摘要:
assign:用于“纯量类型”(如CGFloat 或 NSInteger等); strong:用于“对象类型”,定义了一种“拥有关系”(owning relationship),为这种属性设置新值时,设置方法会先保留新值,并释放旧值,然后再将新值设置上去; weak:用于“对象类型”,定义了一种“非 阅读全文
摘要:
Declaring a property atomic makes compiler generate additional code that prevents concurrent access to the property. This additional code locks a sema 阅读全文