In the afternoon, I played reflexil v1.2, which is too strong. You can change the inheritance class, add methods, fields, events, and "replace all with code, you can directly replace the functions in method with the code snippets of C.
In addition, the sub-class calls the method of the parent class. In msil, the "parent class: method name" is directly used, and it seems that non-virtual calls call the callvirt command.
Also, if the signature is used, it will retain the original one, overwrite the pfx, and remove the signature. I chose to keep the original one, but this is my own program. The signature has been registered on the computer and I don't know if there will be problems with changing others' signature DLL.
Finally, simpleassemblyexplorer also has some features, but it does not seem to be able to change the inheritance class, add methods, fields, and events. The code can be imported into another DLL. However, I heard that reflector 7 is not very good at Chinese. Keep it for use.