ListFragment给出了ListView,其id属性为’android.R.id.list’

2023年6月2日 176次阅读

我正在尝试实现一个简单的列表/详细信息视图,如图1
here,但我得到一个“你的内容必须有一个ListView,其id属性是’android.R.id.list’”运行时异常.如果结果的数量可以通过,似乎已经详细讨论了这个错误,但大多数答案似乎是关于扩展ListActivity,而我正在扩展ListFragment.到目前为止,我没有运气来修复它.基本活动是：

SpeciesListActivity.java

public class SpeciesListActivity extends MenuItemActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_species_list);

        // Check if the species_detail view is available. If it is
        // we're running both fragments together.
        if (findViewById(R.id.species_detail) != null) {
        }
    }
}

片段通过其布局文件包含在内：

activity_species_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:baselineAligned="false"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment android:name="com.example.fragments.SpeciesListFragment"
            android:id="@+id/species_list"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
    <fragment android:name="net.gamebreeder.fragments.SpeciesDetailFragment"
            android:id="@+id/species_detail"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
</LinearLayout>

这是两个窗格布局,除了第二个片段(id species_detail)之外,单个窗格是相同的.

有问题的片段：

SpeciesListFragment.java

public class SpeciesListFragment extends ListFragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_species_list, container, false);
    }
}

片段的布局：

fragment_species_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="8dp"
    android:paddingRight="8dp">

    <ListView android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:drawSelectorOnTop="false"/>

    <TextView android:id="@id/android:empty"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/empty_string"/>

</LinearLayout>

我已经尝试将SpeciesListFragment更改为不覆盖onCreateView()以强制它使用默认值,因为根据docs：

Note: If your fragment is a subclass of ListFragment, the default implementation returns a ListView from onCreateView(), so you don’t need to implement it.

但我仍然得到：
java.lang.RuntimeException：您的内容必须具有一个ListView,其id属性为’android.R.id.list’

我发现的一个问题建议我确保我在主要活动中扩展FragmentActivity,这正是MenuItemActivity的内容：

public class MenuItemActivity extends FragmentActivity {

它基本上只是一个包装器,所以我不必在每个活动中手动创建菜单.

任何帮助将不胜感激 – 我希望我只是错过了一些简单的东西.

编辑2013-06-27

我已经尝试将fragment_species_list.xml中的id格式化为@ id / android：list和@android：id / list,但都不起作用.文档说使用@id / android：list但我读过的其他问题似乎表明两者都应该有效,但我得到了两者的错误.我也试过@ id / list.

我还根据以下答案更改了以下内容：

activity_species_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:baselineAligned="false"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment class="com.example.fragments.SpeciesListFragment"
            android:id="@+id/species_list"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
    <fragment class="net.gamebreeder.fragments.SpeciesDetailFragment"
            android:id="@+id/species_detail"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
</LinearLayout>

最佳答案 将此包含添加到列表布局中：

<include layout="@android:layout/list_content" />
<ListView 
    android:id="@+id/list" 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white" />

这对我有用….

android站点上的文档：http://developer.android.com/reference/android/app/ListFragment.html

public View onCreateView (LayoutInflater inflater, ViewGroup
container, Bundle savedInstanceState)

Added in API level 11 Provide default implementation to return a
simple list view. Subclasses can override to replace with their own
layout. If doing so, the returned view hierarchy must have a ListView
whose id is android.R.id.list and can optionally have a sibling view
id android.R.id.empty that is to be shown when the list is empty.

If you are overriding this method with your own custom content,
consider including the standard layout list_content in your layout
file, so that you continue to retain all of the standard behavior of
ListFragment. In particular, this is currently the only way to have
the built-in indeterminant progress state be shown.

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