iOS App设计模式开发中策略模式的实现示例

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

@interface CashContext :NSObject{
@private CashSuper *cs;
}
-(CashContext*)MyInit:(int)Types;
-(void)SetCashSuper:(CashSuper*)cashSuper;
-(double)GetResult:(double)money;
@end

#import "CashContext.h"
#import "CashNormal.h"
#import "CashRebate.h"
#import "CashReturn.h"

@implementation CashContext

-(CashContext*)MyInit:(int)Types{
    int myTypes;
    myTypes = Types;
    switch(myTypes) {
        case 1:
            [self SetCashSuper:[[CashNormalalloc]init]];
            break;
        case 2:
            [self SetCashSuper:[[CashReturnalloc]MyInit:300 And:100]];
            break;
        case 3:
            [self SetCashSuper:[[CashRebatealloc]MyInit:0.8]];
            break;
        default:
            break;
    }
    return self;
}
-(void)SetCashSuper:(CashSuper*)cashSuper{
    cs = cashSuper;
}
-(double)GetResult:(double)money{
    return [cs AcceptCash:money];
}

@end

#import <Foundation/Foundation.h>

@interface CashSuper :NSObject
-(double)AcceptCash:(double)money;
@end

#import"CashSuper.h"

@implementation CashSuper

-(double)AcceptCash:(double)money{
    return -1.0; //这里返回 -1.0无任何意义，只是为了定义此方法
}

@end

#import"CashSuper.h"

@interface CashNormal :CashSuper
@end

#import"CashNormal.h"

-(double)AcceptCash:(double)money{
    return money;
}

@end

#import"CashSuper.h"

@interface CashRebate :CashSuper{
@private double moneyRebate;
}
@property double moneyRebate;
-(CashRebate*)MyInit:(double)moneyRebates;
@end

#import"CashRebate.h"

@implementation CashRebate
@synthesize moneyRebate;

-(CashRebate*)MyInit:(double)moneyRebates{
    [self setMoneyRebate:moneyRebates];
    return self;
}
-(double)AcceptCash:(double)money{
    return moneyRebate*money;
}

@end

#import "CashSuper.h"

@interface CashReturn :CashSuper{
@private double moneyCondition;
@private double moneyReturn;
}
@property double moneyCondition;
@property double moneyReturn;
-(CashReturn*)MyInit:(double)moneyConditions And:(double)moneyReturns;
@end

#import "CashReturn.h"

@implementation CashReturn
@synthesize moneyReturn;
@synthesize moneyCondition;

-(CashReturn*)MyInit:(double)moneyConditions  And:(double)moneyReturns{
    [self setMoneyReturn:moneyReturns];
    [self setMoneyCondition:moneyConditions];
    return self;
}
-(double)AcceptCash:(double)money{
    double result;
    result = money;
    @try{
        if(money >=moneyCondition){
            result = money - (money /moneyCondition)*moneyReturn;
        }
    }
    @catch(NSException *exception) {
        NSLog(@"Oh!Man!!CashReturn has something wrong!");
    }
    @finally{
        return result;
    }
}

@end

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

int main (int argc, const char  *argv[])
{
    @autoreleasepool {
        CashContext *cc = [[CashContext alloc]MyInit:3];
        double total;
        total = [cc GetResult:400];
        NSLog(@"Total Money 400,the resual is %f", total);
    }
    return 0;
}