要是否是很懂的話,能夠直接看上一片關於runtime的介紹。git
應用場景1:坑爹的服務器是否是常常返回一些null數據給你,特別是數組還有字典,而後每次你接收到數據進行轉碼再到model以後,調出model的數組的時候,老是要寫上一些判斷,github
[model.array isKindOfClass:[NSArray class]] && model.array.count > 0)
原則上講是這樣寫比較嚴謹,問題是寫出來的代碼很臃腫,本身都很難接受,我懶!不加上去的話,往NSNull調用不存在的方法,直接Crash,又要被扣工資的節奏。。。最佳解決方法:使用swizzleInstanceMethod。代碼直接見Demo:https://github.com/caijunrong/JRExtension.git數組
應用場景2:對於公司原來的一些代碼,想對UIButton的點擊事件作一部分修改,可是若是使用繼承出來的UIBtton來解決的話, 又要改大量的代碼,這時候,使用runtime攔截替換髮送點擊事件的方法能夠迅速解決這個問題,超級給力!服務器
不廢話,直接上代碼ide
// // UIControl+UIControl_XY.h // iOSanimation // // Created by biyabi on 15/9/29. // Copyright © 2015年 caijunrong. All rights reserved. // #import <UIKit/UIKit.h> @interface UIControl (UIControl_XY) @property (nonatomic, assign) NSTimeInterval cjr_acceptEventInterval;// 能夠用這個給重複點擊加間隔 @end
// // UIControl+UIControl_XY.m // iOSanimation // // Created by biyabi on 15/9/29. // Copyright © 2015年 caijunrong. All rights reserved. // #import "UIControl+UIControl_XY.h" #import <objc/runtime.h> @interface UIControl() @property (nonatomic, assign) NSTimeInterval cjr_acceptEventTime; @end @implementation UIControl (UIControl_XY) static const char *UIControl_acceptEventInterval = "UIControl_acceptEventInterval"; static const char *UIControl_acceptEventTime = "UIControl_acceptEventTime"; - (NSTimeInterval )cjr_acceptEventInterval{ return [objc_getAssociatedObject(self, UIControl_acceptEventInterval) doubleValue]; } - (void)setCjr_acceptEventInterval:(NSTimeInterval)cjr_acceptEventInterval{ objc_setAssociatedObject(self, UIControl_acceptEventInterval, @(cjr_acceptEventInterval), OBJC_ASSOCIATION_RETAIN_NONATOMIC); } - (NSTimeInterval )cjr_acceptEventTime{ return [objc_getAssociatedObject(self, UIControl_acceptEventTime) doubleValue]; } - (void)setCjr_acceptEventTime:(NSTimeInterval)cjr_acceptEventTime{ objc_setAssociatedObject(self, UIControl_acceptEventTime, @(cjr_acceptEventTime), OBJC_ASSOCIATION_RETAIN_NONATOMIC); } + (void)load{ //獲取着兩個方法 Method systemMethod = class_getInstanceMethod(self, @selector(sendAction:to:forEvent:)); SEL sysSEL = @selector(sendAction:to:forEvent:); Method myMethod = class_getInstanceMethod(self, @selector(cjr_sendAction:to:forEvent:)); SEL mySEL = @selector(cjr_sendAction:to:forEvent:); //添加方法進去 BOOL didAddMethod = class_addMethod(self, sysSEL, method_getImplementation(myMethod), method_getTypeEncoding(myMethod)); //若是方法已經存在了 if (didAddMethod) { class_replaceMethod(self, mySEL, method_getImplementation(systemMethod), method_getTypeEncoding(systemMethod)); }else{ method_exchangeImplementations(systemMethod, myMethod); } //----------------以上主要是實現兩個方法的互換,load是gcd的只shareinstance,果斷保證執行一次 } - (void)cjr_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event{ if (NSDate.date.timeIntervalSince1970 - self.cjr_acceptEventTime < self.cjr_acceptEventInterval) { return; } if (self.cjr_acceptEventInterval > 0) { self.cjr_acceptEventTime = NSDate.date.timeIntervalSince1970; } [self cjr_sendAction:action to:target forEvent:event]; } @end
@interface ALViewController () @property (nonatomic, strong) UIButton *; @end @implementation AutoLayoutViewController - (void)viewDidLoad { [super viewDidLoad]; self.suggessBtn = [UIButton buttonWithType:UIButtonTypeCustom]; [self.suggessBtn addTarget:self action:@selector(clickWithInterval:) forControlEvents:UIControlEventTouchUpInside]; self.suggessBtn.cjr_acceptEventInterval = 5.0f; } - (void)clickWithInterval:(UIButton *)suButton{ NSLog(@"打印出來--"): }