How to add an external header file in vs?

Reference link ：https://www.jianshu.com/p/bd17b153dae2

vs How to add an external header file in ？
Method 1 ：
With Sales_item.h File as an example ：
（1） Directly copy the external header file , Under this item, it is the same as this item cpp Files in the same directory , Here's the picture ：

（2） At the project header file , Right click —— Add an existing item , Find out Sales_item.h File and add , Here's the picture ：

（3） Write in program #include"Sales_item.h", Here's the picture ：

Method 2 ：

（1） Item right click , In the attribute C/C++ ----- routine , The attachment contains the path to the directory where the header file is added

（2） Write in program #include"Sales_item.h", Here's the picture ：

Be careful ：（1） The directory path of the header file added in must be （2） in include“…” The upper level file of ;（2） There are multiple layers of files in / separate