你好,我正在學習android和試圖顯示自定義的ListView,但它無法加載。這個問題來自我的查詢,因爲列表是空的。請按照下面的解析示例,我做錯了什麼?無法檢索使用解析查詢
下面是我的代碼使用片段來顯示視圖,因爲它未能充氣。
EventTab.java:
//query Events for current user
private void queryEventListFromParse(){
//Create query for objects of type "Event"
ParseQuery<ParseObject> query = ParseQuery.getQuery("Event");
// Restrict to cases where the author is the current user.
//pass in a ParseUser and not String of that user
query.whereEqualTo("author", ParseUser.getCurrentUser());
query.orderByAscending("createAt");
// Run the query
query.findInBackground(new FindCallback<ParseObject>() {
@Override
public void done(List<ParseObject> eventList, ParseException e) {
if (e == null) {
// If there are results, update the list of event and notify the adapter
Log.d(TAG, "Im in background"); //im able to display image
eventList.clear();
for (ParseObject event : eventList) {
eventList.add(event);
}
updateEventsList();
} else {
Log.d(TAG, "Event retrieval error: " + e.getMessage());
}
}
});
}
重要更新: 感謝陰影的Droid您指出的錯誤。之所以getView()失敗,是因爲名爲evenList的List返回0,無法調用getView,因此返回0,並且無法顯示列表。
下面是錯誤消息,當我評論eventList.clear();
錯誤從控制檯:
12-05 04:52:10.511 11450-11450/com.example.davchen.skibuddies E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.davchen.skibuddies, PID: 11450
java.util.ConcurrentModificationException
at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573)
at com.example.davchen.skibuddies.Fragments.EventTab$1.done(EventTab.java:87)
at com.example.davchen.skibuddies.Fragments.EventTab$1.done(EventTab.java:80)
at com.parse.ParseTaskUtils$2$1.run(ParseTaskUtils.java:115)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5942)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
如果得到任何錯誤或崩潰檢查,然後分享它 –
後listview_event_item.xml和堆棧跟蹤 – johnrao07
@ρяσѕρєяK它無法顯示自定義列表。 – user3497437