Question

我有一个listfragment类：

public class activityfeedScreen extends ListFragment implements OnItemClickListener {

private ListView activityfeed_feedList_listView;
private ActivityFeedBaseAdapter adapter;

public static final activityfeedScreen newInstance()
{
    activityfeedScreen fragment = new activityfeedScreen();
    Bundle bdl = new Bundle(1);
    fragment.setArguments(bdl);
    return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.activity_activityfeed_screen, container, false);

    activityfeed_feedList_listView = (ListView)v.findViewById(R.id.activityfeed_feedList_listView);
    activityfeed_feedList_listView.setAdapter(adapter);
    activityfeed_feedList_listView.setOnItemClickListener(this);

    return v;
}
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}
public void onItemClick(AdapterView<?> activityfeedlistview, View view, int position, long itemID) {
    Intent intent_activityfeed_showitemdescription = new Intent(view.getContext(), activityfeedItemScreen.class);
    startActivity(intent_activityfeed_showitemdescription);
}
}

在这堂课中，我收到错误：

    activityfeed_feedList_listView = (ListView)v.findViewById(R.id.activityfeed_feedList_listView);

我最初认为这是一个问题，因为getView（）为null所以我将它从onCreate方法移动到onCreateView（）方法。但我收到标题中所述的运行时错误。这是我的布局文件：

<?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:background="#E5E5E5"
android:layout_height="match_parent">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="10dp"
    android:layout_marginRight="10dp"
    android:layout_marginLeft="10dp">

    <ImageView
        android:id="@+id/activityfeed_profilePicture_imageView"
        android:layout_width="75dp"
        android:layout_height="75dp"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:src="@drawable/default_profile"/>

</RelativeLayout>
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#B9B9B9"
    android:layout_marginTop="20dp">

    <ListView
        android:id="@+id/activityfeed_feedList_listView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        </ListView>
    </RelativeLayout>

我知道我必须将listview id更改为

android:id="@android:id/list"

但我不确定如何在我的onCreateView方法中调用它。

感谢您的帮助！

Answer 1

是。首先，您必须更改ListView的ID，如下所示：

<ListView
    android:id="@android:id/list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
</ListView>

在onCreateView中，您可以android.R.id.list引用ID。这是因为Android内置资源位于android.R。你也可以在那里找到抽奖，风格等等（你可以用类似的maneer来称呼它们）。

考虑到上述情况，您的onCreateView方法应如下所示：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.activity_activityfeed_screen, container, false);

    activityfeed_feedList_listView = (ListView)v.findViewById(android.R.id.list);
    activityfeed_feedList_listView.setAdapter(adapter);
    activityfeed_feedList_listView.setOnItemClickListener(this);

    return v;
}

全部;）

ListFragment：运行时错误“您的内容必须有一个ListView，其id属性为'android.R.list'

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