前言
当你要将某个从数据库或者文件中获得相当大的数据,在界面中向用户展示的时候,由于定义一个个视图比较麻烦,android中提供了类似于数组的控件–listview。
使用方法:
假设我们要转的数据是一个person对象数组
package cn.zhuangzhihuang.mylist; public class person { private string name; private string tel; public person(string name, string tel) { super(); this.name = name; this.tel = tel; } public string getname() { return name; } public void setname(string name) { this.name = name; } public string gettel() { return tel; } public void settel(string tel) { this.tel = tel; } public string tostring() { return "点击的联系人为" + this.getname() +"\n电话号码为" + this.gettel(); } }
person[] db = { new person("张三","18555555555"), new person("李四","18555555556"), new person("王五","18555555557"), new person("赵六","18555555558"), new person("邓七","18555555559") }; list<person> friend_list; friend_list = new arraylist<person>(); for(int i=0;i<db.length;i++) { friend_list.add(db[i]); }
1、首先,你需要在xml中加入一个listview控件:
<listview android:id="@+id/data_view" android:layout_width="match_parent" android:layout_height="wrap_content" > </listview>
2、接着你需要创建一个适配器myadapter类,这个适配器的作用时将你要展示的数据转成可见格式也就时view。
class myadapter extends baseadapter { @override public int getcount() { //返回表的长度 // todo auto-generated method stub return friend_list.size(); } @override public object getitem(int position) { //返回表的index位置的元组 // todo auto-generated method stub return friend_list.get(position); } @override public long getitemid(int position) { // todo auto-generated method stub return position; } @override public view getview(int position, view convertview, viewgroup parent) { //就像等到一个对象数组的某一个元素 // todo auto-generated method stub view view = view.inflate(mainactivity.this, r.layout.item, null); textview tv_item_name = (textview) view.findviewbyid(r.id.tv_item_name); textview tv_item_tel = (textview) view.findviewbyid(r.id.tv_item_tel); tv_item_name.settext(friend_list.get(position).getname()); tv_item_tel.settext(friend_list.get(position).gettel()); return view; //初始化这个listview会调用到这个方法,因为要把传进去的对象数组的每个元素转成view加入到listview中 } }
3、然后要在xml中写下你要转成的view的模板
<?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" > <textview android:id="@+id/tv_item_name" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:textsize="20sp" /> <textview android:id="@+id/tv_item_tel" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:textsize="20sp" /> </linearlayout>
4、最后在mainactivity中把listview的适配器设置一下。调用setadapter这个方法
data_view.setadapter(myadapter);
android代码:
xml:
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <linearlayout android:layout_width="match_parent" android:layout_height="wrap_content" > <textview android:id="@+id/tv1" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="姓名" android:textsize="20sp" /> <textview android:id="@+id/tv2" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="联系电话" android:textsize="20sp" /> </linearlayout> <listview android:id="@+id/data_view" android:layout_width="match_parent" android:layout_height="wrap_content" > </listview> </linearlayout>
mainactivity:
package cn.zhuangzhihuang.mylist; 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.viewgroup; import android.widget.adapterview; import android.widget.adapterview.onitemclicklistener; import android.widget.baseadapter; import android.widget.listview; import android.widget.textview; import android.widget.toast; public class mainactivity extends activity { list<person> friend_list; @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); listview data_view = (listview) findviewbyid(r.id.data_view); person[] db = { new person("张三","18555555555"), new person("李四","18555555556"), new person("王五","18555555557"), new person("赵六","18555555558"), new person("邓七","18555555559") }; friend_list = new arraylist<person>(); for(int i=0;i<db.length;i++) { friend_list.add(db[i]); } //自定义适配器 myadapter myadapter = new myadapter(); data_view.setadapter(myadapter); data_view.setonitemclicklistener(new onitemclicklistener() { @override public void onitemclick(adapterview<?> parent, view view, int position, long id) { // todo auto-generated method stub string temp = friend_list.get((int)id).tostring(); toast.maketext(mainactivity.this, temp, 0).show(); } }); } class myadapter extends baseadapter { @override public int getcount() { //返回表的长度 // todo auto-generated method stub return friend_list.size(); } @override public object getitem(int position) { //返回表的index位置的元组 // todo auto-generated method stub return friend_list.get(position); } @override public long getitemid(int position) { // todo auto-generated method stub return position; } @override public view getview(int position, view convertview, viewgroup parent) { //就像等到一个对象数组的某一个元素 // todo auto-generated method stub view view = view.inflate(mainactivity.this, r.layout.item, null); textview tv_item_name = (textview) view.findviewbyid(r.id.tv_item_name); textview tv_item_tel = (textview) view.findviewbyid(r.id.tv_item_tel); tv_item_name.settext(friend_list.get(position).getname()); tv_item_tel.settext(friend_list.get(position).gettel()); return view; //初始化这个listview会调用到这个方法,因为要把传进去的对象数组的每个元素转成view加入到listview中 } } }
效果:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持移动技术网。
如对本文有疑问, 点击进行留言回复!!
荐 面试官:kafka日志段如何读写都不知道,好意思说精通Kafka吗?
荐 如何写出一份“有理有据使人信服”的Android项目设计文档
荐 灵魂一问,Android中有代替HashMap的方法吗?
intent.setFlag的参数 FLAG_ACTIVITY_CLEAR_TASK 说明
网友评论