IMG_4721.PNG

• 創(chuàng)建一個(gè)繼承于tableViewCell的子類(lèi)WineCell，在.h創(chuàng)建一個(gè)代理，在點(diǎn)擊加號(hào)或者減號(hào)的時(shí)候，通知代理來(lái)實(shí)時(shí)改變總價(jià)，

@class Wine ,WineCell;
@protocol WineCellDelegate <NSObject>
@optional
- (void)wineCellDidClickPlusButton:(WineCell *)cell;
- (void)wineCellDidClickMinusButton:(WineCell *)cell;

@end

@interface WineCell : UITableViewCell
/** 模型*/
@property (nonatomic, strong) Wine *wine;

/** 代理屬性*/
@property (nonatomic, weak) id<WineCellDelegate> delegate;

@end

• .m中

- (IBAction)plusButtonClick {
    // 1.修改模型
    self.wine.count ++ ;
    // 2.修改界面
    self.countLabel.text = [NSString stringWithFormat:@"%d",self.wine.count];
    // 3.減號(hào)按鈕能點(diǎn)擊
    self.minusButton.enabled = YES;
    // 4.通知代理(調(diào)用代理的方法)
    if ([self.delegate respondsToSelector:@selector(wineCellDidClickPlusButton:)]) {
        [self.delegate wineCellDidClickPlusButton:self];
    }
}
/**
 *  減號(hào)點(diǎn)擊
 */
- (IBAction)minusButtonClick {
    // 1.修改模型
    self.wine.count -- ;
    // 2.修改界面
    self.countLabel.text = [NSString stringWithFormat:@"%d",self.wine.count];
    // 3.控制減號(hào)按鈕是否能點(diǎn)擊
    if (self.wine.count == 0) {
        self.minusButton.enabled = NO;
    }
    // 4.通知代理(調(diào)用代理的方法)
    if ([self.delegate respondsToSelector:@selector(wineCellDidClickMinusButton:)]) {
        
        [self.delegate wineCellDidClickMinusButton:self];
    }
}

#pragma mark - WineCellDelegate
- (void)wineCellDidClickPlusButton:(WineCell *)cell
{
    // 計(jì)算總價(jià)
    int totalPrice = self.totalPriceLabel.text.intValue + cell.wine.money.intValue;
    // 設(shè)置總價(jià)
    self.totalPriceLabel.text = [NSString stringWithFormat:@"%d",totalPrice];
    // 購(gòu)買(mǎi)按鈕一定能點(diǎn)擊
    self.buyButton.enabled = YES;
    
    // 之前沒(méi)有添加過(guò),才添加
    if (![self.shoppingCar containsObject:cell.wine]) {
        [self.shoppingCar addObject:cell.wine];
    }
}

- (void)wineCellDidClickMinusButton:(WineCell *)cell
{
    // 計(jì)算總價(jià)
    int totalPrice = self.totalPriceLabel.text.intValue - cell.wine.money.intValue;
    // 設(shè)置總價(jià)
    self.totalPriceLabel.text = [NSString stringWithFormat:@"%d",totalPrice];
    // 購(gòu)買(mǎi)按鈕是否能點(diǎn)擊
    self.buyButton.enabled = totalPrice > 0;
    // 移除用戶不需要在買(mǎi)的酒
    if (cell.wine.count == 0) {
        [self.shoppingCar removeObject:cell.wine];
    }
}