尝试检测震动时，我的应用程序中出现 NullPointerException。
在我的应用程序中，我有一个在后台运行的服务，以及一个调用方法 cameraIntent() 的活动。
public class Run1 extends Activity implements Shaker.Callback {
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
public static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
public static final int CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE = 200;
private Uri fileUri;
private static final String TAG = Shaker.class.getSimpleName();
final Handler handle = new Handler();
Shaker shaker;
shakeCameraService shakecamera;
public void miThread() {
Thread t = new Thread() {
public void run() {
handle.post(proceso);
}
};
t.start();
}
public final Runnable proceso = new Runnable() {
public void run() {
cameraIntent();
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.e("ONCREATE RUN1 ", "ONCREATE RUN1");
startService(new Intent(this, shakeCameraService.class));
}
public void cameraIntent() {
shaker = new Shaker(this, 5.0d, 500, this);
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to
// // save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file
// name
// start the image capture Intent
startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
if (fileUri != null) {
Log.e(TAG, "Result ok");
Log.e(TAG, "Image saved to:\n" + fileUri);
Log.e(TAG, "Image path:\n" + fileUri.getPath());
// uri.getLastPathSegment()
// if store
// in folder
}
} else if (resultCode == RESULT_CANCELED) {
Log.e(TAG, "RESULT CANCELED");
} else {
// Image capture failed, advise user
}
}
}
private static Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type) {
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(
Environment.getExternalStorageDirectory() + "/DCIM/Camera");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("ShakerCam", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFile;
}
public void shakingStarted() {
miThread();
}
public void shakingStopped() {
// TODO Auto-generated method stub
}
}
这是我的服务
public class shakeCameraService extends Service implements Shaker.Callback {
Run1 run1;
Shaker shaker =null;
@Override
public void onCreate() {
super.onCreate();
shaker = new Shaker(this, 5.0d, 500, this);
Log.e("ONCREATE SERVICE", "ONCREATE SERVICE");
}
@Override
public void onStart(Intent intent, int startId) {
shaker = new Shaker(this, 5.0d, 500, this);
Log.e("onStart Servicio ", "onStart Servicio ");
}
@Override
public void shakingStarted() {
shaker = new Shaker(this, 5.0d, 500, this);
Log.e("shakingstrated SERVICE", "shakingstrated SERVICE");
run1.cameraIntent();
}
@Override
public void shakingStopped() {
// TODO Auto-generated method stub
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
}
当时的错误是logcat me！和鼻子一样真的解决了这个问题！
04-19 23:26:30.788: ERROR/ONCREATE RUN1(356): ONCREATE RUN1
04-19 23:26:30.808: DEBUG/onCReate RUN1(356): antes de llamar a shakingstrated
04-19 23:26:30.808: DEBUG/AndroidRuntime(356): Shutting down VM
04-19 23:26:30.808: WARN/dalvikvm(356): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
04-19 23:26:30.822: ERROR/AndroidRuntime(356): Uncaught handler: thread main exiting due to uncaught exception
04-19 23:26:30.842: ERROR/AndroidRuntime(356): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sebastian.shakeCam/com.sebastian.shakeCam.Run1}: java.lang.NullPointerException
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.os.Handler.dispatchMessage(Handler.java:99)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.os.Looper.loop(Looper.java:123)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread.main(ActivityThread.java:4363)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at java.lang.reflect.Method.invokeNative(Native Method)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at java.lang.reflect.Method.invoke(Method.java:521)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at dalvik.system.NativeStart.main(Native Method)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): Caused by: java.lang.NullPointerException
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at com.sebastian.shakeCam.Run1.onCreate(Run1.java:57)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
04-19 23:26:30.842: ERROR/AndroidRuntime(356): ... 11 more