C language array with dynamic size in structure-CodePudding

I have searched so much but yet hadn't found any good solution for c. I want to initialize an array with dynamic size. The solution I saw so far was a linked list but it seems it doesn't meet my requirements.

The code I had tested so far is as below

typedef struct 
{
    const unsigned char widgetCount;
    unsigned char index;
    lv_obj_t * radiobtnVIEW[widgetCount];
}AssetVIEW;

and then to initialize widgetCount

AssetVIEW View={4};

The error I get is

error: 'widgetCount' undeclared here (not in a function)

Your help is appreciated by this newbie.

CodePudding user response：

You cannot, in C, refer to other fields within the struct while it's being declared. This is what the error message refers to. As noted, you can use a pointer or a flexible array member (fam):

lv_obj_t **radiobtnVIEW;

lv_obj_t *radiobtnVIEW[];

Then dynamically allocate memory for said field:

size_t n = 4;
AssetVIEW *View = malloc(sizeof(*View)   n * sizeof(*View->radiobtnVIEW));
...
free(View);

In the fam case, the const qualifier on widgetCount doesn't make sense as you cannot initialize it.