的onCreate之前不向活动的系统服务? [英] System services not available to Activities before onCreate?
问题描述
我无法弄清楚如何解决这个错误。我很绿色的Android和Java这样code会随着解释非常有帮助。有任何想法吗?感谢你。
在LogCat中:
致命异常:主要
ERROR / AndroidRuntime(13527):java.lang.RuntimeException的:无法启动的活动ComponentInfo {com.xxx.xxx/com.xxx.xxx.AC.List_AC}:java.lang.IllegalStateException:系统服务不提供给活动前的onCreate ()
ERROR / AndroidRuntime(13527):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
ERROR / AndroidRuntime(13527):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
ERROR / AndroidRuntime(13527):在android.app.ActivityThread.access $ 2300(ActivityThread.java:125)
ERROR / AndroidRuntime(13527):在android.app.ActivityThread $ H.handleMessage(ActivityThread.java:2033)
ERROR / AndroidRuntime(13527):在android.os.Handler.dispatchMessage(Handler.java:99)
ERROR / AndroidRuntime(13527):在android.os.Looper.loop(Looper.java:123)
ERROR / AndroidRuntime(13527):在android.app.ActivityThread.main(ActivityThread.java:4627)
ERROR / AndroidRuntime(13527):在java.lang.reflect.Method.invokeNative(本机方法)
ERROR / AndroidRuntime(13527):在java.lang.reflect.Method.invoke(Method.java:521)
ERROR / AndroidRuntime(13527):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:868)
ERROR / AndroidRuntime(13527):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
ERROR / AndroidRuntime(13527):在dalvik.system.NativeStart.main(本机方法)
ERROR / AndroidRuntime(13527):致:java.lang.IllegalStateException:之前的onCreate不向活动系统服务()
ERROR / AndroidRuntime(13527):在android.app.Activity.getSystemService(Activity.java:3526)
ERROR / AndroidRuntime(13527):在android.widget.ResourceCursorAdapter< INIT>(ResourceCursorAdapter.java:49)。
ERROR / AndroidRuntime(13527):在android.widget.SimpleCursorAdapter< INIT>(SimpleCursorAdapter.java:84)。
ERROR / AndroidRuntime(13527):在com.aeroTechnologies.flyDroid.AC.Adapter_AC< INIT>(Adapter_AC.java:21)。
ERROR / AndroidRuntime(13527):在com.xxx.xxx.AC.Set_AC_SortOrder.orderASC_Label(Set_AC_SortOrder.java:32)
ERROR / AndroidRuntime(13527):在com.xxx.xxx.AC.List_AC $ 1.运行(List_AC.java:49)
ERROR / AndroidRuntime(13527):在com.xxx.xxx.StorageStateChecker.performExternalStorageOperation(StorageStateChecker.java:10)
ERROR / AndroidRuntime(13527):在com.xxx.xxx.AC.List_AC.onCreate(List_AC.java:38)
ERROR / AndroidRuntime(13527):在android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
ERROR / AndroidRuntime(13527):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
ERROR / AndroidRuntime(13527):11 ...更多
在ListView的活动(List_AC.java):
公共类List_AC扩展ListActivity {
/ **
* - 第一次创建活动时调用
* ================================================= ==================
* /
@覆盖
公共无效的onCreate(包savedInstanceState){
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
的setContentView(R.layout.list_view2);
activityTitle =(TextView中)findViewById(R.id.titleBarTitle);
activityTitle.setText(顾问环行器);
searchList();
nextActivity();
可运行doIfMounted = ORDER_ASC;
StorageStateChecker.performExternalStorageOperation(doIfMounted);
}
/ **
* - 检查,看是否SD卡安装和放大器;加载默认列表顺序
* ================================================= =====================
** /
私有静态最后的Runnable ORDER_ASC =新的Runnable(){
公共无效的run(){
Set_AC_SortOrder.orderASC_Label();
}
};
本类检查是否Micro-SD卡安装(StorageStateChecker.java):
公共类StorageStateChecker {
公共静态布尔performExternalStorageOperation(Runnable的doIfMounted){
如果(android.os.Environment.getExternalStorageState()。等于(
android.os.Environment.MEDIA_MOUNTED)){
如果(doIfMounted!= NULL){
doIfMounted.run();
}
返回true;
}否则,如果(android.os.Environment.getExternalStorageState()。等于(
android.os.Environment.MEDIA_UNMOUNTED)){
//Alerts.sdCardMissing(this);
}
返回false;
}
}
本类调用的Runnable(Set_AC_SortOrder.java):
公共类Set_AC_SortOrder {
私有静态最后上下文list_AC =新List_AC();
布尔mExternalStorageAvailable = FALSE;
布尔mExternalStorageWriteable = FALSE;
静态字符串extStorageDirectory = Environment.getExternalStorageDirectory()
的ToString();
静态文件DBFILE =新的文件(extStorageDirectory
+/Aero-Technologies/flyDroid/dB/flyDroid.db);
静态SQLiteDatabase DB = SQLiteDatabase.openOrCreateDatabase(DBFILE,NULL);
/ **
* - 默认列表顺序(标签/民升序)
* ================================================= ====================
** /
公共静态无效orderASC_Label(){
光标databaseCursor = db.rawQuery(
SELECT * FROM AC_list ORDER BY`label` ASC,NULL);
Adapter_AC databaseListAdapter =新Adapter_AC(list_AC,
R.layout.list_item,databaseCursor,新的String [] {标签,
标题,说明,gotoURL},新的INT [] {
