Android UI设计--ListView的item选中效果

有时app会需要点击某个item并实现选中的效果，例如做pad时用Fragment实现的左侧列表右侧内容的效果，点击左侧某一个item后会高亮选中

有时简单的使用setSelected(boolean b)或setSelection(int position)会不成功，需要重写Adapter，并在getView中进行处理

package com.example.selectitemtest;



import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;



import android.app.Activity;

import android.content.Context;

import android.graphics.Color;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AbsListView;

import android.widget.AdapterView;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.TextView;

import android.widget.Toast;



public class MainActivity extends Activity {

    private ListView lv;

    private List<Map<String, Object>> data;

    private MyAdapter adapter;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        lv = (ListView)findViewById(R.id.lv);

        //获取将要绑定的数据设置到data中

        data = getData();

        adapter = new MyAdapter(this);

        lv.setAdapter(adapter);

        lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);

        lv.setOnItemClickListener(new ListView.OnItemClickListener() {



            @Override

            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,

                    long arg3) {

                Toast.makeText(getApplicationContext(), "click position:"+arg2, Toast.LENGTH_SHORT).show();

                adapter.setSelectedItem(arg2); //adapter.notifyDataSetInvalidated();

            }

        });

    }

     private List<Map<String, Object>> getData()

        {

            List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

            Map<String, Object> map;

            for(int i=0;i<10;i++)

            {

                map = new HashMap<String, Object>();

                map.put("img", R.drawable.ic_launcher);

                map.put("title", "花郎");

                map.put("info", "动力源于兴趣...");

                list.add(map);

            }

            return list;

        }

        

        //ViewHolder静态类

        static class ViewHolder

        {

            public ImageView img;

            public TextView title;

            public TextView info;

        }

        

        public class MyAdapter extends BaseAdapter

        {    

            private LayoutInflater mInflater = null;

            private int selectedItem = -1;

            private MyAdapter(Context context)

            {

                //根据context上下文加载布局，这里的是Demo17Activity本身，即this

                this.mInflater = LayoutInflater.from(context);

            }



            @Override

            public int getCount() {

                //How many items are in the data set represented by this Adapter.

                //在此适配器中所代表的数据集中的条目数

                return data.size();

            }



            @Override

            public Object getItem(int position) {

                // Get the data item associated with the specified position in the data set.

                //获取数据集中与指定索引对应的数据项

                return position;

            }

            

            public void setSelectedItem(int selectedItem) { this.selectedItem = selectedItem; }



            @Override

            public long getItemId(int position) {

                //Get the row id associated with the specified position in the list.

                //获取在列表中与指定索引对应的行id

                return position;

            }

            

            //Get a View that displays the data at the specified position in the data set.

            //获取一个在数据集中指定索引的视图来显示数据

            @Override

            public View getView(int position, View convertView, ViewGroup parent) {

                ViewHolder holder = null;

                //如果缓存convertView为空，则需要创建View

                if(convertView == null)

                {

                    holder = new ViewHolder();

                    //根据自定义的Item布局加载布局

                    convertView = mInflater.inflate(R.layout.list_item, null);

                    holder.img = (ImageView)convertView.findViewById(R.id.img);

                    holder.title = (TextView)convertView.findViewById(R.id.tv);

                    holder.info = (TextView)convertView.findViewById(R.id.info);

                    //将设置好的布局保存到缓存中，并将其设置在Tag里，以便后面方便取出Tag

                    convertView.setTag(holder);

                }else

                {

                    holder = (ViewHolder)convertView.getTag();

                }

                holder.img.setBackgroundResource((Integer)data.get(position).get("img"));

                holder.title.setText((String)data.get(position).get("title"));

                holder.info.setText((String)data.get(position).get("info"));

                if(position == selectedItem) { //convertView.setBackgroundColor(Color.BLUE); //convertView.setSelected(true); convertView.setBackgroundResource(R.drawable.all_listentry_left_selected); }else { //convertView.setBackgroundColor(Color.GRAY); //convertView.setSelected(false); convertView.setBackgroundResource(R.drawable.lstview); } return convertView;

            }

            

        }

}

代码中红色标注处就是重点，lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);这句话必须要加

Defines the choice behavior for the List. By default, Lists do not have any choice behavior (CHOICE_MODE_NONE). By setting the choiceMode to CHOICE_MODE_SINGLE, the List allows up to one item to be in a chosen state. By setting the choiceMode to CHOICE_MODE_MULTIPLE, the list allows any number of items to be chosen.

实现效果如下