private static DateTime SwitchToUtcTime(DateTime value, UnspecifiedDateTimeHandling dateTimeHandling)
{
switch (value.Kind)
{
case DateTimeKind.Unspecified:
if (dateTimeHandling == UnspecifiedDateTimeHandling.AssumeUtc)
{
return(new DateTime(value.Ticks, DateTimeKind.Utc));
}
else
{
return(new DateTime(value.Ticks, DateTimeKind.Local).ToUniversalTime());
}
case DateTimeKind.Utc:
return(value);
case DateTimeKind.Local:
return(value.ToUniversalTime());
}
return(value);
}
public static DateTime EnsureDateTime(DateTime value, TimeZoneInfo timeZone, DateTimeHandling dateTimeHandling, UnspecifiedDateTimeHandling unspecifiedDateTimeHandling)
{
if (dateTimeHandling == DateTimeHandling.Utc)
{
if (timeZone == null)
{
return(SwitchToUtcTime(value, unspecifiedDateTimeHandling));
}
return(SwitchToUtcTime(value, timeZone, unspecifiedDateTimeHandling));
}
else if (dateTimeHandling == DateTimeHandling.Local)
{
if (timeZone == null)
{
return(SwitchToLocalTime(value, unspecifiedDateTimeHandling));
}
return(SwitchToLocalTime(value, timeZone, unspecifiedDateTimeHandling));
}
else if (dateTimeHandling == DateTimeHandling.Current)
{
if (value.Kind == DateTimeKind.Utc)
{
return(EnsureDateTime(value, timeZone, DateTimeHandling.Utc, unspecifiedDateTimeHandling));
}
else if (value.Kind == DateTimeKind.Local)
{
return(EnsureDateTime(value, timeZone, DateTimeHandling.Local, unspecifiedDateTimeHandling));
}
else
{
if (unspecifiedDateTimeHandling == UnspecifiedDateTimeHandling.AssumeUtc)
{
return(EnsureDateTime(value, timeZone, DateTimeHandling.Utc, unspecifiedDateTimeHandling));
}
else if (unspecifiedDateTimeHandling == UnspecifiedDateTimeHandling.AssumeLocal)
{
return(EnsureDateTime(value, timeZone, DateTimeHandling.Local, unspecifiedDateTimeHandling));
}
else
{
ThrowUnsupportedOption(unspecifiedDateTimeHandling.ToString());
return(value);
}
}
}
else
{
ThrowUnsupportedOption(dateTimeHandling.ToString());
return(value);
}
}
private static DateTime SwitchToLocalTime(DateTime value, TimeZoneInfo timeZone, UnspecifiedDateTimeHandling dateTimeHandling)
{
switch (value.Kind)
{
case DateTimeKind.Unspecified:
if (dateTimeHandling == UnspecifiedDateTimeHandling.AssumeLocal)
{
return(string.Equals(timeZone.Id, TimeZoneInfo.Local.Id, StringComparison.Ordinal) ? new DateTime(value.Ticks, DateTimeKind.Local) : value);
}
else
{
return(TimeZoneInfo.ConvertTimeFromUtc(new DateTime(value.Ticks, DateTimeKind.Utc), timeZone));
}
case DateTimeKind.Utc:
return(TimeZoneInfo.ConvertTimeFromUtc(value, timeZone));
case DateTimeKind.Local:
return(TimeZoneInfo.ConvertTime(value, timeZone));
}
return(value);
}
public static DateTime EnsureDateTime(DateTime value, DateTimeHandling dateTimeHandling, UnspecifiedDateTimeHandling unspecifiedDateTimeHandling)
{
return(EnsureDateTime(value, null, dateTimeHandling, unspecifiedDateTimeHandling));
}
