. Net BS system, which has been compiled and all CS code files are invisible. It is a headache to modify local code. Although reflect and other tools can be used for reverse encoding, but the code is often wrong. If it is confusing, it cannot be used. Therefore, you can solve the problem by modifying the desired ASPX page and asking it to call its own CS code file to replace the compiled code: 1. first, create a CS file corresponding to the ASPX file 2. copy the decompressed CS code to the CS file. modify Inherits = "xxxxxx" in the first sentence of the ASPX file to Inherits = "xxxxxx1", and change public partial class xxxxxx In the CS file to public partial class xxxxxx1 4. modify the CS code as needed. In this way, the ASPX page calls the CS file code to replace the code in the DLL inventory to avoid other errors that may occur when the entire DLL library is re-compiled.