如何比较C＃中hh：mm：ss格式的日期时间？ [英] How to compare time from datetime in hh:mm:ss format in C# ?

问题描述

大家好，

i有视觉工作室winform c＃

i希望比较日期时间的hh：mm格式在特定范围内的时间。

但是它不能正常工作


我的源代码中的
范围是[start_time，End_time]。



换句话说，从日期时间我只想提取时间

例如：2015-04-05 2:14:00只提取2:14:00

并将其与具有相同格式的特定范围进行比较。



我尝试了什么：

hi all,
i have visual studio winform c#
i want to compare the time from DateTime in hh:mm format in a specific range.
but it is not working

in my source code below the range is [start_time ,End_time].

In other words, from the datetime i want to extract the time only
e.g: 2015-04-05 2:14:00 extract only 2:14:00
and compare it with a specific range that has also the same format.

What I have tried:

DateTime current_time = DateTime.Now;
var End_time=current_time.ToString("hh:mm"); //End_time
var start_time = current_time.AddHours(-2).ToString("hh:mm");//start_time 

DataTable dchild= new DataTable();
string query=SELECT DATE_FORMAT( date_created,  '%h:%i:%s' ) time_created from table ;
adap_child = new MySqlDataAdapter(query, strconnection);
            adap_child.Fill(dchild);   
  
foreach (DataRow items in dchild.Rows)
{
  var  date_to_be_compared = (int)items["time_created"];
if(time_to_compared >=start_time && date_to_be_compared<=End_time)//error appears here
   {
     //code
    }
else
{
//code
}

}

推荐答案

将从 SELECT 返回的内容更改为 DATETIME 实际存储在数据库中的值。然后得到 TimeOfDay 部分和在其他地方使用它！



尝试像：

Change what you get back from the SELECT to be the DATETIME value that is actually stored in the DB. Then get the TimeOfDay part and use that everywhere else!

Try something like:

DateTime current_time = DateTime.Now;
TimeSpan End_time=current_time.TimeOfDay; //End_time
TimeSpan start_time = End_time.SubtractHours(-2);//start_time 

DataTable dchild= new DataTable();
string query = "SELECT date_created FROM table";
adap_child = new MySqlDataAdapter(query, strconnection);
adap_child.Fill(dchild);   
  
foreach (DataRow items in dchild.Rows)
{
  TimeSpan time_to_be_compared = ((DateTime)items["date_created"]).TimeOfDay;
  if (start_time <= time_to_be_compared && time_to_be_compared <= End_time)
  {
     //code
  }
  else
  {
     //code
  }
}

你可以得到时间作为TimeSpan对象

You can get the time as a TimeSpan object

DateTime current_time = DateTime.Now;
DateTime date_to_be_compared = DateTime.ParseExact("12 Aug 2014 13:45:22", "dd MMM yyyy HH:mm:ss", System.Globalization.CultureInfo.CurrentCulture);

TimeSpan ts_current = current_time.TimeOfDay;
TimeSpan ts_compare = date_to_be_compared.TimeOfDay;

if (ts_current > ts_compare)
{
    System.Diagnostics.Debug.WriteLine("Current time is after compare time");
}
else
{
    System.Diagnostics.Debug.WriteLine("Current time is not after compare time");
}

这篇关于如何比较C＃中hh：mm：ss格式的日期时间？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！