ListView_适配器之万能适配器_实现多个ListView公用同一个适配器

相信接触过开发的人一定会接触ListView，相信接触过ListView的人一定接触过BaseAdapter，相信接触过BaseAdapter的人一定很痛恨编写适配器，因为它的数量往往跟ListView的总数是成正比的，所以我今天给大家介绍一款神器，万能适配器！

在自定义适配器的时候，我们通常会自定义一个ViewHolder类，虽然这个名字是随便起的，但是就像约定俗成一样，我们还是这么用了这么多年！当然，自定义万能适配器，从它-ViewHolder开始，我们把所有与ViewHolder有关的操作都封装起来，这样在我们的适配器中，getView中的操作就会简单很多。

packagecom.ctgu.adapter;

importandroid.content.Context;

importandroid.util.SparseArray;

importandroid.view.LayoutInflater;

importandroid.view.View;

importandroid.view.ViewGroup;

publicclassViewHolder{

privateSparseArray<View>mView;

privateintmPosition;

privateViewmConvertView;

/**

*参数说明

*@paramcontext上下文

*@paramparentViewGroup

*@paramlayoutId布局文件

*@paramposition当前position

*/

publicViewHolder(Contextcontext,ViewGroupparent,intlayoutId,

intposition){

this.mPosition=position;

this.mView=newSparseArray<View>();

mConvertView=LayoutInflater.from(context).inflate(layoutId,parent,

false);

mConvertView.setTag(this);

}

/**

*@paramcontext

*@paramconvertView

*@paramparent

*@paramlayoutId

*@paramposition

*@return返回一个ViewHolder

*/

publicstaticViewHolderget(Contextcontext,ViewconvertView,

ViewGroupparent,intlayoutId,intposition){

if(convertView==null){

returnnewViewHolder(context,parent,layoutId,position);

}else{

ViewHolderholder=(ViewHolder)convertView.getTag();

holder.mPosition=position;

returnholder;

}

}

/*

*通过viewId获取控件

*/

public<TextendsView>TgetView(intviewId){

Viewview=mView.get(viewId);

if(view==null){

view=mConvertView.findViewById(viewId);

mView.put(viewId,view);

}

return(T)view;

}

/**

*返回视图

*@return

*/

publicViewgetmConvertView(){

returnmConvertView;

}

}

然后我们自定义自己的万能适配器

packagecom.example.day19_viewholder;

importjava.util.List;

importandroid.content.Context;

importandroid.view.LayoutInflater;

importandroid.view.View;

importandroid.view.ViewGroup;

importandroid.widget.BaseAdapter;

publicabstractclassCommonAdapters<T>extendsBaseAdapter{

protectedContextcontext;

protectedList<T>list;

protectedLayoutInflaterinflater;

protectedintlayoutid;

publicCommonAdapters(Contextcontext,List<T>list,intlayoutid){

this.context=context;

this.inflater=LayoutInflater.from(context);

this.list=list;

this.layoutid=layoutid;

}

@Override

publicintgetCount(){

//TODOAuto-generatedmethodstub

returnlist==null?0:list.size();

}

@Override

publicObjectgetItem(intposition){

//TODOAuto-generatedmethodstub

returnlist==null?null:list.get(position);

}

@Override

publiclonggetItemId(intposition){

//TODOAuto-generatedmethodstub

returnposition;

}

@Override

publicViewgetView(intposition,ViewconvertView,ViewGroupparent){

ViewHolderholder=ViewHolder.get(context,convertView,parent,

layoutid,position);

convert(holder,getItem(position));

returnholder.getmConvertView();

}

publicabstractvoidconvert(ViewHolderholder,Objectt);

}

其中，我们对外提供一个方法让调用者对控件进行获取并赋值操作。

这样就两个类就完成了万能适配器的制作，下面我们来使用下！

下面是MainAdapter.java

packagecom.example.day19_viewholder;

importjava.util.List;

importandroid.content.Context;

importandroid.widget.TextView;

publicclassMyAdapterextendsCommonAdapters<Jokes>{

publicMyAdapter(Contextcontext,List<Jokes>list){

super(context,list,R.layout.listview_item_jokes);

//TODOAuto-generatedconstructorstub

}

@Override

publicvoidconvert(ViewHolderholder,Objectt){

Jokesjoke=(Jokes)t;

((TextView)holder.getView(R.id.tv_jokes_title)).setText(joke.getTitle());

((TextView)holder.getView(R.id.tv_jokes_time)).setText(joke.getTime());

((TextView)holder.getView(R.id.tv_jokes_source)).setText(joke.getSource());

((TextView)holder.getView(R.id.tv_jokes_content)).setText(joke.getContent());

}

}

下面是MainActivity.java

packagecom.example.day19_viewholder;

importjava.util.ArrayList;

importjava.util.List;

importandroid.app.Activity;

importandroid.os.Bundle;

importandroid.view.Menu;

importandroid.widget.ListView;

publicclassMainActivityextendsActivity{

privateListViewlistview;

privateMyAdapteradapter;

privateList<Jokes>list;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

listview=(ListView)findViewById(R.id.id_lv);

list=newArrayList<Jokes>();

//添加数据

for(inti=0;i<10;i++){

Jokesj=newJokes("title"+i,"土豆","2015/9/8","你是可爱的小苹果");

list.add(j);

}

adapter=newMyAdapter(this,list);

listview.setAdapter(adapter);

}

@Override

publicbooleanonCreateOptionsMenu(Menumenu){

//Inflatethemenu;thisaddsitemstotheactionbarifitispresent.

getMenuInflater().inflate(R.menu.main,menu);

returntrue;

}

}

下面是Jokes.java

packagecom.example.day19_viewholder;

publicclassJokes{

privateStringtitle;

privateStringsource;

privateStringtime;

privateStringcontent;

publicJokes(){

//TODOAuto-generatedconstructorstub

}

publicJokes(Stringtitle,Stringsource,Stringtime,Stringcontent){

super();

this.title=title;

this.source=source;

this.time=time;

this.content=content;

}

publicStringgetTitle(){

returntitle;

}

publicvoidsetTitle(Stringtitle){

this.title=title;

}

publicStringgetSource(){

returnsource;

}

publicvoidsetSource(Stringsource){

this.source=source;

}

publicStringgetTime(){

returntime;

}

publicvoidsetTime(Stringtime){

this.time=time;

}

publicStringgetContent(){

returncontent;

}

publicvoidsetContent(Stringcontent){

this.content=content;

}

}

最后附上效果图，说明是没有问题的，哈哈！





最后附上源码下载地址，当然是不需要积分就可以下载的，知识就是要分享嘛！

源码下载地址:http://download.csdn.net/detail/u010998327/9114647