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ViewStub的使用

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ViewStub经常用在ListView中,用来隐藏一些操作,使用起来也很简单,主要就是在ListView的Item中通过一个ViewStub来引用被隐藏的布局文件。监听用户点击Item,判断下当前是可见还是不可见,实时进行状态的转换即可。

效果图如下:

 

 

 

下面看代码:

MainActivity.java: 设置数据源

 

public class MainActivity extends Activity {

	private ListView lvList;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		lvList = (ListView)findViewById(R.id.lv_list);
		List<Map<String, String>> data = new ArrayList<Map<String, String>>();
		Map<String, String> map;
		for(int i = 0; i < 20; i++){
			
			map = new HashMap<String, String>();
			map.put("1234", "1234");
			data.add(map);
		}
		
		MainAdapter mainAdapter = new MainAdapter(this, data);
		lvList.setAdapter(mainAdapter);
	}

}
 

MainAdapter.java:

自定义Adapter,在getView中实现我们的效果:

 

public class MainAdapter extends BaseAdapter {

//	private Context context;
	private List<Map<String, String>> data;
	private LayoutInflater layoutInflater;

	public MainAdapter(Context context, List<Map<String, String>> data) {

//		this.context = context;
		this.data = data;
		layoutInflater = (LayoutInflater) context
				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
		
	}

	class ViewHolder {
		RelativeLayout rlListItem;// 点击展开或收起ViewStub

		View vsOperations;// 点击后显示的更多的操作
		ImageButton ibCompelete;// 打钩按钮
		ImageButton ibImportant;// 感叹号按钮
		ImageButton ibNotify;// 提醒按钮
		ImageButton ibLove;// 爱心按钮
		ImageButton ibShare;// 分享按钮
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		final ViewHolder viewHolder;
		if (convertView == null) {

			convertView = layoutInflater.inflate(R.layout.list_item_main_task,
					null);
			viewHolder = new ViewHolder();
			viewHolder.rlListItem = (RelativeLayout) convertView
					.findViewById(R.id.rl_list_item);
			viewHolder.vsOperations = (ViewStub) convertView
					.findViewById(R.id.vs_detail_operations);

			convertView.setTag(viewHolder);
		} else {

			viewHolder = (ViewHolder) convertView.getTag();
			viewHolder.vsOperations.setVisibility(View.GONE);
		}

		viewHolder.rlListItem.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if (viewHolder.vsOperations.getVisibility() == View.GONE) {
					
					if(viewHolder.vsOperations instanceof ViewStub){
						//关键!
						viewHolder.vsOperations = ((ViewStub)viewHolder.vsOperations).inflate();
					}
					viewHolder.vsOperations.setVisibility(View.VISIBLE);
					
				} else {

					viewHolder.vsOperations.setVisibility(View.GONE);
				}
			}
		});

		Log.e("111", "getView");
		
		return convertView;
	}

	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return data.size();
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return data.get(position);
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return position;
	}

}

 

activity_main.xml:主界面布局就一个ListView

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

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

</RelativeLayout>

 

list_item_main_task.xml: ListView中的每个Item,注意里面的ViewStub,通过它来引用一个布局文件,即隐藏的操作按钮。

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

    <!-- 每个ListItem除了ViewStub,都在这个标签里面 -->

    <RelativeLayout
        android:id="@+id/rl_list_item"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/bg_list_item_task"
        android:gravity="center" >

        <!-- android:descendantFocusability="blocksDescendants" 当ListView setOnItemClickListener点击没有效果的时候,加上这个 -->


        <!-- 任务的名称和超期时间 -->

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:gravity="center_vertical"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/tv_task_name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="任务1"
                android:textColor="#404040"
                android:textSize="22dp" />

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center_vertical"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/tv_over_date"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="超期2天"
                    android:textColor="#ff0000"
                    android:textSize="15dp" />

                <TextView
                    android:id="@+id/tv_name"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dip"
                    android:text="张小三"
                    android:textColor="#333333"
                    android:textSize="15dp" />
            </LinearLayout>
        </LinearLayout>
    </RelativeLayout>

    <ViewStub
        android:id="@+id/vs_detail_operations"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout="@layout/view_stub_tool_bar" />

</LinearLayout>
 

view_stub_tool_bar.xml: 被隐藏的操作按钮

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:gravity="center_vertical"
    android:paddingTop="8dip"
    android:background="@drawable/bg_list_item_task_view_stub" >

    <ImageButton
        android:id="@+id/btn_compelete"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:minHeight="55dp"
        android:background="@null"
        android:src="@drawable/ico_complete_selector" />

    <ImageButton
        android:id="@+id/btn_important"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:minHeight="55dp"
        android:background="@null"
        android:src="@drawable/ico_important_selector" />

    <ImageButton
        android:id="@+id/btn_"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:minHeight="55dp"
        android:background="@null"
        android:src="@drawable/ico_notify_selector" />

    <ImageButton
        android:id="@+id/btn_"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:minHeight="55dp"
        android:background="@null"
        android:src="@drawable/ico_love_selector" />

    <ImageButton
        android:id="@+id/btn_"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:minHeight="55dp"
        android:background="@null"
        android:src="@drawable/ico_share_selector" />

</LinearLayout>

 

一些资源文件这里就不贴出来了,有兴趣的同学可以下载demo来看看。

使用ViewStub的好处是,它并没有实例化这个View对象,而是在用户点击的时候才进行实例化,这样可以提高效率。特别是当你的listItem比较复杂的时候,效果很明显。

 

项目地址:https://github.com/michaelye/ViewStubDemo.git

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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