Android ListView item 选中高亮显示之高效实现方式

之前在一篇文章中提到过 Android ListView item 选中高亮显示 的实现方式，具体可以查看这篇博文，这里提供另外一种更为高效的方式。

先看效果

未选中时

选中某一项时

下面通过一段代码来讲解实现过程

activity_main.xml

<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/mListView"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:choiceMode="singleChoice"        android:dividerHeight="1dp"        android:divider="#d4d4d4"/></RelativeLayout>

list_selector.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:drawable="@drawable/list_item_bg_normal" android:state_activated="false"/>    <item android:drawable="@drawable/list_item_bg_pressed" android:state_pressed="true"/>    <item android:drawable="@drawable/list_item_bg_pressed" android:state_activated="true"/></selector>

list_item_bg_normal.xml

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" >        <gradient      android:startColor="@color/white"      android:endColor="@color/white"      android:angle="90" /></shape>

list_item_bg_pressed.xml

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" >    <gradient      android:startColor="@color/right_bg"      android:endColor="@color/right_bg"      android:angle="90" /></shape>

list_item.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:background="@drawable/list_selector"    android:paddingBottom="5dp"    android:paddingLeft="10dp"    android:paddingRight="10dp"    android:paddingTop="5dp" >    <ImageView        android:id="@+id/iv_icon"        android:layout_width="50dp"        android:layout_height="50dp"        android:layout_marginRight="5dp"        android:src="@drawable/wechat_icon" />    <TextView        android:id="@+id/tv_title"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/iv_icon"        android:textColor="@color/black"        android:textSize="15sp" />    <TextView        android:id="@+id/tv_msg"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignBottom="@id/iv_icon"        android:layout_alignLeft="@id/tv_title"        android:ellipsize="end"        android:singleLine="true"        android:textColor="@color/grey" />    <TextView        android:id="@+id/tv_time"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentRight="true"        android:layout_alignTop="@id/tv_title"        android:textColor="@color/grey" /></RelativeLayout>

ListView 适配器 WXAdapter代码如下：

package com.example.listviewtest.adapter;import java.util.List;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.TextView;import com.example.listviewtest.R;import com.example.listviewtest.entity.WXMessage;public class WXAdapter extends BaseAdapter {    /**     * 上下文对象     */    private Context mContext = null;    private List<WXMessage> data;    /**     * @param mainActivity     */    public WXAdapter(Context ctx,List<WXMessage> data) {        mContext = ctx;        this.data = data;    }    @Override    public int getCount() {        return 100;    }    @Override    public Object getItem(int position) {        return null;    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public View getView(final int position, View convertView, ViewGroup parent) {            ViewHolder holder;        if (convertView == null) {            convertView = LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false);            holder = new ViewHolder();                        holder.iv_icon = (ImageView) convertView.findViewById(R.id.iv_icon);            holder.tv_title = (TextView)convertView.findViewById(R.id.tv_title);            holder.tv_msg = (TextView)convertView.findViewById(R.id.tv_msg);            holder.tv_time = (TextView)convertView.findViewById(R.id.tv_time);                        convertView.setTag(holder);        } else {// 有直接获得ViewHolder            holder = (ViewHolder)convertView.getTag();        }                WXMessage msg = data.get(position);                holder.tv_title.setText(msg.getTitle());        holder.tv_msg.setText(msg.getMsg());        holder.tv_time.setText(msg.getTime());                holder.iv_icon.setImageResource(msg.getIcon_id());                return convertView;    }    static class ViewHolder {        TextView tv_title;        TextView tv_msg;        TextView tv_time;        ImageView iv_icon;    }}

MainActivity代码如下：

package com.example.listviewtest;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ListView;import com.example.listviewtest.adapter.WXAdapter;import com.example.listviewtest.entity.WXMessage;public class MainActivity extends Activity implements OnItemClickListener {private List<WXMessage> data = new ArrayList<WXMessage>();private ListView mListView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initData();findView();}private void initData() {for (int i = 0; i < 50; i++) {WXMessage msg = null;if (i % 3 == 0) {msg = new WXMessage("腾讯新闻", "人民日报刊文：习近平对评价毛泽东提6个重要观点", "早上8:44");msg.setIcon_id(R.drawable.qq_icon);} else if (i % 3 == 1) {msg = new WXMessage("订阅号", "CSDN：2013年国内最具技术影响力公司", "早上8:49");msg.setIcon_id(R.drawable.wechat_icon);} else {msg = new WXMessage("微博阅读", "美女演各款妹子跟男朋友打电话", "昨天晚上");msg.setIcon_id(R.drawable.qq_icon);}data.add(msg);}}private void findView() {mListView = (ListView) findViewById(R.id.mListView);WXAdapter mAdapter = new WXAdapter(this, data);mListView.setAdapter(mAdapter);mListView.setOnItemClickListener(this);}@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position,long id) {mListView.setItemChecked(position, true);//mListView.setSelection(position);}}

这里我们通过  ListView.setItemChecked(int position, boolean value)方法来选中被点击的Item，这时之前在list_item中设置的android:background="@drawable/list_selector"就开始生效了。

怎么样，比之前通过Adapter刷新整个ListView的效率要高很多吧！

Demo下载地址：http://download.csdn.net/detail/fx_sky/6821071