseMediaRecorder();
return false;
} catch (IOException e) {
releaseMediaRecorder();
return false;
}
return true;
}
@Override
protected void onPause() {
super.onPause();
releaseMediaRecorder(); // if you are using MediaRecorder, release it first
releaseCamera(); // release the camera immediately on pause event
}
private void releaseMediaRecorder(){
if (mediaRecorder != null) {
mediaRecorder.reset(); // clear recorder configuration
mediaRecorder.release(); // release the recorder object
mediaRecorder = null;
myCamera.lock(); // lock camera for later use
}
}
private void releaseCamera(){
if (myCamera != null){
myCamera.release(); // release the camera for other applications
myCamera = null;
}
}
public class MyCameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback{
private SurfaceHolder mHolder;
private Camera mCamera;
public MyCameraSurfaceView(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int weight,
int height) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// make any resize, rotate or reformatting changes here
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}
}
这是我的logcat：
01-30 07：42：20.244：D / AndroidRuntime（267）：关闭虚拟机
01-30 07：42：20.244：W / dalvikvm（267）：threadid = 1：线程退出时未捕获异常（组= 0x4001d800）
01-30 07：42：20.254：E / AndroidRuntime（267）：致命异常：主
01-30 07：42：20.254：E / AndroidRuntime（267）：java.lang.RuntimeException：无法启动活动 ComponentInfo {com.exercise.AndroidVideoCapture / com.exercise.AndroidVideoCapture.AndroidVideoCapture}：java.lang.NullPointerException
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2663）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2679）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread.access $ 2300（ActivityThread.java:125）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:2033）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.os.Handler.dispatchMessage（Handler.java:99）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.os.Looper.loop（Looper.java:123）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread.main（ActivityThread.java:4627）
01-30 07：42：20.254：E / AndroidRuntime（267）：at java.lang.reflect.Method.invokeNative（Native Method）
01-30 07：42：20.254：E / AndroidRuntime（267）：at java.lang.reflect.Method.invoke（Method.java:521）
01-30 07：42：20.254：E / AndroidRuntime（267）：at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:868）
01-30 07：42：20.254：E / AndroidRuntime（267）：at com.android.internal.os.ZygoteInit.main（ZygoteInit.java:626）
01-30 07：42：20.254：E / AndroidRuntime（267）：at dalvik.system.NativeStart.main（Native Method）
01-30 07：42：20.254：E / AndroidRuntime（267）：引起：java.lang.NullPointerException
01-30 07：42：20.254：E / AndroidRuntime（267）：at com.exercise.AndroidVideoCapture.AndroidVideoCapture.prepareMediaRecorder（AndroidVideoCapture.java:115）
01-30 07：42：20.254：E / AndroidRuntime（267）：at com.exercise.AndroidVideoCapture.AndroidVideoCapture.onStart（AndroidVideoCapture.java:62）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.Instrumentation.callActivityOnStart（Instrumentation.java:1129）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.Activity.performStart（Activity.java:3781）
01-30 07：42：20.254：E / AndroidRuntime（267）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2636）
01-30 07：42：20.254：E / AndroidRuntime（267）：... 11更多
01-30 07：42：23.314：I / Process（267）：发送信号。 PID：267 SIG：9
答案 0 :(得分：0)
尝试将代码放入OnCreate中开始录制
告诉我它是否有效
答案 1 :(得分：0)
在onStart()方法中，为什么使用NOT运算符？
使用prepareMediaRecorder()代替!prepareMediaRecorder()。
您想要检查prepareMediaRecorder()是否返回TRUE（表示您已准备好录制），而不是“不正确”......
尝试删除“！”
希望这会有所帮助!!