[英]How to overcome foreach loop for list object dynamically
我在某些條件下交換List對象中的值並更新List Object值。
目前,我正在做的是 - 通過List循環每個對象 - 檢查條件是否為net - 交換值
public static void SwapMinMaxIfNull<T>(this IEnumerable<T> rows, string reportfor)
{
if (reportfor.Equals("Comparison"))
{
var row = rows as IEnumerable<RiskBoardDataToExport>;
try
{
if (rows.Any())
{
var Tests = row.Where(min => min.MinGaitSpeed == null && min.MaxGaitSpeed != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinGaitSpeed = test.MaxGaitSpeed;
test.MaxGaitSpeed = null;
}
}
// again check for next object
Tests = row.Where(min => min.MinTUGTime == null && min.MaxTUGTime != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinTUGTime = test.MaxTUGTime;
test.MaxTUGTime = null;
}
}
// again check for next object
Tests = row.Where(min => min.MinBergScoreSpeed == null && min.MaxBergScoreSpeed != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinBergScoreSpeed = test.MaxBergScoreSpeed;
test.MaxBergScoreSpeed = null;
}
}
//.. for brevity
}
}
}
我能以更好的方式做到嗎? 我知道PropertyInfo即可以檢查屬性名稱和獲取值等,但是,沒有任何提示來完成這項工作。
謝謝
這不完全是你所要求的,但你可以在Where
語句中組合子句,然后在正文中有一些if
語句:
public static void SwapMinMaxIfNull(this IEnumerable<RiskBoardDataToExport> rows,
string reportfor)
{
if (rows = null) return;
if (reportfor.Equals("Comparison", StringComparison.OrdinalIgnoreCase))
{
foreach (var row in rows.Where(r =>
(r.MinGaitSpeed == null && r.MaxGaitSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null)))
{
if (row.MinGaitSpeed == null)
{
row.MinGaitSpeed = row.MaxGaitSpeed;
row.MaxGaitSpeed = null;
}
if (row.MinTUGTime == null)
{
row.MinTUGTime = row.MaxTUGTime;
row.MaxTUGTime = null;
}
if (row.MinBergScoreSpeed == null)
{
row.MinBergScoreSpeed = row.MaxBergScoreSpeed;
row.MaxBergScoreSpeed = null;
}
}
}
}
由於這是一個列表中項目順序無關緊要的操作,您可以通過並行化輕松加快速度(您可以在此處閱讀)。
所以,你應該做的是,以並行的方式處理這個foreach循環,並將它與Rufus L'的優化代碼結合起來,以獲得最快的結果。
var rows = rows.Where(r =>
(r.MinGaitSpeed == null && r.MaxGaitSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null))
Parallel.ForEach(rows, (row) => {
{
if (row.MinGaitSpeed == null)
{
row.MinGaitSpeed = row.MaxGaitSpeed;
row.MaxGaitSpeed = null;
}
if (row.MinTUGTime == null)
{
row.MinTUGTime = row.MaxTUGTime;
row.MaxTUGTime = null;
}
if (row.MinBergScoreSpeed == null)
{
row.MinBergScoreSpeed = row.MaxBergScoreSpeed;
row.MaxBergScoreSpeed = null;
}
}
請注意,這需要System.Threading.Tasks命名空間,這是Parallel
類的位置。
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