C#.NET 日期操作类

 

代码

   
     

    
      
    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;

    
      using
    
       System.Runtime.InteropServices;


    
      namespace
    
       Pub.Class
{
 
    
      ///
    
       
    
      <summary>
    
      
 
    
      ///
    
       日期操作类
 
    
      ///
    
       
    
      </summary>
    
      

    
       
    
      public
    
       
    
      class
    
       Date
 {

 
    
      #region
    
       ExactTimeSpan
    
      
 
    
      ///
    
       
    
      <summary>
    
      
 
    
      ///
    
       精确的时间差
 
    
      ///
    
       
    
      </summary>
    
      
 
    
      ///
    
       
    
      <example>
    
      
 
    
      ///
    
       
    
      <code>
    
      
 
    
      ///
    
       context.items["beginrequesttickcount"]=a.gettickcount();
 
    
      ///
    
       代码段
 
    
      ///
    
       new TimeSpan(A.GetTickCount()-(long)Context.Items["BeginRequestTickCount"]).TotalMilliseconds
 
    
      ///
    
       
    
      </code>
    
      
 
    
      ///
    
       
    
      </example>
    
      

    
       
    
      public
    
       
    
      class
    
       ExactTimeSpan { 
 [DllImport(
    
      "
    
      kernel32.dll
    
      "
    
      )]
 
    
      static
    
       
    
      extern
    
       
    
      bool
    
       QueryPerformanceCounter([In, Out] 
    
      ref
    
       
    
      long
    
       lpPerformanceCount);
 [DllImport(
    
      "
    
      kernel32.dll
    
      "
    
      )]
 
    
      static
    
       
    
      extern
    
       
    
      bool
    
       QueryPerformanceFrequency([In, Out] 
    
      ref
    
       
    
      long
    
       lpFrequency);
 
    
      static
    
       
    
      long
    
       _f 
    
      =
    
       
    
      0
    
      ;
 
    
      ///
    
       
    
      <summary>
    
      
 
    
      ///
    
       来纪录程序开始时的TickCount
 
    
      ///
    
       
    
      </summary>
    
      
 
    
      ///
    
       
    
      <returns>
    
      TickCount
    
      </returns>
    
      

    
       
    
      static
    
       
    
      public
    
       
    
      long
    
       GetTickCount() {
 
    
      long
    
       f 
    
      =
    
       _f;
 
    
      if
    
       (f 
    
      ==
    
       
    
      0
    
      )
 
    
      if
    
       (QueryPerformanceFrequency(
    
      ref
    
       f)) _f 
    
      =
    
       f; 
    
      else
    
       _f 
    
      =
    
       
    
      -
    
      1
    
      ;

 
    
      if
    
       (f 
    
      ==
    
       
    
      -
    
      1
    
      ) 
    
      return
    
       Environment.TickCount 
    
      *
    
       
    
      10000
    
      ;
 
    
      long
    
       c 
    
      =
    
       
    
      0
    
      ;
 QueryPerformanceCounter(
    
      ref
    
       c);
 
    
      return
    
       (
    
      long
    
      )(((
    
      double
    
      )c) 
    
      *
    
       
    
      1000
    
       
    
      *
    
       
    
      10000
    
       
    
      /
    
       ((
    
      double
    
      )f));
 }

 
    
      static
    
       
    
      long
    
       _tc 
    
      =
    
       
    
      0
    
      ;
    
      //
    
      GetTickCount()为0时的DateTime.Ticks值
    
      

    
      
 
    
      ///
    
       
    
      <summary>
    
      
 
    
      ///
    
       这个返回的不是真正的精确时间，但时间与时间的差是精确的。
 
    
      ///
    
       GetExactNow与DateTime.Now的偏差比DateTime.Now的精度还要小
 
    
      ///
    
       
    
      </summary>
    
      
 
    
      ///
    
       
    
      <returns>
    
      时间与时间差
    
      </returns>
    
      

    
       
    
      static
    
       
    
      public
    
       DateTime GetExactNow() {
 
    
      if
    
       (_tc 
    
      ==
    
       
    
      0
    
      ) {
 
    
      long
    
       tc 
    
      =
    
       GetTickCount();
 DateTime dt 
    
      =
    
       DateTime.Now;
 _tc 
    
      =
    
       dt.Ticks 
    
      -
    
       tc;
 
    
      return
    
       dt;
 }
 
    
      return
    
       
    
      new
    
       DateTime(_tc 
    
      +
    
       GetTickCount());
 }
 }
 
    
      #endregion
    
      

 }
}