如果某类成员不需要获得或固定的职能,那么他们的财产和综合财产就毫无意义了吗?
I have a UIToolbar that needs three buttons in a radio style, meaning that of the three, only one button can be pushed at a time. The documentation makes reference to the possibility of setting up ...
如果某类成员不需要获得或固定的职能,那么他们的财产和综合财产就毫无意义了吗?
即便这些财产是在执行之外获得的,也往往有助于执行本身。
举例来说,你已经投了票。
@interface SomeObject : NSObject {
NSThing *thing;
}
@end
@implementation SomeObject
- (id)init {
if((self = [super init]))
thing = [[NSThing someThing] retain];
return self;
}
- (void)someMethod {
if(thing)
[thing release];
thing = [[NSThing someOtherThing] retain];
}
// etc etc
@end
为什么你们想对是否分配了<代码>thing>、thing
、将其留给其他部分以及随后的retain
进行检查。 当你能够干:时:
- (id)init {
if((self = [super init]))
[self setThing:[NSThing someThing]];
return self;
}
- (void)someMethod {
[self setThing:[NSThing someOtherThing]];
}
如果你不想让这些财产在贵阶层之外获得,你就可以使用一类财产。
@interface SomeObject ()
@property (retain) NSThing *thing;
@end
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