JavaAndroid装置上的模拟器不在IndexOutOfBoundsException错误

这是我现在正在使用我的Android应用程序处理的问题.程序在模拟器上运行良好,没有任何错误,但在运行相同操作系统的真实设备上却出现了错误.

>我有一个应用程序小部件更新服务,用于更新我的小部件.此服务检查窗口小部件是否在屏幕上,否则不进行更新过程.在模拟器上工作正常.
>每次必须在OnReceive方法中更新窗口小部件时,我都会在字符串变量check_intent中捕获该意图,该变量告诉我其ENABLED,DELETED或UPDATE意图.
>我有一个SQLite表tuuserid_widget_enabled,其中仅启用了一个字段.启用意图后,将其切换为1,将其删除时将其切换为0.工作正常.
>当意图为UPDATE时,我检查DB表中的enable字段是否为1(如果为true),然后继续进行更新.这是我在设备上收到“游标索引超出范围”错误的地方,但是一切都在模拟器上按预期工作.

我将不胜感激.提前致谢.抱歉,如果我做错了什么,我正在学习Android.

这是错误-

02-02 18:58:03.007: ERROR/AndroidRuntime(4292): FATAL EXCEPTION: main
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): java.lang.RuntimeException: Unable to start service Test.TU.TUWidget$UpdateService@45d2b7d0 with Intent { cmp=Test.TU/.TUWidget$UpdateService }: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3282)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.ActivityThread.access$3600(ActivityThread.java:135)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2211)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.os.Handler.dispatchMessage(Handler.java:99)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.os.Looper.loop(Looper.java:144)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.ActivityThread.main(ActivityThread.java:4937)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at java.lang.reflect.Method.invokeNative(Native Method)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at java.lang.reflect.Method.invoke(Method.java:521)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at dalvik.system.NativeStart.main(Native Method)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.database.AbstractWindowedCursor.getInt(AbstractWindowedCursor.java:84)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at Test.TU.TUWidget$UpdateService.onStart(TUWidget.java:209)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.Service.onStartCommand(Service.java:420)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3267)
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): ... 10 more


以下是代码片段.

@Override
public void onReceive(Context context, Intent intent) {
check_intent = intent.getAction();
widgetUpdate.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
AlarmManager alarms = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
PendingIntent newPending = PendingIntent.getBroadcast(context, 0, widgetUpdate,PendingIntent.FLAG_UPDATE_CURRENT);
alarms.set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime()+ PERIOD, newPending);
context.startService(new Intent(context, UpdateService.class));
}
public static class UpdateService extends Service {
@Override
public void onStart(Intent intent, int startId) {
if (check_intent.contains("APPWIDGET_ENABLED")){
TUDB tdb = new TUDB(getApplicationContext());
final SQLiteDatabase db = tdb.getReadableDatabase();
String update_sql = "update tuuserid_widget_enabled set enabled = '1';";
if(db.isOpen() && !db.isReadOnly()){db.execSQL(update_sql);db.close();
}
}
else
**if (check_intent.contains("APPWIDGET_UPDATE")){
TUDB tdb1 = new TUDB(getBaseContext());
final SQLiteDatabase db1 = tdb1.getReadableDatabase();
String check_widget_enabled = "select enabled from tuuserid_widget_enabled;";
if(db1.isOpen() && !db1.isReadOnly()){Cursor cur = db1.rawQuery(check_widget_enabled, null); cur.moveToFirst();widget_enabled = cur.getInt(0); //this is where it bombscur.close();db1.close();
}**
if (widget_enabled == 1){RemoteViews updateViews = buildUpdate(getApplicationContext()); ComponentName thisWidget = new ComponentName(getApplicationContext(), TUWidget.class);AppWidgetManager manager = AppWidgetManager.getInstance(getApplicationContext());manager.updateAppWidget(thisWidget, updateViews);
}
}
else
if (check_intent.contains("APPWIDGET_DELETED")){
TUDB tdb = new TUDB(getBaseContext());
final SQLiteDatabase db = tdb.getReadableDatabase();
String update_sql = "update tuuserid_widget_enabled set enabled = '0';";
if(db.isOpen() && !db.isReadOnly()){db.execSQL(update_sql);db.close();
}
}
}


解决方法:

您的游标/数据库可能为空-没有行.尝试：

if (cur.moveToFirst()) { // returns false if cursor is empty
widget_enabled = cur.getInt(0);
} else {
widget_enabled = 0;
}