MenuItemCompat.getActionView 始终返回 null

我刚刚实施了v7 AppCompat支持库但是MenuItemCompat.getActionView在我测试的每个 Android 版本中总是返回 null（4.2.2、2.3.4 ....）

The SearchView显示在操作栏中，但它不响应触摸操作，也不会展开以显示其EditText就像一个简单的图标。

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);

    MenuItem searchItem = menu.findItem(R.id.action_search);
    SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
    if (searchView != null) {
        SearchViewCompat.setOnQueryTextListener(searchView, mOnQueryTextListener);
        searchView.setIconifiedByDefault(false);
        Log.d(TAG,"SearchView not null");
    } else
        Log.d(TAG, "SearchView is null");
    }
    return super.onCreateOptionsMenu(menu);
}

Menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto">

    <item android:id="@+id/action_search"
          app:showAsAction="always|collapseActionView"
          android:icon="@drawable/abc_ic_search"
          android:title="@string/action_bar_search"
          android:actionViewClass="android.support.v7.widget.SearchView"/>

    <item android:id="@+id/action_refresh"
          android:icon="@drawable/refresh"
          android:title="@string/action_bar_refresh"
          app:showAsAction="ifRoom"/>
</menu>

最后我找到了解决方案。

1. 更改命名空间actionViewClass from android:actionViewClass to app:actionViewClass

2. 实施android.support.v7.widget.SearchView.OnQueryTextListener当前活动的界面。

3. 直接使用setOnQueryTextListener代替SearchViewCompat.setOnQueryTextListener

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
     MenuInflater inflater = getMenuInflater();
     inflater.inflate(R.menu.menu, menu);
   
     MenuItem searchItem = menu.findItem(R.id.action_search);
     SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
     if (searchView != null) {
        searchView.setOnQueryTextListener(this);
     }
   
     return super.onCreateOptionsMenu(menu);
   }