Android中自定义Adapter

虽然android类库给我们提供了很多与ListView适配的Adapter并且使用起来非常方便，但是想要开发出美观的程序，自带的是不够的所以我们要重写Adapter。
1.继承BaseAdapter类
2.重写getView()--每一项显示成什么样有它决定
3.重写getCount()--一共有多少项由它决定
4.实现OnItemClickListener事件--为每一项添加事件实现onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3)事件。
下面是一个简单的例子：

package net.my.jokebook;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.text.Html;
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.LinearLayout;
import android.widget.ListView;
import android.widget.RatingBar;
import android.widget.TextView;
public class Default extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.deaultxml);
List<String> list = new ArrayList<String>();
list.add("aa");
list.add("bb");
//得到想要填充的ListView
ListView lv =(ListView)findViewById(R.id.lvjokes);
RatingAdapter adapter = new RatingAdapter(this,list);
//此处必须为通过上面这种方式new的RatingAdapter否则listInner会为空
//为ListView添加事件
lv.setOnItemClickListener(adapter);
lv.setAdapter(adapter);
}
//定义一个内部类继承BaseAdapter类并实现OnItemClickLister接口
class RatingAdapter extends BaseAdapter implements OnItemClickListener
{
LayoutInflater layoutInflater;
String inflater = Context.LAYOUT_INFLATER_SERVICE;
private List<String> listInner = null;
public RatingAdapter(Context context)
{}
public RatingAdapter(Context context,List<String> list){
layoutInflater = (LayoutInflater) context
.getSystemService(inflater);
this.listInner = list;
}
public int getCount() {
//通过此项决定ListView一共有多少Item
return listInner.size();
}
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return listInner.get(arg0);
}
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
//为每一项中的控件赋值,每一项显示的数据有它决定
public View getView(int arg0, View arg1, ViewGroup arg2) {
//得到模板布局文件对象 ,并为其中的控件赋值
LinearLayout linearLayout = (LinearLayout) layoutInflater.inflate(
R.layout.defaultmodel, null);
TextView tvTitle = (TextView)linearLayout.findViewById(R.id.tvTitle);
//tvTitle.setText(list.get(arg0));
tvTitle.setText(Html.fromHtml("<font color=\"#0000ff\">"+listInner.get(arg0)+"</font>"));
TextView tvContent = (TextView)linearLayout.findViewById(R.id.tvContent);
//此处直接给内容了
tvContent.setText("Content");
RatingBar rbLeavel =(RatingBar)linearLayout.findViewById(R.id.rbLevel);
rbLeavel.setRating(Float.parseFloat("4.0"));
return linearLayout;
}
//实现onItemClick()方法
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
//对单击每一项的处理
new AlertDialog.Builder(Default.this).setTitle(listInner.get(arg2)).setMessage(String.valueOf(arg3)).show();

}

}

}
布局文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android=" http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ListView
android:id="@+id/lvjokes"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
></ListView>
</LinearLayout>
每项布局文件(模板)：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android=" http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:orientation="vertical"
android:layout_height="wrap_content">
<TextView android:id="@+id/tvTitle"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<RelativeLayout
android:id="@+id/llDes"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView android:id="@+id/tvContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<RatingBar android:id="@+id/rbLevel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/ratingBarStyleSmall"
android:layout_alignParentRight="true"
android:rating="3"
android:numStars="5"
></RatingBar>
</RelativeLayout>
</LinearLayout>

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