使用AsyncTask進行Android ListView過濾

Question

我有兩個相互競爭的問題。

情況

在嘗試更改時，我嘗試通過EditText篩選出大量的Listview 10k +項目。

錯誤1

ANR keyDispatchingTimedOut錯誤

我在UI線程上進行了過濾操作（在當時看來是合理的），並且我認為這是導致某些手機出現錯誤的原因...

嘗試修復錯誤1

創建了一個AsyncTask專門用於調用我的過濾器功能...

    /// <summary>
    /// Implementation of Android AsyncTask to perform the StudentFiltering in background
    /// </summary>
    internal class FilterStudentsTask : AsyncTask
    {
        private Student[] _students;
        private StudentList _outer;
        private StudentListAdapter _adapter;
        private string _filterText;

        public FilterStudentsTask(StudentList outer, StudentListAdapter adapter, string filterText)
        {
            this._outer = outer;
            this._adapter = adapter;
            this._filterText = filterText;
        }

        protected override Java.Lang.Object DoInBackground(params Java.Lang.Object[] @params)
        {
            // filter the list
            this._adapter.filterStudents(this._filterText);
            return true;
        }

        protected override void OnPostExecute(Java.Lang.Object result)
        {
            // Notify adapter of Data Change (to trigger re-draw)
            this._adapter.NotifyDataSetChanged();
            base.OnPostExecute(result);
        }
    }

錯誤2

所以現在，因為我還有另一個線程負責過濾，所以這並不是說我不應該對這種類型的操作使用后台線程，而應該只在UI線程上發生。

E/AndroidRuntime( 9738): FATAL EXCEPTION: main
E/AndroidRuntime( 9738): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sur
e the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131361885, class mapdroid.ColorFade
ListView) with Adapter(class mapdroid.StudentList_StudentListAdapter)]
E/AndroidRuntime( 9738):        at android.widget.ListView.layoutChildren(ListView.java:1510)
E/AndroidRuntime( 9738):        at android.widget.AbsListView.onLayout(AbsListView.java:1260)
E/AndroidRuntime( 9738):        at android.view.View.layout(View.java:7175)
E/AndroidRuntime( 9738):        at android.widget.RelativeLayout.onLayout(RelativeLayout.java:912)
E/AndroidRuntime( 9738):        at android.view.View.layout(View.java:7175)
E/AndroidRuntime( 9738):        at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
E/AndroidRuntime( 9738):        at android.view.View.layout(View.java:7175)
E/AndroidRuntime( 9738):        at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
E/AndroidRuntime( 9738):        at android.view.View.layout(View.java:7175)
E/AndroidRuntime( 9738):        at android.view.ViewRoot.performTraversals(ViewRoot.java:1140)
E/AndroidRuntime( 9738):        at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
E/AndroidRuntime( 9738):        at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 9738):        at android.os.Looper.loop(Looper.java:130)
E/AndroidRuntime( 9738):        at android.app.ActivityThread.main(ActivityThread.java:3683)
E/AndroidRuntime( 9738):        at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 9738):        at java.lang.reflect.Method.invoke(Method.java:507)
E/AndroidRuntime( 9738):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
E/AndroidRuntime( 9738):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
E/AndroidRuntime( 9738):        at dalvik.system.NativeStart.main(Native Method)
W/ActivityManager(  111):   Force finishing activity MapDroid.MapDroid/mapdroid.StudentList
W/ActivityManager(  111): Activity pause timeout for HistoryRecord{40670aa0 MapDroid.MapDroid/mapdroid.StudentList}

我是否缺少某些內容，但是這些錯誤似乎存在沖突嗎？ 您如何調和他們？

Answer 1

我認為這個問題在這里

protected override Java.Lang.Object DoInBackground(params Java.Lang.Object[] @params)
    {
        // filter the list
        this._adapter.filterStudents(this._filterText);
        return true;
    }

您無法通過非UI線程訪問Apapter類。 嘗試做這樣的事情

protected override Java.Lang.Object DoInBackground(params Java.Lang.Object[] @params)
    {
        // filter the list
        result = students.filterStudents(this._filterText);
        return true;
    }


protected override void OnPostExecute(Java.Lang.Object result)
        {
            // Notify adapter of Data Change (to trigger re-draw)
            this._adapter.SetItems(result);
            this._adapter.NotifyDataSetChanged();
            base.OnPostExecute(result);
        }