本节学习内容：
1.事件响应链的概念
2.事件响应链的传递机制
3.事件响应链的应用
响应顺序 Subview>MainView>UIView>VCRoot>MyWindow>UIApplication>AppDelegate
1.添加一个视图控制器命名为VCRoot
【VCRoot.h】
#import<UIKit/UIKit>
#import"MainView.h"
#import"subView.h"
@interface VCRoot:UIViewConroller{
//主视图定义
MainView * _mainView
//子视图对象定义
SubView* _subView;
}
@end
【VCRoot.m】
#import"VCRoot.h"
@interface VCRoot()
@end
@implementation VCRoot
-(void)viewDidLoad{
[super viewDidLoad];
//创建主视图
_mainView=[[MainView alloc]init];
_mainView.frame=CGRectMAke(50,50,200,300);
_mainView.backgroundColor=[UIColor orangeColor];
[self.view addSubview:_mainView];
//创建子视图
_subView=[[subView alloc]init];
_subView.frame=CGRectMake(30,30,100,200);
[_mainView addSubview:_subView];
[self.view addSubview:_mainView];
//改变视图背景颜色
self.view.backgroundColor=[UIColor blueColor];
}
//当点击屏幕时，调用此函数
-(void)touchesBegan:(NSSet<UITouch*>*)touches withEvent:(UIEvent *)event{
NSLog(@"RootView 事件响应！");
}
2.创建一个主视图命名为:mainview
#import"MainView.h"
@iplementation MainView
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
NSLog(@"MainView 事件响应！next==@%",self.nextResponder);
//手动响应下传递
[super touchesBegan:touches withEvent:event];
}
3.创建一子视图命名为SubView
【SubView.m】
#import"subView.h"
@implementation subView
//在子视图中优先级最高,当响应事件，事件到此结束-
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
NSLog(@"SubView 事件响应！next==@%",self.nextResponder);
//手动响应下传递
[super touchesBegan:touches withEvent:event];
}
4.创建一个Window命名为MyWindow
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
NSLog(@"MyWindow事件响应！next==@%",self.nextResponder);
//手动响应下传递
[super touchesBegan:touches withEvent:event];
}
5.创建一个UIApplication命名为MyApplication
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
NSLog(@"MyApplication 事件响应！next==@%",self.nextResponder);
//手动响应下传递
[super touchesBegan:touches withEvent:event];
}
【AppDelegate.m】
#import"AppDelegate.h"
#import"VCRoot.h"
#import"Myapplication.h"
#import"MyWindow.h"
@interface AppDelegate()
@end
@implementation AppDelegate
//appdelegate是最后一个响应
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
NSLog(@"MyApplication 事件响应！next==@%",self.nextResponder);
//手动响应下传递
[super touchesBegan:touches withEvent:event];
}
-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
//创建一个window对象
self.window=[[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
//根视图控制器创建
self.window.rootViewController=[[VCRoog alloc]init];
[self.window makeKeyAndVisible];
return YES;
}
执行结果事件响应顺序：
