[转Iphone]关于self.用法的一些总结

 

MyClass.h

@interface MyClass : NSObject { MyObject * _myObject; } @property (nonatomic, retain) MyObject *myObject; @end

MyClass.m

  @synthesize myObject = _myObject; 

OK, 你现在再试下, 如果你用self._myObject = aMyObject; 或者 myObject = aMyObject; 你会得到一个错误, 为什么呢, 这里就是和Obj-c的存取方法有关了. 说白了很简单 , 大家都知道, @property (nonatomic, retain) MyObject *myObject; 是为一个属性设置存取方法, 只是平时我们用的方法名和属性名是一样的,现在你把它写成不同的名字, 就会很清楚了. _myObject是属性本身, myObject是存取方法名.

 

 

 

 

assign, retain ,copy.

get方法是:

-(MyObject*)myObject{ return _myObject; }

Set方法是:

// assign -(void)setMyObject:(id)newValue{ _myObject = newValue; } // retain -(void)setMyObject:(id)newValue{ if (_myObject != newValue) { [_myObject release]; _myObject = [newValue retain]; } } // copy -(void)setMyObject:(id)newValue{ if (_myObject != newValue) { [_myObject release]; _myObject = [newValue copy]; } }   示例：     1.加self.:   MyObject * aMyObject = [[MyObject alloc] init]; //aMyObject retainCount = 1; self.myObject = aMyObject; //myObject retainCount = 2; [aMyObject release];//myObject retainCount = 1;       2. 不加self.:   MyObject * aMyObject = [[MyObject alloc] init]; //aMyObject retainCount = 1; myObject = aMyObject; //myObject retainCount = 1; [aMyObject release];//对象己经被释放   再看直接赋值的:     3.加self.:   self.myObject= [[MyObject alloc] init]; //myObject retainCount = 2;     4. 不加self.:   myObject = [[MyObject alloc] init]; //myObject retainCount = 1;