java.lang.IndexOutOfBoundsException : Invalid index 2, 大小为 2 而在 Android 中删除 ListView 末尾的页脚 View ？

Question

我正在使用 ListView 实现分页。我试图在加载我的一些数据时添加页脚 View ，并在到达 ListView 末尾的 setOnScrollListener 的最后一页时删除 ListView 末尾的页脚 View 。但是在最后一页出现崩溃时出现 IndexOutOfBoundsException 问题:无效索引 2 , 大小为 2

我在初始化列表后添加页脚 View

ListView listView;

int pageCount = 0;
View footer;@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    listView = (ListView) findViewById(R.id.load);

    // Add footer view
    footer = ((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.prohressbar, null, false);
    listView.addFooterView(footer);

    List<All_Post> allDesc = dbhelper.getAllDescriptions(OFFSET);
    for (All_Post all_Post : allDesc){
        descArray.add(all_Post);
    }

    if (adapter == null) {
        adapter = new AllPostAdapter(this, R.layout.allpostlist, descArray);
        listView.setAdapter(adapter);
    }
    if (adapter != null) {
        adapter.notifyDataSetChanged();

        adapter = new AllPostAdapter(this, R.layout.allpostlist, descArray);
        listView.setAdapter(adapter);
        listView.invalidateViews();

        final SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        int item_position = sharedPreferences.getInt("item_position", 0);
        listView.setSelection(item_position);
    }

    Pegination();    

这是我的分页方法

public void Pegination() {

        final int activityCount  = sharedPreferences.getInt("ActivityListCount", 0);
        Log.e("", "activityCount in Pegination method =" + activityCount);

        listView.addFooterView(footer);

        final Button btnLoadMore = new Button(this);
        btnLoadMore.setText("Load More ....");

        listView.setOnScrollListener(new AbsListView.OnScrollListener() {
            private int total;

            @Override
            public void onScrollStateChanged(AbsListView absListView, int scrollState) {
            }

            @Override
            public void onScroll(AbsListView absListView, int firstItem, int visibleItemCount, final int totalItems) {

                total = firstItem + visibleItemCount;
                Log.e("", "total =" + total);

                if (totalItems > 0 && total > 0 && total == totalItems) {
                    if (preLast != total) {
                        if (pageCount < LocalPages) {
                            Handler handler = new Handler();
                            handler.postDelayed(new Runnable() {
                                public void run() {
                                    pageCount++;

                                    List<All_Post> allDesc = dbhelper.getAllDescriptions(OFFSET_SCROLL);
                                for (All_Post all_Post : allDesc) {

                                    descArray.add(all_Post);
                                }
                                if (adapter != null) {
                                    adapter.notifyDataSetChanged();
                                    listView.setAdapter(adapter);
                                    listView.setSelection(totalItems);
                                }
                                }
                            }, 2500);
                        }
                        preLast = total;
                        Log.e("", "11111111111 preLast=" + preLast);
                    }

                    preLast = total;
                    Log.e("", "222222222222222 preLast=" + preLast);
                    if (pageCount == LocalPages)
                    {
                        if (preLast == total)
                        {
                            if (activityCount == 200)
                            {
                                Log.e(" 11111 In btnLoadMore ", " ActivityListCount =" + activityCount);
                                Log.e("", "Go to else conditions --- 1 !!!!!!  pageCount=" + pageCount + " LocalPages=" + LocalPages);
                                pageCount = 0;

                                listView.removeFooterView(footer);
                                listView.addFooterView(btnLoadMore);
                            }
                        }
                            if (activityCount < 200) {
                                Log.e(" 222222 In btnLoadMore ", " ActivityListCount =" + activityCount);
                                Log.e("", "Go to else conditions --- 2 !!!!!!  pageCount=" + pageCount + " LocalPages=" + LocalPages);
                                pageCount = 0;
                                listView.removeFooterView(btnLoadMore);


                            }
                        }


                    }
                }
            }

        });

    }

这是我的 Log Cat 错误信息。

04-25 15:48:18.780  28787-28787/com.example.tazeen.classnkk E/﹕ total =137
04-25 15:48:18.780  28787-28787/com.example.tazeen.classnkk E/﹕ 222222222222222 preLast=137
04-25 15:48:18.781  28787-28787/com.example.tazeen.classnkk E/11111 In btnLoadMore﹕ ActivityListCount =200
04-25 15:48:18.781  28787-28787/com.example.tazeen.classnkk E/﹕ Go to else conditions --- 1 !!!!!!  pageCount=3 LocalPages=3
04-25 15:48:18.785  28787-28787/com.example.tazeen.classnkk D/AndroidRuntime﹕ Shutting down VM
04-25 15:48:18.788  28787-28787/com.example.tazeen.classnkk E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.tazeen.classnkk, PID: 28787
    java.lang.IndexOutOfBoundsException: Invalid index 2, size is 2
            at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
            at java.util.ArrayList.get(ArrayList.java:308)
            at android.widget.HeaderViewListAdapter.isEnabled(HeaderViewListAdapter.java:164)
            at android.widget.ListView.dispatchDraw(ListView.java:3334)
            at android.view.View.draw(View.java:15364)
            at android.widget.AbsListView.draw(AbsListView.java:4434)
            at android.view.View.updateDisplayListIfDirty(View.java:14242)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at android.view.View.draw(View.java:15364)
            at android.view.View.updateDisplayListIfDirty(View.java:14242)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at android.view.View.updateDisplayListIfDirty(View.java:14234)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at android.view.View.updateDisplayListIfDirty(View.java:14234)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at android.view.View.updateDisplayListIfDirty(View.java:14234)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at android.view.View.updateDisplayListIfDirty(View.java:14234)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.View.draw(View.java:15057)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3528)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3322)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchDraw(PhoneWindow.java:2845)
            at android.view.View.draw(View.java:15364)
            at android.widget.FrameLayout.draw(FrameLayout.java:647)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2824)
            at android.view.View.updateDisplayListIfDirty(View.java:14242)
            at android.view.View.getDisplayList(View.java:14272)
            at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:267)
            at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:273)
            at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:312)
            at android.view.ViewRootImpl.draw(ViewRootImpl.java:2852)
            at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2689)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2313)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1251)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6438)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:795)
            at android.view.Choreographer.doCallbacks(Choreographer.java:598)
            at android.view.Choreographer.doFrame(Choreographer.java:567)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:781)
            at android.os.Handler.handleCallback(Handler.java:810)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:189)
            at android.app.ActivityThread.main(ActivityThread.java:5529)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:950)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)

谁能帮我解决这个问题。为什么会出现 InvallidIndexOutOfBoundException 。

Answer 1

索引值从零开始。所以数组/列表的第一个元素是 0 e 第二个是 1。你说你的数据只有 2 个元素，所以索引 2 是你没有的 3 元素。查看您的代码并正确处理限制。

在这一行，intead == use <:

if (totalItems > 0 && total > 0 && total < totalItems) {

但也要验证您的整个代码以发现其他可能的错误。