iOS设计模式 - 外观

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

https://github.com/YouXianMing/iOS-Design-Patterns

//
//  ShapeMaker.h
//  FacadePattern
//
//  Created by YouXianMing on 15/7/28.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

#import <Foundation/Foundation.h>
#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 <Foundation/Foundation.h>

@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