android - 迁移 android X androidx.appcompat.widget.SearchView 后获取 null

Question

我在xml中添加了android X

 public boolean onCreateOptionsMenu(final Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.notebook_menu, menu);
    MenuItem searchMenuItem = menu.findItem(R.id.notebook_search);      
    SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
    searchView = (SearchView) searchMenuItem.getActionView();
    searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
    searchView.setIconifiedByDefault(false);    
    }

从菜单

  <menu xmlns:android="http://schemas.android.com/apk/res/android" >
        <item
        android:id="@+id/notebook_search"
        app:actionViewClass="androidx.appcompat.widget.SearchView"
        android:icon="@drawable/tab_notebook_search"
        app:showAsAction="always|collapseActionView"
        android:title="@string/search"/>
        </menu>

错误

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.SearchView.setSearchableInfo(android.app.SearchableInfo)' on a null object reference

Answer 1

在菜单布局中使用 app:actionViewClass 而不是 android:actionViewClass。那就是问题所在。更改如下:

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/notebook_search"
        app:actionViewClass="androidx.appcompat.widget.SearchView"
        android:icon="@drawable/tab_notebook_search"
        app:showAsAction="always|collapseActionView"
        android:title="@string/search"/>
</menu>

除此之外，您的重构可能没有正确完成。请尝试Refactor > Migrate to AndroidX 然后按DoRefactor