Android 当 ListView 为空时显示空视图
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Showing empty view when ListView is empty
提问by Sheehan Alam
For some reason the empty view, a TextViewin this case, always appears even when the ListViewis not empty. I thought the ListViewwould automatically detect when to show the empty view.
出于某种原因，即使ListView不为空，空视图（在本例中为TextView）也会始终出现。我认为ListView会自动检测何时显示空视图。
<RelativeLayout android:id="@+id/LinearLayoutAR"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<ListView android:id="@+id/ARListView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></ListView>
<ProgressBar android:id="@+id/arProgressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"></ProgressBar>
<!-- Here is the view to show if the list is emtpy -->
<TextView android:id="@id/android:empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No Results" />
</RelativeLayout>
How can I hook up the empty view properly?
如何正确连接空视图？
采纳答案by Nathan Schwermann
It should be like this:
应该是这样的：
<TextView android:id="@android:id/empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No Results" />
Note the idattribute.
注意id属性。
回答by appsthatmatter
When you extend FragmentActivityor Activityand notListActivity, you'll want to take a look at:
当您扩展FragmentActivityorActivity和not 时ListActivity，您需要查看：
回答by Eddy
As appsthatmatter says, in the layout something like:
正如 appsthatmatter 所说，在布局中是这样的：
<ListView android:id="@+id/listView" ... />
<TextView android:id="@+id/emptyElement" ... />
and in the linked Activity:
并在链接的活动中：
this.listView = (ListView) findViewById(R.id.listView);
this.listView.setEmptyView(findViewById(R.id.emptyElement));
Does also work with a GridView...
也适用于 GridView...
回答by kgandroid
I tried all the above solutions.I came up solving the issue.Here I am posting the full solution.
我尝试了上述所有解决方案。我想出了解决问题的方法。我在这里发布完整的解决方案。
The xml file:
该XML文件：
<RelativeLayout
android:id="@+id/header_main_page_clist1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="20dp"
android:paddingBottom="10dp"
android:background="#ffffff" >
<ListView
android:id="@+id/lv_msglist"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="@color/divider_color"
android:dividerHeight="1dp" />
<TextView
android:id="@+id/emptyElement"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="NO MESSAGES AVAILABLE!"
android:textColor="#525252"
android:textSize="19.0sp"
android:visibility="gone" />
</RelativeLayout>
The textView ("@+id/emptyElement") is the placeholder for the empty listview.
textView( "@+id/emptyElement") 是空列表视图的占位符。
Here is the code for java page:
这是java页面的代码：
lvmessage=(ListView)findViewById(R.id.lv_msglist);
lvmessage.setAdapter(adapter);
lvmessage.setEmptyView(findViewById(R.id.emptyElement));
Remember to place the emptyView after binding the adapter to listview.Mine was not working for first time and after I moved the setEmptyView after the setAdapter it is now working.
记住在将适配器绑定到 listview 之后放置 emptyView。我的第一次没有工作，在我在 setAdapter 之后移动 setEmptyView 之后，它现在正在工作。
Output:
输出：
回答by LOG_TAG
I highly recommend you to use ViewStubs like this
我强烈建议你像这样使用 ViewStubs
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
<ViewStub
android:id="@android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout="@layout/empty" />
</FrameLayout>
See the full example from Cyril Mottier
请参阅Cyril Mottier的完整示例
回答by Yaojin
<ListView android:id="@+id/listView" ... />
<TextView android:id="@+id/empty" ... />
and in the linked Activity:
this.listView = (ListView) findViewById(R.id.listView);
this.listView.setEmptyView(findViewById(R.id.empty));
This works clearly with FragmentActivity if you are using the support library. Tested this by building for API 17 i.e. 4.2.2 image.
如果您使用支持库，这对 FragmentActivity 很有效。通过为 API 17 即 4.2.2 镜像构建来测试这一点。
回答by Mizipzor
Activity code, its important to extend ListActivity.
活动代码，扩展ListActivity.
package com.example.mylistactivity;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import com.example.mylistactivity.R;
// It's important to extend ListActivity rather than Activity
public class MyListActivity extends ListActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mylist);
// shows list view
String[] values = new String[] { "foo", "bar" };
// shows empty view
values = new String[] { };
setListAdapter(new ArrayAdapter<String>(
this,
android.R.layout.simple_list_item_1,
android.R.id.text1,
values));
}
}
Layout xml, the id in both views are important.
布局xml，两个视图中的id都很重要。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<!-- the android:id is important -->
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<!-- the android:id is important -->
<TextView
android:id="@android:id/empty"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="i am empty"/>
</LinearLayout>
回答by Luís Ramalho
Just to add that you don't really need to create new IDs, something like the following will work.
只是要补充一点，您实际上并不需要创建新的 ID，如下所示。
In the layout:
在布局中：
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@android:id/list"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@android:id/empty"
android:text="Empty"/>
Then in the activity:
然后在活动中：
ListView listView = (ListView) findViewById(android.R.id.list);
listView.setEmptyView(findViewById(android.R.id.empty));
回答by Matt
I had this problem. I had to make my class extend ListActivity rather than Activity, and rename my list in the XML to android:id="@android:id/list"
我有这个问题。我必须让我的类扩展 ListActivity 而不是 Activity，并将 XML 中的列表重命名为android:id="@android:id/list"
回答by Mika
A programmatically solution will be:
以编程方式解决方案将是：
TextView textView = new TextView(context);
textView.setId(android.R.id.empty);
textView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
textView.setText("No result found");
listView.setEmptyView(textView);
