Unable to open include file: "*. H": no such file or directory

AboutUnable to open include file: "*. H": no such file or directory

I encountered this problem today, but it has not been done well for a long time. However, after hard work, I still solved the problem. The record is as follows:

First, I want to know if the header file name is wrong?

Second, if we write our own header file, we must write it in the form of # include "*. H.

Third, when we directly add files from other places to our project, we must ensure that those files will also be moved to our project directory, otherwise, the above problems may occur.