Android ListView点击之后保持更换的背景色，实现已读功能_listview 保持背景色

        因为项目中有这样的需求：一般消息类或者资讯类的界面，都有类似于网易客户端的点击之后更换背景色，并且保持这个颜色，表示已读取该条信息。这个功能一开始觉得已经实现了，在我的另一篇博客上有：点击打开链接 后来测试人员在测试的时候，发现这样一个奇怪的问题：

       当点击了listview的第0项，背景颜色改变，并且保持着背景没错，但滑动到下一个页面的listview，原本没有点击的item，竟然莫名其妙的出现了更换的背景。。。

      出现上述的情况是因为我实现的原理是这样的：当用户点击某一个item，会进入到监听方法里面，我设置一个变量保存所选中的位置position，也就是如下代码：

	 arg1.setSelected(true);
				selectItem = arg2; // 当前选择的节目item
				
				messageAd.notifyDataSetChanged(); // 通知adapter刷新数据

     在适配器里面，我就使用if语句判断，如果position等于刚才所点击的item，则设置背景颜色，如下代码：

if (selectItem == position) {
			//设置背景
			// }

      上述设置就会出现错乱的问题，原因以后再深究，下面贴出解决的办法，不多说直接上代码，有注释：

package com.explink.listview;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
 
public class MainActivity extends Activity {
	private ListView mListView;
	private MyAdapter mAdapter;
	List<User> userList;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
		initData();
	}
	private void initView() {
		mListView = (ListView) findViewById(R.id.mListView);
	}
	private void initData() {
		User user = new User("卢磊", "13319405061");
		User user1 = new User("小明", "13319405062");
		User user2 = new User("小黄", "13319405063");
		User user3 = new User("小绿", "13319405064");
		User user4 = new User("卢磊", "13319405061");
		User user5 = new User("小明", "13319405062");
		User user6 = new User("小黄", "13319405063");
		User user7 = new User("小绿", "13319405064");
		User user8 = new User("卢磊", "13319405061");
		User user9 = new User("小明", "13319405062");
		User user10 = new User("小黄", "13319405063");
		User user11 = new User("小绿", "13319405064");
		User user12 = new User("卢磊", "13319405061");
		User user13 = new User("小明", "13319405062");
		User user14 = new User("小黄", "13319405063");
		User user15 = new User("小绿", "13319405064");
		User user16 = new User("卢磊", "13319405061");
		User user17 = new User("小明", "13319405062");
		User user18 = new User("小黄", "13319405063");
		User user19 = new User("小绿", "13319405064");
		User user20 = new User("卢磊", "13319405061");
		User user21 = new User("小明", "13319405062");
		User user22 = new User("小黄", "13319405063");
		User user23 = new User("小绿", "13319405064");
		// 一般从网络上获取的数据都是List集合
		userList = new ArrayList<User>();
		userList.add(user);
		userList.add(user1);
		userList.add(user2);
		userList.add(user3);
		userList.add(user4);
		userList.add(user5);
		userList.add(user6);
		userList.add(user7);
		userList.add(user8);
		userList.add(user9);
		userList.add(user10);
		userList.add(user11);
		userList.add(user12);
		userList.add(user13);
		userList.add(user14);
		userList.add(user15);
		userList.add(user16);
		userList.add(user17);
		userList.add(user18);
		userList.add(user19);
		userList.add(user20);
		userList.add(user21);
		userList.add(user22);
		userList.add(user23);
 
		mAdapter = new MyAdapter(MainActivity.this, userList);
		mListView.setAdapter(mAdapter);
		mListView.setOnItemClickListener(new OnItemClickListener() {
			@Override
			public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
					long arg3) {
				mAdapter.recordPosition(arg2);
				mAdapter.notifyDataSetChanged();
			}
		});
	}
	@SuppressLint("UseSparseArrays")
	public class MyAdapter extends BaseAdapter {
		private LayoutInflater inflater;
		private List<User> userList;
		private List<Integer> pList = new ArrayList<Integer>();
		public MyAdapter(Context context, List<User> userList) {
			this.inflater = LayoutInflater.from(context);
			this.userList = userList;
		}
		@Override
		public int getCount() {
			return this.userList.size();
		}
 
		@Override
		public Object getItem(int position) {
			return userList.get(position);
		}
 
		@Override
		public long getItemId(int position) {
			return position;
		}
		public void recordPosition(int position) {
			pList.add(position);
		}
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder holder;
			if (convertView == null) {
				convertView = inflater.inflate(R.layout.list_item, null);
				holder = new ViewHolder();
				holder.name_tv = (TextView) convertView
						.findViewById(R.id.name_tv);
				holder.phone_tv = (TextView) convertView
						.findViewById(R.id.phone_tv);
				convertView.setTag(holder);
			} else {
				holder = (ViewHolder) convertView.getTag();
			}
			holder.name_tv.setText(userList.get(position).getName());
			holder.phone_tv.setText(userList.get(position).getPhoneNo());
			//防止convertView复用背景，导致第二页出现灰色背景，所以在判断设定为白色
			convertView.setBackgroundColor(Color.WHITE);
			for (int i = 0; i < pList.size(); i++) {
				if (pList.get(i) == position) {
					convertView.setBackgroundColor(Color.GRAY);
				}
			}
			return convertView;
		}
		public class ViewHolder {
			public TextView name_tv;
			public TextView phone_tv;
		}
	}
}

      数据源的类为：

package com.explink.listview;
 
public class User {
	public User(){
	}
	public User(String name,String phoneNo){
		this.name = name;
		this.phoneNo = phoneNo;
	}
	private String name;
	private String phoneNo;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPhoneNo() {
		return phoneNo;
	}
	public void setPhoneNo(String phoneNo) {
		this.phoneNo = phoneNo;
	}
	
}

           资源已经上传到csdn，传送门在此： android listview已读功能  ，上一篇的博客如果有需要查看的，可以参考如下链接： android listview保持背景颜色