Question

我有一个WPF C＃应用程序，它通过SQL-LINQ连接访问数据并将其放在Datagrid上。我添加了一个Running Pips列，并一直试图找出如何正确填充此列。我通过搜索网络找到了几种方法，但这些方法都不适合我的特定设置。大部分时间我都是无休止的循环。我希望Running Pips列是累积的，并且计算的顺序从最早的'Close Time'开始。

Close Time   Profit    Running Profit
 10.09.11     $10          $10 
 10.10.11     $20          $30 
 10.11.11     $15          $45

以下是代码摘要。我希望有人可以建议如何修复此代码以及帮助我实现此目的所需的任何相关信息：

public void RefreshClose() {
    if (CloseTradeCollection == null) return;
    var i = 0;

    if (StaticTool.SelectedAccount == null) {
        ExistCloseTrade = false;
        CloseTradeCollection.Clear();
        return;
    }

    Account = StaticTool.SelectedAccount;

    foreach (var trade in GetClosedTradesFromDb()) {
        if (CloseTradeCollection.Count <= i) {
            ExistCloseTrade = true;
            var tradeDetails = new Trade {
                Id = trade.id,
                Ticket = trade.ticket,
                OpenTime = trade.opentime,
                CloseTime = trade.closetime,
                Symbol = trade.symbol,
                OpenPrice = trade.openprice,
                ClosePrice = trade.closeprice,
                Profit = trade.profit,
                Comment = trade.comment.Trim(),
            };

            tradeDetails.History = tradeDetails.CloseTime - tradeDetails.OpenTime;
            CloseTradeCollection.Add(tradeDetails);
        }

        else {
            var tradeDetails = CloseTradeCollection[i];
            tradeDetails.Id = trade.id;
            tradeDetails.Ticket = trade.ticket;
            tradeDetails.OpenTime = trade.opentime;
            tradeDetails.CloseTime = trade.closetime;
            tradeDetails.Symbol = trade.symbol;
            tradeDetails.OpenPrice = trade.openprice;
            tradeDetails.ClosePrice = trade.closeprice;
            tradeDetails.Profit = trade.profit;
            tradeDetails.Comment = trade.comment.Trim();
            tradeDetails.History = DateTime.Now - tradeDetails.OpenTime;

            //tradeDetails.RunningProfit = ????????

        }

        i++;
    }
}

Answer 1

您可以创建一个局部变量来跟踪运行利润，利用赋值操作返回所分配值的事实。

tradeDetails.RunningProfit = (runningProfit = runningProfit + trade.profit);

Answer 2

这是一个大致的想法 - 您应该能够根据自己的需要采用它：

class Trade {
    public DateTime CloseTime { get; set; }
    public decimal Profit { get; set; }
}

class TradeWithRunningProfit : Trade {
    public decimal RunningProfit { get; set; }
}

class Program {

    static IEnumerable<TradeWithRunningProfit> GetRunningProfits(IEnumerable<Trade> rows) {

        decimal running_profit = 0;

        return
            from row in rows
            select new TradeWithRunningProfit {
                CloseTime = row.CloseTime,
                Profit = row.Profit,
                RunningProfit = (running_profit += row.Profit)
            };

    }

    static void Main(string[] args) {

        var rows = new[] {
            new Trade { CloseTime = new DateTime(11,10,09), Profit = 10},
            new Trade { CloseTime = new DateTime(11,10,10), Profit = 20},
            new Trade { CloseTime = new DateTime(11,10,11), Profit = 15},
        };

        foreach (var row_with_running_profit in GetRunningProfits(rows)) {
            Console.WriteLine(
                "{0}\t{1}\t{2}",
                row_with_running_profit.CloseTime,
                row_with_running_profit.Profit,
                row_with_running_profit.RunningProfit
            );
        }

    }

}

使用LINQ to SQL计算运行总计

2 个答案: