说明：  在ListView中添加ProgressBar。演示如何在ListView中为其ListItem添加一个ProgressBar，其实没有特别的思路，就是动态建立ProgressBar，然后移动其位置即可
(ListView add in the ProgressBar. Demonstration of how to add ListItem for the ListView in a ProgressBar, in fact, no particular line of thought is the dynamic establishment of ProgressBar, and then move to the location)