Just encountered a problem when writing the program, just want to compile all the .cs files into .dll. (Because since the development, I have not tried it to compile it, just know that there is such a thing. Maybe the company has nothing to do!) (说 白, people lazy! ^ O ^). Ok, return to the topic, I really don't know how to compile, I only know the CSC command. Ah! When starting in the start -> 游> -> CMD, the system has prompted anything wrong! This is a strange thing! So then find it, search the C disk: csc.exe, finally found! ^ o ^! OK, you can compile it now! CSC / Target: library * .csok has been compiled! Happy in ING ............... I then try again to see all .s DELETE, can you still run! Oh! It's really! Still in joy, ING ......................................................................................................................................................... ? ? The problem is coming! The program is still normal! Confuse ing ........ This makes me think of IIS. So restart it. Run the program again. ? ? Strange, or you can run normally! That takes all the procedures to another directory! Haha! Finally, I finally became wrong! But look at the mistake! It's a bit dizzy! The error message is this sentence: