1. Use WPF to build your own 3d gis software (non-axhost mode) (11) Animation system in SDK
https://blog.csdn.net/xtgmd168/article/details/85344587
2. Database optimization-SQL optimization
https: //blog.csdn.net/jianzhang11/article/details/102867120
3.WPF custom step
https://blog.csdn.net/dxm809/article/details/79735895
4.C # online preview the document (word, pdf, excel, etc.)
https://www.csdn.net/gather_27/MtjaEg0sNC1ibG9n.html
5. WeChat applet case is most complete finishing
https://www.jianshu.com/p/4a6cac171de0
6. DES encryption and decryption tool and code
https: //www.cnblogs.com/erwin/archive/2009/04/14/1435288.html
