anroid ListView描述

1.listView就是列表形式的View,展示形式:  数据+适配器

 常见的自带ArrayAdapter，SimpleAdapter等等,但是大多情况都是自己自定义.

自定义listview的适配器

Item项  icon_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="vertical" >
    
    <RelativeLayout 
        android:id="@+id/rl_item_all"
        android:layout_width="match_parent"
        android:layout_height="144dp"
        android:background="#ffffff"
        android:gravity="center_vertical"
        >
        <ImageView 
            android:id="@+id/iv_item_icon"
            android:layout_width="120dp"
            android:layout_height="120dp"
            android:layout_marginTop="15dp"
            android:layout_marginLeft="24dp"
            android:background="@drawable/head_man"
            />
        <TextView 
            android:id="@+id/tv_item_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft=182dp"
            android:text="奥巴马"
            android:textSize="38dp"
            android:layout_centerVertical="true"
            />
    </RelativeLayout>
</LinearLayout

public class IconShowAdapter extends BaseAdapter

{

private Context context;

       //Entity为实体对象,填充listView数据

        private List<Entity> list=new ArrayList<Entity>();

public  IconShowAdapter(Context context)

{

this.context=context;

}

//确定listView中显示的数据条目

@Overide

public int getCount()

{

return list.Size();
}

@Overide

public Object getItem(int position)

{

return list.get(position);

}

@Overide 

public long getItem(int position)

{

return position;

}

//使用内部类ViewHolder构建临时View,重中View,减少刷新listView数据所占内存

//当然ViewHoler也设为static

@Overide

public View getView(int position ,View convertView,ViewGroup parent)

{

View view=null;

ViewHolder holder=null;

final Entity entity=list.get(position);

if(convertView==null)

{

view=LayoutInflater.from(context).inflate(R.id.icon_item.xml);

holder=new ViewHolder();

holder.iv_icon=(ImageView)view.findViewById(R.id.iv_item_icon);

holder.tv_name=(TextView)view.findViewById(R.id.tv_item_name);

view.setTag(holder);

}

else

{

view=convertView.

holder=(Viewholder)view.getTag();

}

holder.iv_icon.setBackgroundResource(R.drawble.head_man);

holder.tv_name.setText(entity.getName());

return view;

}

public class ViewHolder

{

ImageView iv_icon;

TextView tv_name;

}

//用户刷新listView数据

public void flushData(List<Entity> list)

{

if(list!=null)

{

this.list=list;

this.notifyDataSetChanged();

}
}

}