思路：
全选：在模型中 写入参数 记录cell 按钮点击状态 在创建cell 时，根据模型设置 按钮点击状态，点击全选时 遍历数据源，将所有模型的 点击状态做相应更改 并且 刷新Tableview

      选中：当每个 按钮都点击了 全选按钮也应该变为选中状态，否则非选中，遍历数据源模型，如果 按钮状态  = YES 则将 全选按钮设置为 YES， 如果有一个是No，则将 全选按钮设置为 NO 并break 跳出循环，不在执行；

      总金额： 在模型中 设置 商品单价（price） 和 购买数量 （number），点击cell 上的 按钮，或者 点击全选，遍历数据源 如果按钮是选中状态 总金额 = 模型中的 price * number 一直累计加 你= n+1 这种，最后 得出 总金额

pragma mark - 全选

• (void)setupCheckAllButton{

  UIButton * checkAllButton = [[UIButton alloc] init];
  checkAllButton.translatesAutoresizingMaskIntoConstraints = NO;
  [_settleAccountsView addSubview:checkAllButton];
  [checkAllButton mas_makeConstraints:^(MASConstraintMaker *make) {
  make.leftMargin.mas_equalTo(8);
  make.centerY.mas_equalTo(_settleAccountsView);

  }];

  [checkAllButton setTitle:@"全选" forState:UIControlStateNormal];
  [checkAllButton setTitleColor:[UIColor colorWithHexString:@"#333333"] forState:UIControlStateNormal];
  [checkAllButton setTitleEdgeInsets:UIEdgeInsetsMake(0, 0, 0, -4)];
  [checkAllButton setImage:[UIImage imageNamed:@"l9_4_com_list_radio_s"] forState:UIControlStateSelected];
  [checkAllButton setImage:[UIImage imageNamed:@"l9_4_com_list_radio_n"] forState:UIControlStateNormal];
  [checkAllButton addTarget:self action:@selector(checkAllButtonClick:) forControlEvents:UIControlEventTouchUpInside];
  self.checkAllButton = checkAllButton;
  }

//全选 按钮点击

• (void)checkAllButtonClick:(UIButton *)sender{

  double total = 0.0;
  NSLog(@"全选按钮点击");
  if (sender.isSelected) {

    sender.selected = NO;
    for (RSStoreShoppingCartModel * model in _dataSource) {
        
        [model setValue:@"NO" forKey:@"chooseButtonSelected"];
        [self changePrice:@"0.00"];
    }
  

  }else{

    sender.selected = YES;
    
    for (RSStoreShoppingCartModel * model in _dataSource) {
        
        [model setValue:@"YES" forKey:@"chooseButtonSelected"];
  
    }
    
    [self workoutTotal:total];
  

  }

  [self.tableViewPlain reloadData];

}

pragma mark - 总计

• (void)setupTotalLabel{

  UILabel * totalLabel = [[UILabel alloc] init];
  totalLabel.translatesAutoresizingMaskIntoConstraints = NO;
  [_settleAccountsView addSubview:totalLabel];
  [totalLabel mas_makeConstraints:^(MASConstraintMaker *make) {
  make.left.equalTo(_checkAllButton.mas_right).mas_equalTo(24);
  make.centerY.mas_equalTo(_settleAccountsView);
  }];
  self.totalLabel = totalLabel;

  [self changePrice:@"0.00"];

}

pragma mark - 设置 总计 金额

• (void)changePrice:(NSString *)total{

  NSMutableAttributedString * title = [[NSMutableAttributedString alloc] initWithString:@"总计:"];
  NSDictionary * titleAttributes = @{NSFontAttributeName : [UIFont jk_systemFontOfPxSize:30],NSForegroundColorAttributeName : [UIColor colorWithHexString:@"#333333"]};
  [title setAttributes:titleAttributes range:NSMakeRange(0, title.length)];

  NSMutableAttributedString * price = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"￥%@",total]];
  NSDictionary * priceattributes = @{NSFontAttributeName : [UIFont jk_systemFontOfPxSize:30],NSForegroundColorAttributeName : [UIColor colorWithHexString:@"#FF6468"]};
  [price setAttributes:priceattributes range:NSMakeRange(0, price.length)];
  [title appendAttributedString:price];
  _totalLabel.attributedText = title;

}

pragma mark - 算出 总金额

• (void)workoutTotal:(double)total{

  //遍历数据源 如果是选中状态 将模型中的 单价 * 数量 算出 总价
  for(RSStoreShoppingCartModel * shoppingCartModel in _dataSource) {
  if ([shoppingCartModel.chooseButtonSelected isEqualToString:@"YES"] ) {
  total = total + [shoppingCartModel.commodityPrice doubleValue] * [shoppingCartModel.purchaseQuantity intValue] ;
  NSLog(@" 模型中 商品价格：%f",[shoppingCartModel.commodityPrice doubleValue]);
  NSLog(@" 模型中 商品数量：%d",[shoppingCartModel.purchaseQuantity intValue] );
  NSLog(@"总计： %f",total);
  }

       [self changePrice:[NSString stringWithFormat:@"%0.2f",total]];
  

  }

}

pragma mark - 全选状态

• (void)setupCheckAllButtonState{

  //遍历数据源 如果每个Cell 都是选中的，那么全选也应该为选中
  for (RSStoreShoppingCartModel * shoppingCartModel in _dataSource) {

    if ([shoppingCartModel.chooseButtonSelected isEqualToString:@"YES"] ) {
        
        _checkAllButton.selected = YES;
    }else{
        
        _checkAllButton.selected = NO;
        break ;
        
    }
  

  }

}

pragma mark - TableView 代理 数据源

• (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

  RSShoppingCartTableViewCell * shoppingCartCell = [tableView dequeueReusableCellWithIdentifier:shoppingCartTabCellIdentifier];
  if (shoppingCartCell == nil) {
  shoppingCartCell = [[RSShoppingCartTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:shoppingCartTabCellIdentifier];
  }

  RSStoreShoppingCartModel * model = _dataSource[indexPath.row];
  __block double total = 0.0;
  shoppingCartCell.isSelectedBlock = ^(BOOL isSelected) {

    model.chooseButtonSelected = isSelected ? @"YES" : @"NO";
    
    [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:[NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section], nil] withRowAnimation:UITableViewRowAnimationNone];
    //设置全选状态
    [self setupCheckAllButtonState];
    //算出总金额
    [self workoutTotal:total];
  

  };

shoppingCartCell.changeNumberBlock = ^(NSString *number) {
  
    model.purchaseQuantity = number;
    
    [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:[NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section], nil] withRowAnimation:UITableViewRowAnimationNone];
    
};



shoppingCartCell.shoppingCartModel = model;

NSLog(@"模型数量  : %@",model.purchaseQuantity);

return shoppingCartCell;

}