详解iOS中按钮点击事件处理方式

@interface MyView : UIView@property (strong, nonatomic) UIButton *myBtn;@end

#import "MyView.h" @implementation MyView//view的初始化方法- (id)initWithFrame:(CGRect)frame{  self = [super initWithFrame:frame];  if (self)  {  //初始化按钮    _myBtn = [[UIButton alloc] initWithFrame:CGRectMake(140, 100, 100, 50)];    _myBtn.backgroundColor = [UIColor redColor];    //将按钮添加到自身    [self addSubview:_myBtn];  }  return self;}@end

#import <UIKit/UIKit.h>@interface MyViewController : UIViewController@end

#import "MyViewController.h"#import "MyView.h"@interface MyViewController ()@property (strong, nonatomic) MyView *myview;@end@implementation MyViewController- (void)loadView{  MyView *myView = [[MyView alloc] initWithFrame: [[UIScreen mainScreen] bounds] ];  self.view = myView;  self.myview = myView;    //在controller中设置按钮的目标-动作，其中目标是self，也就是控制器自身，动作是用目标提供的BtnClick:方法，  [self.myview.myBtn addTarget:self             action:@selector(BtnClick:)        forControlEvents:UIControlEventTouchUpInside];}//MyView中的按钮的事件- (void)BtnClick:(UIButton *)btn{  NSLog(@"Method in controller.");  NSLog(@"Button clicked.");}

 #import "AppDelegate.h"#import "MyViewController.h"@interface AppDelegate ()@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    self.window = [ [UIWindow alloc] initWithFrame: [[UIScreen mainScreen] bounds ] ];    MyViewController *myVC = [[MyViewController alloc] init];  self.window.rootViewController = myVC;    self.window.backgroundColor = [UIColor whiteColor];  [self.window makeKeyAndVisible];            return YES;}

#import <UIKit/UIKit.h>//自定义的按钮协议，该协议实现了<NSObject>协议，协议的名称自定，不过不要和Apple的协议重名@protocol myBtnDelegate <NSObject>//协议中的方法，遵循该协议的类提供其具体的实现，协议有@optional和@required两个修饰符，默认情况下是@required- (void) BtnClick:(UIButton *)btn;@end//MyView的接口@interface MyView : UIView//声明一个属性，这个属性用于指定谁来成为本类的代理，由于不能确定什么类型的对象会成为本类的代理，因此声明为id类型@property (weak, nonatomic) id<myBtnDelegate> delegate;@end

#import "MyView.h"@interface MyView ()//声明在.m中的按钮对外部不可见@property (strong, nonatomic) UIButton *myBtn;@end@implementation MyView//初始化- (id)initWithFrame:(CGRect)frame{  self = [super initWithFrame:frame];  if (self)  {    _myBtn = [[UIButton alloc] initWithFrame:CGRectMake(140, 100, 100, 50)];    _myBtn.backgroundColor = [UIColor redColor];    //为按钮设置目标-动作，其中目标是self即包含该按钮的view自身，动作是有目标（view）提供的myBtnClick：方法    [_myBtn addTarget:self          action:@selector(myBtnClick:) forControlEvents:UIControlEventTouchUpInside];    [self addSubview:_myBtn];  }    return self;}//view中按钮的事件- (void)myBtnClick:(UIButton *)btn{  NSLog(@"Method in view");  //在回调代理方法时，首先判断自身的代理是否实现了代理方法，否则会导致崩溃  //如果自身代理实现了代理方法，在该方法中回调代理实现的具体的代理方法  if ( [self.delegate respondsToSelector:@selector(BtnClick:)] )  {    [self.delegate BtnClick: btn];  }  else  {    NSLog(@"BtnClick: haven't found in delegate.");  }  }@end

#import "MyViewController.h"#import "MyView.h"//声明该controller遵循 <myBtnDelegate>协议，因此需要实现协议中的方法@interface MyViewController () <myBtnDelegate>@end@implementation MyViewController- (void)loadView{  //创建MyView类型的myView  MyView *myView = [[MyView alloc] initWithFrame: [[UIScreen mainScreen] bounds] ];  //将myView的代理设置为self，即当前controller自身  myView.delegate = self;  //将controller的view指向myView  self.view = myView;}//该方法是代理中的方法，在controller中决定点击myBtn按钮后具体要做的事情，但controller并不能直接获取到myBtn- (void)BtnClick:(UIButton *)btn{  NSLog(@"Method in controller.");  NSLog(@"Button clicked.");}