R.id.label,R.id.listTitle,R.id.caption,R.id.dummy});
databaseListAdapter.notifyDataSetChanged();
((ListActivity)list_AC).setListAdapter(databaseListAdapter);
}
}
我的适配器类(Adapter_AC.java):
公共类Adapter_AC扩展SimpleCursorAdapter {
静态游标dataCursor;
私人LayoutInflater mInflater;
公共Adapter_AC(上下文的背景下,INT布局,光标dataCursor,
的String []从,INT []键){
超(背景下,布局,dataCursor,从,到);
this.dataCursor = dataCursor;
mInflater = LayoutInflater.from(上下文);
}
公共查看getView(INT位置,查看convertView,ViewGroup中父){
ViewHolder持有人;
如果(convertView == NULL){
convertView = mInflater.inflate(R.layout.list_item,NULL);
持有人=新ViewHolder();
holder.text1 =(TextView中)convertView.findViewById(R.id.label);
holder.text2 =(TextView中)convertView.findViewById(R.id.listTitle);
holder.text3 =(TextView中)convertView.findViewById(R.id.caption);
holder.text4 =(TextView中)convertView.findViewById(R.id.dummy);
holder.text4.setVisibility(View.GONE);
convertView.setTag(保持器);
} 其他 {
支架=(ViewHolder)convertView.getTag();
}
dataCursor.moveToPosition(位置);
INT label_index = dataCursor.getColumnIndex(标签);
字符串标签= dataCursor.getString(label_index);
INT title_index = dataCursor.getColumnIndex(标题);
字符串标题= dataCursor.getString(title_index);
INT description_index = dataCursor.getColumnIndex(说明);
字符串描述= dataCursor.getString(description_index);
INT goto_index = dataCursor.getColumnIndex(gotoURL);
字符串gotoURL = dataCursor.getString(goto_index);
holder.text1.setText(标签);
holder.text1.setTag(标签);
holder.text2.setText(职称);
holder.text3.setText(介绍);
//holder.text4.setText(gotoURL);
holder.text4.setTag(gotoURL);
返回convertView;
}
静态类ViewHolder {
TextView的文本1;
TextView的文本2;
TextView的文本3;
TextView的文本4;
}
}
我敢打赌,你要创建一个的CursorAdapter
在构造函数
的活动的
。
上下文
不在活动构造可用的,它只是在 Activity.onCreate()
方法可用和超越。
和一个顶端尖...
创建的CursorAdapter
与空的 Activity.onCreate一个
和使用光标
() ListView.getAdapter()。changeCursor(newCursor)
指定 newCursor
一次背景线程返回一个人口稠密光标
。
I cant figure out how to fix this error. I am very green to Android and Java so code will be very helpful along with explanations. Any Ideas? Thank-you.
The LogCat:
FATAL EXCEPTION: main
ERROR/AndroidRuntime(13527): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xxx.xxx/com.xxx.xxx.AC.List_AC}: java.lang.IllegalStateException: System services not available to Activities before onCreate()
ERROR/AndroidRuntime(13527): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
ERROR/AndroidRuntime(13527): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
ERROR/AndroidRuntime(13527): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
ERROR/AndroidRuntime(13527): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
ERROR/AndroidRuntime(13527): at android.os.Handler.dispatchMessage(Handler.java:99)
ERROR/AndroidRuntime(13527): at android.os.Looper.loop(Looper.java:123)
ERROR/AndroidRuntime(13527): at android.app.ActivityThread.main(ActivityThread.java:4627)
ERROR/AndroidRuntime(13527): at java.lang.reflect.Method.invokeNative(Native Method)
ERROR/AndroidRuntime(13527): at java.lang.reflect.Method.invoke(Method.java:521)
ERROR/AndroidRuntime(13527): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
ERROR/AndroidRuntime(13527): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
ERROR/AndroidRuntime(13527): at dalvik.system.NativeStart.main(Native Method)
ERROR/AndroidRuntime(13527): Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate()
ERROR/AndroidRuntime(13527): at android.app.Activity.getSystemService(Activity.java:3526)
ERROR/AndroidRuntime(13527): at android.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:49)
ERROR/AndroidRuntime(13527): at android.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:84)
ERROR/AndroidRuntime(13527): at com.aeroTechnologies.flyDroid.AC.Adapter_AC.<init>(Adapter_AC.java:21)
ERROR/AndroidRuntime(13527): at com.xxx.xxx.AC.Set_AC_SortOrder.orderASC_Label(Set_AC_SortOrder.java:32)
ERROR/AndroidRuntime(13527): at com.xxx.xxx.AC.List_AC$1.run(List_AC.java:49)
ERROR/AndroidRuntime(13527): at com.xxx.xxx.StorageStateChecker.performExternalStorageOperation(StorageStateChecker.java:10)
ERROR/AndroidRuntime(13527): at com.xxx.xxx.AC.List_AC.onCreate(List_AC.java:38)
ERROR/AndroidRuntime(13527): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
ERROR/AndroidRuntime(13527): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
ERROR/AndroidRuntime(13527): ... 11 more
