小编Dav*_*veK的帖子

我目前有以下工作代码.然而,这是非常缓慢的.我知道将所有权作为查询而不是列表传递可能会简化并加快速度,但由于各种原因,这是不可能的.

如何在不创建新列表的情况下更新现有的馆藏列表？其他改进代码的建议？

internal List<DailyHoldingItem> TransformHoldingItemsToCurrency(List<DailyHoldingItem> holdings,string toCurrency)
        {
        //TODO - how to do this calculation in place, without creating a new list?
        var query = (from holding in holdings
                     from fxRateHolding in amdw.FXRates
                     from fxRateToCur in amdw.FXRates
                     where
                     fxRateHolding.BaseCurrency == holding.Currency &&
                     fxRateToCur.BaseCurrency == toCurrency &&
                     fxRateHolding.ValueDate == holding.Date &&
                     fxRateToCur.ValueDate == holding.Date
                     select new { holding, fxRateHolding, fxRateToCur });

        return query.Select(dhi =>
        {
            decimal factor = dhi.fxRateToCur.Value / dhi.fxRateHolding.Value;
            dhi.holding.MarketValue *= factor;
            dhi.holding.Fee *= factor;
            dhi.holding.Remuneration *= factor;
            return …