ListView中的单选

今天项目中用到了ListView显示的每个条目中加入单选按钮。

实现原理就是在Adapter中加入计数器，初始值是-1.每次点击条目将条目的索引赋值给计数器，如果点击条目时索引和计数器是相等的则为取消点击状态。每次点击时候从新刷新Adapter。

下面先看下Adapter中的代码

import java.util.List;
import android.content.Context;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
/** 
 * @author quzy 
 *
 * @Description 
 *
 * @version 创建时间：2016-3-7 下午6:59:43
 */
public class MyAdapter extends BaseAdapter{
	
	private List<String>list;
	private Context context;
	private int selected = -1;
	
	public int getSelected() {
		return selected;
	}
	public void setSelected(int selected) {
		this.selected = selected;
	}
	public MyAdapter(Context context,List<String> list)
	{
		this.context = context;
		this.list = list;
	}
	@Override
	public int getCount() {
		return list.size();
	}
	@Override
	public Object getItem(int position) {
		return null;
	}
	@Override
	public long getItemId(int position) {
		return 0;
	}
	@Override
	public View getView(final int position, View convertView, ViewGroup parent) {
		ViewHolder viewHolder;
		if(convertView == null){
			viewHolder = new ViewHolder();
			convertView = View.inflate(context, R.layout.item, null);
			viewHolder.iv = (ImageView) convertView.findViewById(R.id.iv);
			viewHolder.tv = (TextView) convertView.findViewById(R.id.tv);
			convertView.setTag(viewHolder);
		}else{
			viewHolder = (ViewHolder) convertView.getTag();
		}
		viewHolder.tv.setText(list.get(position));
		if(selected == position){//设置为选中
			viewHolder.iv.setImageResource(R.drawable.coupon_select);
		}else {//设置为未选中
			viewHolder.iv.setImageResource(R.drawable.coupon_unselect);
		}
		viewHolder.iv.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				if(selected == position){//点击条目前已经是选中状态，则取消
					setSelected(-1);
				}else{//点击条目前已经是未选中状态，则取消
					setSelected(position);
				}
				notifyDataSetChanged();
			}
		});
		return convertView;
	}
	
	static class ViewHolder{
		ImageView iv;
		TextView tv;
	}

}
           

布局文件item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >
    <ImageView 
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    <TextView 
        android:id="@+id/tv"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />
</LinearLayout>
           

主界面MainActivity

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

public class MainActivity extends Activity {
	private ListView lv;
	private Button btn;
	private List<String> list;
	private MyAdapter adapter;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
		initData();
		adapter = new MyAdapter(this, list);
		lv.setAdapter(adapter);
		btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				if(adapter.getSelected()==-1){
					Toast.makeText(MainActivity.this, "还未选择", 0).show();
				}else {
					Toast.makeText(MainActivity.this, list.get(adapter.getSelected()), 0).show();
				}
			}
		});
	}
	private void initData() {
		list = new ArrayList<String>();
		for(int i = 0;i<30 ; i++){
			list.add(i+"");
		}
	}
	private void initView() {
		lv = (ListView) findViewById(R.id.lv);
		btn = (Button) findViewById(R.id.btn_click);
	}

}
           

布局文件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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.listviewsingle.MainActivity" >

    <ListView 
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ></ListView>
	<Button 
	    android:id="@+id/btn_click"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:layout_alignParentBottom="true"
	    android:layout_centerHorizontal="true"
	    android:text="click me"
	    />
</RelativeLayout>
           

效果图：

源码地址：http://download.csdn.net/detail/linder_qzy/9457471