MRC and Arc Mixed

iOS5.0 can start with arc (Automatic Reference counting: Auto reference count) instead of the previous MRC (Manual Reference Counting: Manual reference count). Using arc will reduce the amount of code and the frustration of forgetting to release objects. But there are two sides to everything. After using arc, if you want to reuse a previously written use of the MRC class, you will get an error. What happens now? method is relatively simple, only need to do one of the following steps to solve:

Under the Targets build phases option, under compile sources, select the file that you want to compile with arc, -fno-objc-arc Double-click it, and enter

The Arc class can also be used in MRC projects. Here's how:

Under Targets's build phases option, under compile sources, select the file you want to compile with arc, double-click it, enter -fobjc-arc

MRC and Arc Mixed