iOS设计模式 - 外观

原理图

说明

1. 当客服端需要使用一个复杂的子系统(子系统之间关系错综复杂),但又不想和他们扯上关系时,我们需要单独的写出一个类来与子系统交互,隔离客户端与子系统之间的联系,客户端只与这个单独写出来的类交互

2. 外观模式实质为为系统中的一组接口提供一个统一的接口,外观定义了一个高层接口,让子系统易于使用

源码

////  ShapeMaker.h//  FacadePattern////  Created by YouXianMing on 15/7/28.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import 
    
     #import "Shape.h"#import "Circle.h"#import "Rectangle.h"#import "Square.h"@interface ShapeMaker : NSObject+ (void)drawCircleAndRectangle;+ (void)drawCircleAndSquare;+ (void)drawAll;@end
    

////  ShapeMaker.m//  FacadePattern////  Created by YouXianMing on 15/7/28.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import "ShapeMaker.h"@implementation ShapeMaker+ (void)drawCircleAndRectangle {    Shape *circle    = [Circle new];    Shape *rectangle = [Rectangle new];        [circle draw];    [rectangle draw];    NSLog(@"\n");}+ (void)drawCircleAndSquare {    Shape *circle    = [Circle new];    Shape *square    = [Square new];        [circle draw];    [square draw];    NSLog(@"\n");}+ (void)drawAll {    Shape *circle    = [Circle new];    Shape *rectangle = [Rectangle new];    Shape *square    = [Square new];        [circle draw];    [rectangle draw];    [square draw];    NSLog(@"\n");}@end

////  Shape.h//  FacadePattern////  Created by YouXianMing on 15/7/28.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import 
    
     @interface Shape : NSObject/** *  绘制 */- (void)draw;@end
    

////  Shape.m//  FacadePattern////  Created by YouXianMing on 15/7/28.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import "Shape.h"@implementation Shape- (void)draw {    // 由子类重写}@end

分析

详细对比示意图