ListView中的itemCount和Adapter中的get

错误信息

12-16 15:33:59.338 27587-27587/? E/InputEventReceiver: Exception dispatching input event.
12-16 15:33:59.338 27587-27587/? E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
12-16 15:33:59.359 27587-27587/? E/MessageQueue-JNI: java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. Make sure your adapter calls notifyDataSetChanged() when its content changes. [in ListView(2131165248, class com.whf.demo.TestListView) with Adapter(class com.whf.demo.ListAdapter)]
    at android.widget.ListView.layoutChildren(ListView.java:1620)
    at android.widget.AbsListView.onTouchUp(AbsListView.java:4217)
    at android.widget.AbsListView.onTouchEvent(AbsListView.java:3986)
    at android.view.View.dispatchTouchEvent(View.java:10038)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2347)
    at android.widget.AbsListView.dispatchTouchEvent(AbsListView.java:986)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2672)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2361)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2672)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2361)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2672)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2361)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2672)
... ...

错误来源

//ListView.java
@Override
protected void layoutChildren() {
    ... ...
    if (mItemCount == 0) {
        resetList();
        invokeOnItemScrollListener();
        return;
    } else if (mItemCount != mAdapter.getCount()) {
        throw new IllegalStateException("The content of the adapter has changed but "
        + "ListView did not receive a notification. Make sure the content of "
        + "your adapter is not modified from a background thread, but only from "
        + "the UI thread. Make sure your adapter calls notifyDataSetChanged() "
        + "when its content changes. [in ListView(" + getId() + ", " + getClass()
        + ") with Adapter(" + mAdapter.getClass() + ")]");
    }
    ... ...
}

错误分析

• 确保Adapter的数据更新后一定要调用notifyDataSetChanged()方法通知ListView
• 数据更新和notifyDataSetChanged()放在UI线程内，且必须同步顺序执行，不可异步
• 仔细检查确认getCount()方法返回值是否正确

容错处理

//重写ListView （如果上述方案还未解决则选择该容错机制，否则不推荐）
@Override
protected void layoutChildren() {
    try {
        super.layoutChildren();
    } catch (IllegalStateException e) {
        Log.e("TestDemo", "SlideItemListView item count not equal notificationAdapter.getCount()");
        ((ListAdapter)getAdapter()).notifyDataSetChanged();
    }
}