In C language, after the struct pointer is passed into the function, the memory address remains unchanged and the memory data changes.

In C language, after the struct pointer is passed into the function, the memory address remains unchanged and the memory data changes:

Rgbblockinfo_t * rgbblockinfo = NULL;

/* Obtain the address */

Rgbblockinfo = filetorgbbufblock (rgbbufinfo, "d :\\ picdata \ pens. RGB ");

/* Pass the address to the function */

Rgbfilewrite (rgbblockinfo, "d: \ picdata \ pens2.rgb ");

After passing in the function, the memory address remains unchanged, but the data pointed to by the memory address changes.

Before import:

After passing in:

So, as a cainiao, I am wondering where to modify the memory value?

 

I have studied it today. In the filetorgbbufblock function, the local variable rgbblockinfo_t rgbbuf is defined, and the address of the local variable is returned through return.

The problem occurs here because rgbbuf is a local variable and will be released after the function is called. Therefore, the value in the memory will be released.