Objective C - 使用ARC定制setter？

Question

以下是我以前编写自定义保留 setter的方法:

- (void)setMyObject:(MyObject *)anObject
{
   [_myObject release], _myObject =  nil;
   _myObject = [anObject retain];

   // Other stuff
}

当属性设置为strong时,如何使用ARC实现此目的.如何确保变量具有强指针？

Answer 1

在strong对伊娃水平需要照顾自己,所以你可以仅仅做

- (void)setMyObject:(MyObject *)anObject
{
   _myObject = anObject;
   // other stuff
}

就是这样.

注意:如果你这样做没有自动属性,那么ivar就是

MyObject *_myObject;

然后ARC会为您处理保留和发布(谢天谢地).__strong默认情况下是限定符.

Answer 2

只是总结一下答案

.h文件

//If you are doing this without the ivar
@property (nonatomic, strong) MyObject *myObject;

.m文件

@synthesize myObject = _myObject;

- (void)setMyObject:(MyObject *)anObject
{
    if (_myObject != anObject)
    {
        _myObject = nil;
        _myObject = anObject;
    }
    // other stuff
}