listview的分类,仿京东分类

listview的分类,今天看到京东的app分类做的很ok,自己也尝试了下,效果实现了. //先上图,京东的,我自己的

//代码很容易就不过多做解释了. //主要的话就是两个方法的使用 //listview.smoothScrollToPosition(0)设置listview到排头 //listview.smoothScrollToPosition(adapter.getCount()-1);设置到底部 //listview.smoothScrollToPositionFromTop(arg2-5, 0); //滑动到中间位置(这里的5,表示如果你的屏幕一次有10个item,5的话基本上就在中间了,一个大致的位置).

//大得问题没有.还有就是选中item的方法,新人可以长点见识.

//以下是全部的代码 import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map;

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;

public class MainActivity extends Activity {

/***** 初始化数据和ID *****/ private ListView listview; private List<Map<String, String>>list = new ArrayList<Map<String,String>>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //初始化id listview = (ListView) findViewById(R.id.listview); //模拟列表集合 list = new ArrayList<Map<String,String>>(); String str[] = {"推荐分类","潮流女装","品牌男装","个护化妆","家用电器","电脑办公","手机数码", "母婴童装","图书音像","家居家纺","家具建材","食品生鲜","酒水饮料","运动户外","鞋靴箱包","奢品礼品", "钟表珠宝","玩具乐器","内衣配饰","汽车用品","医药保健","计生情趣","京东金融","生活旅行","宠物农资"}; for (int i = 0; i < str.length; i++) { Map<String, String>map = new HashMap<String, String>(); map.put("1", str[i]); list.add(map); } //自定义adapter 实现效果 final List_adapter list_adapter = new List_adapter(this, list,0); listview.setAdapter(list_adapter); listview.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { //选中的位置 list_adapter.setSeclection(arg2); //刷新listview list_adapter.notifyDataSetChanged(); //将选中位置平滑滑动到中间位置 if(arg2==0||arg2==1||arg2==2||arg2==3||arg2==4||arg2==5){ listview.smoothScrollToPosition(0);//滑动到排头 }else if(arg2==24||arg2==23||arg2==22||arg2==21||arg2==20){ listview.smoothScrollToPosition(list_adapter.getCount()-1);//滑动到底部 }else if(arg2==6||arg2==7||arg2==8||arg2==9||arg2==10||arg2==11 ||arg2==12||arg2==13||arg2==14||arg2==15||arg2==16||arg2==17 ||arg2==18||arg2==19){ listview.smoothScrollToPositionFromTop(arg2-5, 0); //滑动到中间位置 } } }); }

}

//adapter import java.util.ArrayList; import java.util.List; import java.util.Map;

import android.content.Context; import android.graphics.Color; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.RelativeLayout; import android.widget.TextView;

public class List_adapter extends BaseAdapter{

private List<Map<String, String>>list = new ArrayList<Map<String,String>>(); private Context context; //初始化位置 private int clickStatus = 0; public void setSeclection(int position) { clickStatus = position; } public List_adapter(Context context,List<Map<String, String>>list,int a1a1) { this.context = context; this.list = list; this.clickStatus = a1a1; } @Override public int getCount() { return list.size(); } @Override public Object getItem(int arg0) { return list.get(arg0); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder; if(convertView==null){ convertView = View.inflate(context, R.layout.item, null); holder = new ViewHolder(); holder.tv1 = (TextView) convertView.findViewById(R.id.tv1); holder.right_tv = (TextView) convertView.findViewById(R.id.right_tv); holder.rl1 = (RelativeLayout) convertView.findViewById(R.id.rl1); convertView.setTag(holder); }else{ holder = (ViewHolder) convertView.getTag(); } if (clickStatus==position) { holder.tv1.setText(list.get(position).get("1")); holder.tv1.setTextColor(Color.rgb(221,84,102)); holder.right_tv.setBackgroundColor(Color.rgb(244,245,247)); holder.rl1.setBackgroundColor(Color.rgb(244,245,247)); }else{ holder.tv1.setText(list.get(position).get("1")); holder.tv1.setTextColor(Color.rgb(29,29,29)); holder.right_tv.setBackgroundColor(Color.rgb(230,230,230)); holder.rl1.setBackgroundColor(Color.rgb(255,255,255)); } return convertView; } class ViewHolder{ TextView tv1; TextView right_tv; RelativeLayout rl1; }

}

//main文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:background="#f4f5f7" android:layout_height="match_parent" > <ListView android:id="@+id/listview" android:layout_width="85dp" android:layout_height="match_parent" android:background="@null" android:divider="@null" android:scrollbars="@null" ></ListView> </RelativeLayout>

//item布局

<?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="match_parent" > <RelativeLayout android:id="@+id/rl1" android:layout_width="85dp" android:layout_height="60dp" android:background="#ffffff" > <TextView android:id="@+id/tv1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:text="品牌男装" android:textColor="#1d1d1d" android:textSize="12sp" /> <TextView android:layout_width="match_parent" android:layout_height="0.5dp" android:background="#e6e6e6" /> <TextView android:layout_width="match_parent" android:layout_height="0.5dp" android:background="#e6e6e6" android:layout_alignParentBottom="true" /> <TextView android:id="@+id/right_tv" android:layout_width="1.0dp" android:layout_height="match_parent" android:background="#e6e6e6" android:layout_alignParentRight="true" /> </RelativeLayout> </RelativeLayout>

//自测有个小瑕疵,就是从下往上速率会有点快,不知是否是测试机的原因.

//就是这么多,我是安卓一年新人,很开心和大家分享,如果有更好的意见和意见可以一起交流