代理的使用 一（helloworld级别）

ViewWithButtons.h部分的代码。

@protocol ViewWithBuutonsDelegate<NSObject>

@required

-(void)buttonClickedWithTag:(NSInteger)tag;

@end

@interface ViewWithButtons : UIView

@property(nonatomic)id <ViewWithBuutonsDelegate> delegate;

@end

- (IBAction)buttonClick:(UIButton *)sender {

    if ([self.delegate respondsToSelector:@selector(buttonClickedWithTag:)]) {

        [self.delegate buttonClickedWithTag:sender.tag];

    }   

}

#import "ViewController.h"

#import "ViewWithButtons.h"

@interface ViewController ()<ViewWithBuutonsDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    ViewWithButtons *view = [[[NSBundle mainBundle]loadNibNamed:@"ViewWithButtons" owner:self options:nil]lastObject];

    view.delegate = self;

    [self.view addSubview:view];

    // Do any additional setup after loading the view, typically from a nib.

}

-(void)buttonClickedWithTag:(NSInteger)tag{

    NSLog(@"%lu",tag);

}