金融app相对普通app而言，出于安全考虑，其安全校验方式比较多，以某些银行app为例，手机号登录成功后，会增加指纹、手势、OCR人脸等验证！这些安全项的校验，会根据用户的风险等级有不同的校验优先级，例如A客户的校验顺序是先指纹->手势->OCR,B客户的校验顺序可能是先手势->OCR，其验证顺序不固定，故此处用责任链的模式来设计更为合理：
demo地址：https://download.csdn.net/download/denggun12345/88104411?spm=1001.2014.3001.5503
//基类BusinessObject
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
@class BusinessObject;
typedef void (^CompletionBlock)(BOOL handled);
typedef void (^ResultBlock)(BusinessObject *handler, BOOL handled);
@interface BusinessObject : NSObject
@property (nonatomic ,strong) UILabel *LB;
//下一个响应者
@property (nonatomic ,strong) BusinessObject *nextBusiness;
//响应者的处理方法
-(void)handle:(ResultBlock)result;
//各个业务在该方法当中做时机业务处理
-(void)handleBusiness:(CompletionBlock)completion;
@end
NS_ASSUME_NONNULL_END
#import "BusinessObject.h"
@implementation BusinessObject
//责任链入口方法
-(void)handle:(ResultBlock)result{
CompletionBlock completion = ^(BOOL handled){
//当前业务处理掉了，上抛结果
if(handled){
result(self,handled);
}else{
//沿着责任链，指派给下一个业务处理
if (self.nextBusiness){
**self**.nextBusiness handle:result\]; }**else**{ //没有业务处理，上抛 result(**nil** ,**NO**); } } }; //当前业务进行处理 \[**self** handleBusiness:completion\]; } -(**void**)handleBusiness:(CompletionBlock)completion{ //业务逻辑处理 //如不网络请求、本地照片查询等 } **@end** 模拟业务类，即继承基类的类，用来模拟指纹、手势、ocr的业务类 #import "BusinessObjectA.h" **@implementation** BusinessObjectA -(**void**)handleBusiness:(CompletionBlock)completion{ NSLog(@"BusinessObjectA"); **if** (\[**self**.LB.text isEqualToString:@"0"\]) { completion(**YES**); }**else**{ completion(**NO**); } } **@end** #import "BusinessObjectB.h" **@implementation** BusinessObjectB -(**void**)handleBusiness:(CompletionBlock)completion{ NSLog(@"BusinessObjectB"); **if** (\[**self**.LB.text isEqualToString:@"0"\]) { completion(**YES**); }**else**{ completion(**NO**); } } **@end** #import "BusinessObjectC.h" **@implementation** BusinessObjectC -(**void**)handleBusiness:(CompletionBlock)completion{ NSLog(@"BusinessObjectC"); **if** (\[**self**.LB.text isEqualToString:@"0"\]) { completion(**YES**); }**else**{ completion(**NO**); } } **@end** //模拟处理逻辑优先级 #import "ViewController.h" #import "BusinessObjectA.h" #import "BusinessObjectB.h" #import "BusinessObjectC.h" **@interface** ViewController () //背景变红色 **@property** (**nonatomic** ,**assign** ) **BOOL** isOuShu; **@property** (**weak** , **nonatomic** ) **IBOutlet** UILabel \*LBOne; **@property** (**weak** , **nonatomic** ) **IBOutlet** UILabel \*LBTwo; **@property** (**weak** , **nonatomic** ) **IBOutlet** UILabel \*LBThree; **@property** (**nonatomic** ,**strong**) NSArray \*testArray; **@property** (**weak** , **nonatomic** ) **IBOutlet** UIButton \*testBtn; **@end** **@implementation** ViewController -(NSArray \*)testArray{ **if**(!_testArray){ _testArray = @\[@1,@2,@3\]; } **return** _testArray; } - (**void**)viewDidLoad { \[**super** viewDidLoad\]; // Do any additional setup after loading the view.} - (**IBAction** )ClickAction:(**id**)sender { **int** x = arc4random() % 3;//0 1 2 模拟责任链中密码、手势、指纹的优先级 **self**.LBOne.text = \[NSString stringWithFormat:@"%d",x\]; **self**.LBTwo.text = \[NSString stringWithFormat:@"%d",x-1\]; **self**.LBThree.text = \[NSString stringWithFormat:@"%d",x-2\]; //开始责任链 //a指纹 BusinessObjectA \*objA = \[BusinessObjectA new\]; objA.LB = **self**.LBOne; \[objA handle:\^(BusinessObject \* **_Nonnull** handler, **BOOL** handled) { **if**(handled){ NSLog(@"a_yes_handler_test:%@",handler.LB.text); \[**self**.testBtn setTitle:@"LBOne" forState:UIControlStateNormal\]; }**else**{ NSLog(@"a_no_handler_test:%@",handler.LB.text); } }\]; //b手势 BusinessObjectB \*objB = \[BusinessObjectB new\]; objB.LB = **self**.LBTwo; objA.nextBusiness = objB; \[objB handle:\^(BusinessObject \* **_Nonnull** handler, **BOOL** handled) { **if**(handled){ NSLog(@"b_yes_handler_test:%@",handler.LB.text); \[**self**.testBtn setTitle:@"LBTwo" forState:UIControlStateNormal\]; }**else**{ NSLog(@"b_no_handler_test:%@",handler.LB.text); } }\]; //cOCR BusinessObjectC \*objC = \[BusinessObjectC new\]; objC.LB = **self**.LBThree; objB.nextBusiness = objC; \[objC handle:\^(BusinessObject \* **_Nonnull** handler, **BOOL** handled) { **if**(handled){ \[**self**.testBtn setTitle:@"LBThree" forState:UIControlStateNormal\]; NSLog(@"c_yes_handler_test:%@",handler.LB.text); }**else**{ NSLog(@"c_no_handler_test:%@",handler.LB.text); } }\]; } **@end**