http://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier
What are rules about using an underscore in a c identifier
+V d2h5X251bGw= 请备注：from博客园
http://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier