Objective-c Objects and core Foundation objects

Core Foundation objects are primarily used in the core Foundation framework written in C and reference the counted objects. There are very few differences with OBJECTIVE-C objects. No matter which framework generates the object, once generated, Can be used in both frameworks. This conversion does not require additional CPU resources and is also known as a "Free bridge".

/**************************** (1) ***********************/

/*

Cftyperef Cfbridgingretain (id X) {

Return (__bridge_retained cftyperef) X;

}

ID cfbridgingrelease (cftyperef X) {

return (__bridge_transfer ID) X;

}

*/

cfmutablearrayref cfobject = NULL;

{

ID obj = [[nsmutablearrayalloc] init];

Cfobject =cfbridgingretain(obj);

// You can also use Cfobject = (__bridge_retained cfmutablearrayref) obj;

/*

Does the ARC mechanism work in the Core Foundation framework ?

The output is printed as follows :

Retain count = 2

Retain count = 1

So the ARC mechanism does not work under the Core Foundation

*/

Cfshow (Cfobject);

printf ("Retain count =%ld\n",cfgetretaincount(cfobject));

}

printf("Retain count =%ld\n",cfgetretaincount(cfobject));

Cfrelease (Cfobject);

/**************************** (2) ***********************/

// use __bridge conversion to replace Cfbridgingretain or __bridge_retained conversion

/*

Cfobject = (__bridge cfmutablearrayref) obj;

However, the use of __bridge does not alter the holding of objects .

*/

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Objective-c Objects and core Foundation objects