Objective-c委托

@protocol UIBViewDelegate <NSObject>

@optional

- (void)ontouch:(UIScrollView *)scrollView; //声明协议方法

@end

@interface BView : UIScrollView<UIScrollViewDelegate>

{

 id< UIBViewDelegate > _touchdelegate; //设置委托变量

}

@property(nonatomic,assign) id< UIBViewDelegate > _touchdelegate;

@end

B_View.mm:

@synthesize _touchdelegate;

- (id)initWithFrame:(CGRect)frame {

if (self = [super initWithFrame:frame]) {

 // Initialization code

 _touchdelegate=nil;

 }

 return self;

}

- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event

{

 [super touchesBegan:touches withEvent:event];

 if(_touchdelegate!=nil && [_touchdelegate respondsToSelector: @selector(ontouch:) ] == true)

  [_touchdelegate ontouch:self];  //调用协议委托

}

@end
A_View.h:
@interface AViewController : UIViewController < UIBViewDelegate >

{

 BView *m_BView;

}

@end

A_View.mm:

- (void)viewWillAppear:(BOOL)animated

{

 m_BView._touchdelegate = self; //设置委托

 [self.view addSubview: m_BView];

}

- (void)ontouch:(UIScrollView *)scrollView

{

    //实现协议

}