可能重复:
Android RuntimeException: 无法实例化服务
我整天都在尝试解决以下问题，但似乎没有任何效果.
I have been trying to fix the following problem all day but nothing seems to work.
我有一个小部件，它通过 IntentService 更新它的视图.但是在尝试启动此服务时，我不断收到 InstantiationException.下面是错误的堆栈跟踪和我用来启动服务的代码.我不相信我需要发布服务的代码，因为它甚至从未启动，但如果有人不这么认为，我当然会这样做.
I have a widget which gets it's views updated via an IntentService. But i keep getting an InstantiationException when trying to start this service. Below is the stack trace of the error and the code i use to launch the service. I don't believe i need to post the code of the service as it is never even started, but if someone thinks otherwise i will of course do so.
堆栈跟踪
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): FATAL EXCEPTION: main
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): java.lang.RuntimeException: Unable to instantiate service syrligt.cashtrack.widgets.StatisticsWidgetUpdateService: java.lang.InstantiationException: syrligt.cashtrack.widgets.StatisticsWidgetUpdateService
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.app.ActivityThread.handleCreateService(ActivityThread.java:1904)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.app.ActivityThread.access$2500(ActivityThread.java:117)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:982)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.os.Handler.dispatchMessage(Handler.java:99)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.os.Looper.loop(Looper.java:123)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.app.ActivityThread.main(ActivityThread.java:3647)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at java.lang.reflect.Method.invokeNative(Native Method)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at java.lang.reflect.Method.invoke(Method.java:507)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at dalvik.system.NativeStart.main(Native Method)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): Caused by: java.lang.InstantiationException: syrligt.cashtrack.widgets.StatisticsWidgetUpdateService
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at java.lang.Class.newInstanceImpl(Native Method)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at java.lang.Class.newInstance(Class.java:1409)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): at android.app.ActivityThread.handleCreateService(ActivityThread.java:1901)
05-30 13:58:47.150: ERROR/AndroidRuntime(1163): ... 10 more
小部件代码
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
for(int i = 0; i<appWidgetIds.length ; i++){
Intent intent = new Intent(context,StatisticsWidgetUpdateService.class);
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
context.startService(intent);
}
}
服务代码
public class StatisticsWidgetUpdateService extends IntentService {
public StatisticsWidgetUpdateService(String name) {
super(name);
}
@Override
protected void onHandleIntent(Intent intent) {
AppWidgetManager appWidgetManager=AppWidgetManager.getInstance(this);
int appWidgetId = intent.getExtras().getInt(AppWidgetManager.EXTRA_APPWIDGET_ID);
CashDB cdb = new CashDB(this);
cdb.open();
RemoteViews updatedViews = new RemoteViews(getPackageName(), R.layout.statistics_widget);
updatedViews.removeAllViews(R.id.list);
PendingIntent pendingIntent = null;
Cursor c = null;
Intent i = null;
SharedPreferences sp = getSharedPreferences(Preferences.PREFERENCES, 0);
double incomeAmount = cdb.sumTransactions(null, new TimeFrame(sp.getInt(Preferences.DEFAULT_TIME_FRAME, TimeFrame.ALL_TIME)), 1);
double expenseAmount = Math.abs(cdb.sumTransactions(null, new TimeFrame(sp.getInt(Preferences.DEFAULT_TIME_FRAME, TimeFrame.ALL_TIME)), -1));
int value = StatisticsWidgetConfig.getConfig(this, appWidgetId);
c = cdb.fetchCategoriesWithSums(new TimeFrame(sp.getInt(Preferences.DEFAULT_TIME_FRAME, TimeFrame.ALL_TIME)), value, 3);
updatedViews.setTextViewText(R.id.balance, StringConversion.formatAmount(incomeAmount - expenseAmount));//balance text
updatedViews.setViewVisibility(R.id.value_bar, incomeAmount - expenseAmount < 0 ? R.drawable.list_item_value_red_medium : R.drawable.list_item_value_green_medium);//value bar
updatedViews.setTextViewText(R.id.income, StringConversion.formatAmount(incomeAmount));//income text
updatedViews.setTextViewText(R.id.expense, StringConversion.formatAmount(expenseAmount));//expense text
updatedViews.setTextViewText(R.id.popularity, Integer.toString(cdb.fetchAllTransactions(new TimeFrame(sp.getInt(Preferences.DEFAULT_TIME_FRAME, TimeFrame.ALL_TIME)), null, null,null).getCount()));//popularity text
for(int j = 0; j<c.getCount();j++){
c.moveToPosition(j);
RemoteViews statisticsView = new RemoteViews(getPackageName(), R.layout.statistics_widget_list);
statisticsView.setTextViewText(R.id.name, c.getString(c.getColumnIndexOrThrow(CashDB.CATEGORY_NAME)));//category name
statisticsView.setImageViewResource(R.id.icon, c.getInt(c.getColumnIndexOrThrow(CashDB.CATEGORY_IMAGE)));//category icon
statisticsView.setViewVisibility(R.id.starred, c.getInt(c.getColumnIndexOrThrow(CashDB.CATEGORY_STARRED)) == 1 ? View.VISIBLE : View.GONE);//starred icon
double procent = c.getLong(c.getColumnIndexOrThrow(CashDB.TRANSACTION_SUM));
procent = procent/(value == -1 ? expenseAmount : incomeAmount);
procent = Math.abs(procent * 100);
if((procent%1) < 0.1){
statisticsView.setTextViewText( R.id.procent, String.format("%.0f%s",procent," %"));//procentage
}else{
statisticsView.setTextViewText( R.id.procent, String.format("%.1f%s",procent," %"));//procentage
}
Bitmap bmp;
if(value == -1){
bmp=BitmapFactory.decodeResource(getResources(), R.drawable.progress_bar_red);
}else{
bmp=BitmapFactory.decodeResource(getResources(), R.drawable.progress_bar_green);
}
int width=(int) (procent*4.056); // kankse fuckar upp p andra display storlekar
if(width<2){
width=2;
}
width = (int) getResources().getDisplayMetrics().density * width;
int height=10;
Bitmap resizedbitmap=Bitmap.createScaledBitmap(bmp, width, height, true);
statisticsView.setImageViewBitmap(R.id.progress_bar, resizedbitmap);//procent bar
i = new Intent(this, ViewCategory.class);
i.putExtra(CashDB.CATEGORY_ID, c.getLong(c.getColumnIndexOrThrow(CashDB.CATEGORY_ID)));
i.setAction("cashtrackViewCategory"+c.getLong(c.getColumnIndexOrThrow(CashDB.CATEGORY_ID)));
pendingIntent = PendingIntent.getActivity(this, 0, i, PendingIntent.FLAG_UPDATE_CURRENT);
statisticsView.setOnClickPendingIntent(R.id.statistics_widget_list_layout, pendingIntent);
updatedViews.addView(R.id.list, statisticsView);
}
c.close();
cdb.close();
appWidgetManager.updateAppWidget(appWidgetId, updatedViews);
}
}
你的服务需要有一个公共的无参数构造函数.否则，Android 将无法实例化它.
You service needs to have a public no-args constructor. Otherwize, Android will not be able to instantiate it.
所以替换
public StatisticsWidgetUpdateService(String name) {
super(name);
}
与
public StatisticsWidgetUpdateService() {
super("SOME NAME");
}
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