C# 处理DateTime算法,取某月第1天及最后一天

 

代码如下所示:

/// <summary>  
/// 取得某月的第一天  
/// </summary>  
/// <param name="datetime">要取得月份第一天的时间</param>  
/// <returns></returns>  
private DateTime FirstDayOfMonth(DateTime datetime)  
{  
    return datetime.AddDays(1 - datetime.Day);  
}  
  
/// <summary>  
/// 取得某月的最后一天  
/// </summary>  
/// <param name="datetime">要取得月份最后一天的时间</param>  
/// <returns></returns>  
private DateTime LastDayOfMonth(DateTime datetime)  
  
    return datetime.AddDays(1 - datetime.Day).AddMonths(1).AddDays(-1);  
}  
  
/// <summary>  
/// 取得上个月第一天  
/// </summary>  
/// <param name="datetime">要取得上个月第一天的当前时间</param>  
/// <returns></returns>  
private DateTime FirstDayOfPreviousMonth(DateTime datetime)  
{  
    return datetime.AddDays(1 - datetime.Day).AddMonths(-1);  
}  
  
/// <summary>  
/// 取得上个月的最后一天  
/// </summary>  
/// <param name="datetime">要取得上个月最后一天的当前时间</param>  
/// <returns></returns>  
private DateTime LastDayOfPrdviousMonth(DateTime datetime)  
{  
    return datetime.AddDays(1 - datetime.Day).AddDays(-1);  
}

 

posted @ 2018-10-23 22:19  DotNet码农  阅读(2795)  评论(0编辑  收藏
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