What is the mean of definition of INVALID_HANDLE_VALUE

[kimi]

#define INVALID_HANDLE_VALUE ((HANDLE)(ULONG_PTR)-1)

so, What number of INVALID_HANDLE_VALUE is? Why does it mean invalid handle?
thank you !

[William DePalo [MVP VC++]]

Post by kimi
#define INVALID_HANDLE_VALUE ((HANDLE)(ULONG_PTR)-1)
so, What number of INVALID_HANDLE_VALUE is? Why does it mean invalid handle?

Some API functions, such as CreateFile() are defined to return a handle. If
a handle with a "value" of -1 is returned it means that the function failed.

Regards,
Will

[Scott McPhillips [MVP]]

Post by kimi
#define INVALID_HANDLE_VALUE ((HANDLE)(ULONG_PTR)-1)
so, What number of INVALID_HANDLE_VALUE is? Why does it mean invalid handle?
thank you !

It is -1, but it is not a number type. It is a HANDLE type. It means
invalid handle because that is what Microsoft returns if they detect an
invalid handle from your code.