VB6 GMTOffset到C＃

Question

我正在尝试将以下代码从VB6转换为C＃。我只是不确定从哪里开始，我想也许是因为我很喜欢VB6并且似乎无法退后一步。

Private Function GMT_OFFSET() As Integer
    '****DECLARE VARIABLES
    Dim dtNow As Date, dtEngland As Date
    Dim dtGMT As SYSTEMTIME
    '****GET SYSTEM TIME INFORMATION
    Call GetSystemTime(dtGMT)
    dtNow = Now
    dtEngland = dtGMT.wYear & "-" & dtGMT.wMonth & "-" & dtGMT.wDay & " " & dtGMT.wHour & ":" & dtGMT.wMinute & ":" & dtGMT.wSecond
    '****RETURN QUARTER HOURS
    GMT_OFFSET = DateDiff("n", dtEngland, dtNow) \ 15
End Function

我知道GetSystemTime是一个Win32 API，显然不想在.NET中使用PInvoke，而是使用.NET Framework中的纯对象。

Answer 1

根据您的代码，您正在寻找以下内容：

        var dtNow = DateTime.Now;
        var dtOffset = (dtNow.ToUniversalTime().Subtract(dtNow)).TotalMinutes / 15;

如果通用时间大于当前系统时间，则可能需要负偏移调整偏移量。

Answer 2

系统时间：

DateTime systemDateTime = DateTime.Now;

但更重要的是，系统运行的偏移量为：

TimeZoneInfo systemTimeZone = TimeZoneInfo.Local;
TimeSpan offset = systemTimeZone.GetUtcOffset();
Int32 offsetMinutes = offset.Hours * 60 + offset.Minutes;

Answer 3

近直接翻译：

//Private Function GMT_OFFSET() As Integer
int GMT_OFFSET()
{
  //'****DECLARE VARIABLES
  //Dim dtNow As Date, dtEngland As Date
  DateTime dtNow, dtEngland;
  //Dim dtGMT As SYSTEMTIME
  //'****GET SYSTEM TIME INFORMATION
  //Call GetSystemTime(dtGMT)
  //dtNow = Now
  //dtEngland = dtGMT.wYear & "-" & dtGMT.wMonth & "-" & dtGMT.wDay & " " & dtGMT.wHour & ":" & dtGMT.wMinute & ":" & dtGMT.wSecond
  dtEngland = DateTime.UtcNow;
  dtNow = dtEngland.ToLocalTime;
  //'****RETURN QUARTER HOURS
  //GMT_OFFSET = DateDiff("n", dtEngland, dtNow) \ 15
  return Convert.ToInt32((dtNow - dtEngland).TotalMinutes) / 15;
//End Function
}

NB VB6 DateDiff(interval,date1,date2)导致基于date2 - date1的间隔，不反之亦然。

但是单行是：

return Convert.ToInt32(TimeZoneInfo.Local.GetUtcOffset(DateTime.UtcNow).TotalMinutes) / 15;