Re: Time conversion - C# Discussion Boards

2-May-07 2:42

Hi,
I have a problem with the conversion of a string of type "07:30" into a time. I want to take only the time, without the date. I tried
DateTime openTime = DateTime.Now.ToShortTimeString(open);
,where open = "07:30".

Please help me with this problem.

Luc Pattyn2-May-07 3:04

Luc Pattyn

2-May-07 3:04

Hi,

a DateTime always contains date and time.
TimeOfDay gives time since midnight.
Hence:

DateTime dt=DateTime.Parse(myInputString);
TimeSpan time=dt.TimeOfDay;

Luc Pattyn

[My Articles]

Anka_Ame2-May-07 3:11

2-May-07 3:11

But if my string is like this "07:30", what can I do? Because I tried that method and my result is 00:00:00.
D'Oh! | :doh:

Luc Pattyn2-May-07 4:06

Luc Pattyn

2-May-07 4:06

When I run the code snippet

DateTime dt=DateTime.Parse("07:30");
TimeSpan time=dt.TimeOfDay;
log(time.ToString());

I get "07:30:00" as expected.

BTW if you're not satisfied by Parse, there also is DateTime.ParseExact().

Smile | :)

Luc Pattyn

[My Articles]

Malcolm Smart2-May-07 4:38

2-May-07 4:38

Cool. I've always padded it out with current day/month/year. Learn something new everyday here.... Smile | :)

Regards

Angel
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Malcolm Smart2-May-07 3:31

2-May-07 3:31

try

<br />
//get the current date and time<br />
System.DateTime nowTime = System.DateTime.Now;<br />
<br />
//set our time<br />
System.DateTime openTime = System.DateTime.Parse(nowTime .ToShortDateString() + " 07:30:00");<br />
<br />
//get difference<br />
TimeSpan open = nowTime - openTime;<br />
<br />
<br />
if (nowTime > openTime) //we're open<br />
      Console.WriteLine("We've been open for {0:0} minutes", open.TotalMinutes);<br />
else<br />
      Console.WriteLine("We will open in  {0:0} minutes", -open.TotalMinutes);<br />
            <br />

There must be better methods though...?

Regards

Angel
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Anka_Ame2-May-07 3:36

2-May-07 3:36

The problem is that I will take the string from a Xml file and I cant use it like that. I really need help.

Malcolm Smart2-May-07 3:46

2-May-07 3:46

what exactly are you trying to do? can you post more code?

Regards

Angel
*********************************************

Anka_Ame2-May-07 4:21

2-May-07 4:21

I read a Xml file and from it I will have a string, for example the string name is open="07:30".
I tried to read it like this
DateTime oTime = DateTime.Parse(open);
TimeSpan openTime = oTime.TimeOfDay;
where openTime is of type TimeSpan.
But the result is 00:00:00 and it doesnt work.

Malcolm Smart2-May-07 4:35

2-May-07 4:35

You still haven't posted any code....

I hope this isn't homework I am helping with......

So you have xml file eg:-

<br />
<myxml><br />
   <times open="07:30" close="09:30" /><br />
</myxml><br />

And you want to know how long until it opens. Timespan is the difference between two times. If you want to know how long it is until the shop opens, then you need two things. The current time, and the time it opens.

I am assuming you now have "07:30" stored in a string. I am also assuming that you want to know this information about 'today', and not any day in the future.

C# DateTime class, as has already been mentioned, must have both a date and time portion.

To get the current time :-

System.DateTime currentTime = System.DateTime.Now;

As I am writing this, this will give you:

02/05/2007 15:26:34

OK. That is the time now. You now want to know the time (today) when your shop/office etc opens.

So, take the current datetime (currentTime) and replace the time portion with your time.

System.DateTime openTime = System.DateTime.Parse(currentTime.ToShortDateString() + open + ":00" );

The extra ":00" is because a valid time (I think) needs hours:minutes:seconds and yours ("07:00") doesn't have this.

So you now have currentTime and openTime.

If you get the timespan of these, and use the TotalMinutes member, you get the number of minutes until the shop opens, or the number of minutes it has been open if this number is negative.

TimeSpan open = nowTime - openTime;<br />
int MinutesUntilWeOpen = open.TotalMinutes;

Is this homework or a real requirement? Post what you have tried up until now - it makes understanding your requirement a lot easier.

Regards

Angel
*********************************************

Anka_Ame2-May-07 5:01

2-May-07 5:01

Thanks for trying to help me, but I dont want to make that. I want only to show the hour I read it from the Xml file. That's the problem, because I tried it and it shows something like 00:00, and not 07:30, like it should.

Malcolm Smart2-May-07 5:02

2-May-07 5:02

OK - lets try again. Show me the whole function that you have at the moment. Show me your input, and what you expect as output.

Regards

Angel
*********************************************

Anka_Ame2-May-07 5:10

2-May-07 5:10

this is the function which reads the Xml File and is part of a class Cities.
public class Cities : List<city>
{
public void OpenCityList(string filename)
{
DataSet cityDS = new DataSet();

try
{
this.Clear();

cityDS.ReadXml(filename);

DataRowCollection cities = cityDS.Tables[0].Rows;

foreach (DataRow city in cities)
{
this.Add(new City(Convert.ToInt32(city["X"], CultureInfo.CurrentCulture), Convert.ToInt32(city["Y"], CultureInfo.CurrentCulture), Convert.ToInt32(city["Demand"], CultureInfo.CurrentCulture), Convert.ToString(city["Open"], CultureInfo.CurrentCulture)));
}
}

finally
{
cityDS.Dispose();
}
}
private TimeSpan startHour;

public TimeSpan StartHour
{
set
{
startHour = value;
}
get
{
return startHour;
}
}

public void ShowCityHour()
{

foreach (City cityhour in this)
{
startHour = cityhour.OpenTime;
}
}
}
And in another class, named City I have :
public class City
{
private int demand;
private TimeSpan openTime;
public City(int x, int y, int citydemand, string open)// I am interested about the string open
{
Location = new Point(x, y);
demand = citydemand;

DateTime oTime = DateTime.Parse(open);
TimeSpan openTime = oTime.TimeOfDay;
}

public TimeSpan OpenTime
{
get
{
return openTime;
}
set
{
openTime = value;
}
}
}

It is something like that. I take the data from the Xml file and I store it in the string open, and I want to convert it to time, because after that I will have to sort the whole list in order of the hours.

Luc Pattyn2-May-07 5:24

Luc Pattyn

2-May-07 5:24

Anka_Ame wrote:
foreach (City cityhour in this)
{
startHour = cityhour.OpenTime;
}

What does the variable startHour (and the property StartHour) mean in a list of cities ??
and why is a foreach loop used to set it (to whatever happens to be the last city.OpenTime) ?? in a method called Show... where nothing gets shown Confused | :confused:

Luc Pattyn

[My Articles]

Anka_Ame2-May-07 5:36

2-May-07 5:36

that's not my problem. I just want to read the value from a Xml file and to convert it to time, in a string without date.

Malcolm Smart2-May-07 5:50

2-May-07 5:50

You can't have a time without a date. You keep using TimeSpan. That shows the difference between two times / dates - unless I am mistaken. Anybody?

You have two options - convert all times to 'today' + your time. You can then sort them.

or

Or convert your timestrnig to an integer, throw all the ints into a collection and sort them.

string myString = "07:30"

int myTime = int.Parse( myString.Substring(0,2) ) * 60;
myTime += int.Parse( myString.Substring(3,2) ) ;

This will give you the time in minutes, as aninterger. (from memory, so could be typo's etc);

Regards

Angel
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