Android-扩展BaseAdapter实现progressBar下载*该Demo涉及了BaseAdapter,ProgressBar,Handler,Thread,线程池；**Android-扩展BaseAdapter实现progressBar下载*1.创建listview的xml*2.创建listview中填充的xml*3.创建继承BaseAdapter的MyBaseAdapter类*4.初始化MyBaseadapter*5.向listView中添加适配器*6.创建线程池ExecutorService和资源*7.创建MyBaseadapter带参构造函数(Contextcontext)*