.net - 如何将 Integer8 值转换为 DateTime？

Question

如何将 Integer8 类型的值转换为 DateTime 类型的值？特别是，我试图以人类可读的形式获取 accountExpires Active Directory User 属性。 SearchResult.GetDirectoryEntry.Properties("accountExpires") 返回值“9223372036854775807”。

Answer 1

来自 http://www.dotnet247.com/247reference/msgs/19/96138.aspx

An "Integer8" in AD is an object holding two 32 bit properties, called LowPart and HighPArt. Such a property is returned as an generic RCW (__ComObject), what you need to do is unwrap the underlying object or just cast it to a LargInteger COM type. After that you have to combine both properties into a long (64 Bit), if the value represents a date you have to translate the format from FileTime to DateTime.

Following shows how to retrieve "lastLogon" date property. !!! Set a reference to the activeds.tlb, or create an interop library using tlbimp.exe !!!!

     // Use a cast ...
     li = pcoll["lastLogon"].Value as LargeInteger;
     // Or use CreateWrapperOfType
     // li = (LargeIntegerClass)Marshal.CreateWrapperOfType(pcoll["lastLogon"].Value,
 typeof(LargeIntegerClass));
     // Convert to a long
     long date = (((long)(li.HighPart) << 32) + (long) li.LowPart);
     // convert date from FileTime format to DateTime
     string dt = DateTime.FromFileTime(date).ToString();