我正在開發一個Android應用程序以便在Android developer guide的幫助下錄製視頻。我的程序中的所有代碼都與此頁面相同。Android視頻相機:NullPointerException
我在<application>
標記之外定義了權限。
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
當應用程序啓動時,相機預覽正在工作。但是當我按下RECEED按鈕時,給出了NullPointerException。例外:
E/VIDEO_RECORDER(4782): Camera creating error :Fail to connect to camera service
D/AndroidRuntime(4782): Shutting down VM
W/dalvikvm(4782): threadid=1: thread exiting with uncaught exception (group=0x4001e578)
E/AndroidRuntime(4782): FATAL EXCEPTION: main
java.lang.NullPointerException
at com.timico.video.CameraActivity.prepareVideoRecorder(CameraActivity.java:115)
at com.timico.video.CameraActivity.access$5(CameraActivity.java:110)
at com.timico.video.CameraActivity$1.onClick(CameraActivity.java:69)
at android.view.View.performClick(View.java:2538)
at android.view.View$PerformClick.run(View.java:9152)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3691)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
at dalvik.system.NativeStart.main(Native Method)
115 line is mCamera.unlock();
您能否讓我知道,這可能是什麼原因(在Samsung Galaxy S2和Nexus上測試)?謝謝
public static Camera getCameraInstance(){
Camera c = null;
try{
c = Camera.open();
} catch(Exception e){
Log.e(TAG, "Camera creating error :" + e.getMessage());
}
return c;
}
private boolean prepareVideoRecorder(){
mCamera = getCameraInstance();
mCamera.unlock();
mMediaRecorder = new MediaRecorder();
mMediaRecorder.setCamera(mCamera);
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mMediaRecorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());
mMediaRecorder.setPreviewDisplay(mPreview.getHolder().getSurface());
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
Log.d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
} catch (IOException e) {
Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
}
return true;
}
這是我的表面是如何創建的。
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
因此MCamera爲空,您用來獲取相機的代碼是什麼? – L7ColWinters 2012-01-27 15:35:15
謝謝。我已經添加了我的代碼。 – Chinthaka 2012-01-27 15:53:10
你有沒有從你的日誌中發現runtimeException? – L7ColWinters 2012-01-27 16:00:34