In the ListView Activity (List_AC.java):
public class List_AC extends ListActivity {
/**
* -- Called when the activity is first created
* ===================================================================
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.list_view2);
activityTitle = (TextView) findViewById(R.id.titleBarTitle);
activityTitle.setText("ADVISORY CIRCULATORS");
searchList();
nextActivity();
Runnable doIfMounted = ORDER_ASC;
StorageStateChecker.performExternalStorageOperation(doIfMounted );
}
/**
* -- Check to See if the SD Card is Mounted & Loads Default List Order
* ======================================================================
**/
private static final Runnable ORDER_ASC = new Runnable() {
public void run() {
Set_AC_SortOrder.orderASC_Label();
}
};
This class checks to see if the SD-Card is mounted (StorageStateChecker.java):
public class StorageStateChecker {
public static boolean performExternalStorageOperation(Runnable doIfMounted) {
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)) {
if (doIfMounted != null) {
doIfMounted.run();
}
return true;
} else if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_UNMOUNTED)) {
//Alerts.sdCardMissing(this);
}
return false;
}
}
The class for calling the Runnables (Set_AC_SortOrder.java):
public class Set_AC_SortOrder {
private static final Context list_AC = new List_AC();
boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
static String extStorageDirectory = Environment.getExternalStorageDirectory()
.toString();
static File dbfile = new File(extStorageDirectory
+ "/Aero-Technologies/flyDroid/dB/flyDroid.db");
static SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile, null);
/**
* -- Default List Order ( Label/Num Ascending)
* =====================================================================
**/
public static void orderASC_Label() {
Cursor databaseCursor = db.rawQuery(
"SELECT * FROM AC_list ORDER BY `label` ASC", null);
Adapter_AC databaseListAdapter = new Adapter_AC(list_AC,
R.layout.list_item, databaseCursor, new String[] { "label",
"title", "description", "gotoURL" }, new int[] {
R.id.label, R.id.listTitle, R.id.caption, R.id.dummy });
databaseListAdapter.notifyDataSetChanged();
((ListActivity) list_AC).setListAdapter(databaseListAdapter);
}
}
My Adapter Class (Adapter_AC.java):
public class Adapter_AC extends SimpleCursorAdapter {
static Cursor dataCursor;
private LayoutInflater mInflater;
public Adapter_AC(Context context, int layout, Cursor dataCursor,
String[] from, int[] to) {
super(context, layout, dataCursor, from, to);
this.dataCursor = dataCursor;
mInflater = LayoutInflater.from(context);
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.text1 = (TextView) convertView.findViewById(R.id.label);
holder.text2 = (TextView) convertView.findViewById(R.id.listTitle);
holder.text3 = (TextView) convertView.findViewById(R.id.caption);
holder.text4 = (TextView) convertView.findViewById(R.id.dummy);
holder.text4.setVisibility(View.GONE);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
dataCursor.moveToPosition(position);
int label_index = dataCursor.getColumnIndex("label");
String label = dataCursor.getString(label_index);
int title_index = dataCursor.getColumnIndex("title");
String title = dataCursor.getString(title_index);
int description_index = dataCursor.getColumnIndex("description");
String description = dataCursor.getString(description_index);
int goto_index = dataCursor.getColumnIndex("gotoURL");
String gotoURL = dataCursor.getString(goto_index);
holder.text1.setText(label);
holder.text1.setTag(label);
holder.text2.setText(title);
holder.text3.setText(description);
//holder.text4.setText(gotoURL);
holder.text4.setTag(gotoURL);
return convertView;
}
static class ViewHolder {
TextView text1;
TextView text2;
TextView text3;
TextView text4;
}
}
I would bet that you are trying to create a CursorAdapter
in the Constructor
of your Activity
.
Context
is not available in the Activities Constructor, it is only available in the Activity.onCreate()
method and beyond.
And for a top tip...
Create the CursorAdapter
with a Cursor
of null in Activity.onCreate()
and use ListView.getAdapter().changeCursor(newCursor)
to assign newCursor
once a background thread has returned a populated Cursor
.
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