说明：  C# 与ASP.NET初识教程清淅版 PDF，主讲一些基础点的知识，像C#语言基础，程序设计基础，数据类型、变量常量、类型转换、表达式、流程控件、方法、域和属性、继承、事件索引、接口、组织应用程序、文件操作、高级话题、以及一些C#关键字和错误码附录等
(C # and ASP.NET first-time tutorial PDF version, mainly talk about some basic knowledge, such as C # language foundation, programming foundation, data types, variable constants, type conversion, expressions, process controls, methods, fields and properties, Inheritance, event indexing, interfaces, organizing applications, file operations, advanced topics, and some C # keywords and error code appendixes, etc.)