Calculate difference between two dates - C# Discussion Boards

OriginalGriff17-Jun-09 5:38

17-Jun-09 5:38

Pete O'Hanlon wrote:
This project is about ~~what I will be doing when I fail my course because I have deprived my village of an idiot~~ 20 pages too short for a pass mark.

FTFY

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How to determine the number of references a program is currently using?

Abul Kayes17-Jun-09 0:26

Abul Kayes

17-Jun-09 0:26

Hi. Is there any ways/ APIs to determine how many references of a certain object/ class a C# program creates/ uses during it's life cycle?

Suppose there's a class Person and in my program several references to Person objects are made. How to determine the number of Person references in my program?

Thanks.

[Kayes]

Re: How to determine the number of references a program is currently using?

OriginalGriff17-Jun-09 0:51

OriginalGriff

17-Jun-09 0:51

Not sure about APIs etc., but the obvious one is to maintain a static int as part of your class and increment it for each constructor. This doesn't "uncount" them when they are GCed though, so it is a total count, rather than a shapshot.

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Re: How to determine the number of references a program is currently using?

Luc Pattyn17-Jun-09 1:10

Luc Pattyn

17-Jun-09 1:10

Yeah, instance counting is easy. BTW: you could decrement the counter in a finalizer.

However reference counting is basically impossible, a reference can be copied without the class or object being aware of that.

Person person1=new Person();
Person person2=person1;

Luc Pattyn [Forum Guidelines] [My Articles]

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Re: How to determine the number of references a program is currently using?

Abul Kayes17-Jun-09 4:56

Abul Kayes

17-Jun-09 4:56

Yeah, that's my point.

[Kayes]

Re: How to determine the number of references a program is currently using?

Abul Kayes17-Jun-09 4:53

Abul Kayes

17-Jun-09 4:53

That's a way. But consider the following. One object is constructed, but two references.

Person p = new Person(); //1 reference to Person p
Person q = p; //2 references to Person p

How to track this?

[Kayes]

Re: How to determine the number of references a program is currently using?

Luc Pattyn17-Jun-09 5:05

Luc Pattyn

17-Jun-09 5:05

you can't, there is nothing to support that in .NET
The GC is based on (a slightly conservative) reachability or "life" analysis, not on reference counting.
why would you need a reference count?
if only for one or a few classes of your own, you could try and implement it yourself, including an override for the = operator. Not sure you can get it all tight though.

Smile | :)

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Calculate difference between two dates

KIDYA17-Jun-09 0:15

KIDYA

17-Jun-09 0:15

Helloo Experts!!

I want to calculate difference between two dates(Day) and display that differnce date like 12\02\09,
In short,
current date:12\02\09

Dispaly date;11\02\09

help me!! Sigh | :sigh:

Re: Calculate difference between two dates

OriginalGriff17-Jun-09 0:33

OriginalGriff

17-Jun-09 0:33

See Timespan class[^]

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Re: Calculate difference between two dates

Baran M17-Jun-09 0:36

Baran M

17-Jun-09 0:36

you can try this,

DateTime d1 = DateTime.Today;
DateTime d2 = DateTime.Today.AddDays(1);
TimeSpan ans = d2.Subtract(d1);

If I didn't get your problem plz explain it.

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Re: Calculate difference between two dates

himanshu256117-Jun-09 0:38

himanshu2561

17-Jun-09 0:38

You can find lots of stuff on how to work with DateTime.
Check http://www.dotnetspider.com/forum/164678-date-difference-using-asp-net.aspx[^]

himanshu

System.Drawing.Image to IPicture and back changes the image

Sander123432117-Jun-09 0:09

Sander1234321

17-Jun-09 0:09

public new static object GetIPictureDispFromPicture(System.Drawing.Image image)
{

System.Drawing.ImageConverter converter2 = new System.Drawing.ImageConverter();

byte[] arraybyt2 = (byte[])converter2.ConvertTo(image, typeof(byte[]));

System.Drawing.Image imageToConvert = System.Windows.Forms.AxHost.GetPictureFromIPicture(System.Windows.Forms.AxHost.GetIPictureFromPicture(image));

System.Drawing.ImageConverter converter = new System.Drawing.ImageConverter();

byte[] arraybyt = (byte[])converter.ConvertTo(imageToConvert, typeof(byte[]));

return System.Windows.Forms.AxHost.GetIPictureFromPicture(image);

}

The function receives a Image that needs to be converted to an ipicture. I found out that during change the image to a ipicture and back to image the size of the array of bytes are different. How come the size of the arraybyt1 and arraybyt2 are different. I'm creating a checksum of the array from bytes and therefor the checksum is also different?

Re: System.Drawing.Image to IPicture and back changes the image

Henry Minute17-Jun-09 1:24

Henry Minute

17-Jun-09 1:24

I am not familiar with IPicture, and therefore this is very much a guess.

Perhaps Image stores data that IPicture doesn't, or vice versa. For example, different sized headers or one stores palette information and one doesn't.

Most image formats have their specifications out on the web somewhere, have a play with google.

Henry Minute

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SQL Data type validation

jonhbt16-Jun-09 23:49

jonhbt

16-Jun-09 23:49

I need to create a method that accepts a string as a parameter and checks whether this parameter is a valid SQL Server datatype or not. Can someone help please?

thanks

Re: SQL Data type validation

himanshu256117-Jun-09 0:46

himanshu2561

17-Jun-09 0:46

Hi,
Change the method parameter from String to SqlDbType.

himanshu

Re: SQL Data type validation

PIEBALDconsult17-Jun-09 9:12

PIEBALDconsult

17-Jun-09 9:12

How about System.Enum.Parse ( typeof(System.Data.SqlDbType) , "datetime" , true ) ?

Re: SQL Data type validation

jonhbt17-Jun-09 23:12

jonhbt

17-Jun-09 23:12

thanks it worked fine for my application

Re: SQL Data type validation

PIEBALDconsult18-Jun-09 4:42

PIEBALDconsult

18-Jun-09 4:42

Glad to be of service.

C# XmlDocument Encoding

Samb198516-Jun-09 22:24

Samb1985

16-Jun-09 22:24

How can i load in a XmlDocument an xml file (from text file) that in the tag contain any type of char ? How can encode this ?

If my file contain char as "&" or "°" there is an exception (Xml.XmlException Errore durante l'analisi di EntityName).

I try with this but don't work:

Encoding enc = Encoding.ASCII;
FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.None);
StreamReader sr = new StreamReader(fs,enc);
string response = sr.ReadToEnd();
XmlDocument xml = new XmlDocument();
xml.LoadXml(response);
fs.Close();
sr.Close();

The exception is Xml.XmlException Errore durante l'analisi di EntityName.

Re: C# XmlDocument Encoding

SeMartens16-Jun-09 22:45

SeMartens

16-Jun-09 22:45

Well as far as I know it is not allowed to use all chars in entity-names. There is a strict rule for tag-names. Maybe you could post a bit of your xml-file, so that we can identify the problem.

Regards
Sebastian

It's not a bug, it's a feature!

Check out my CodeProject article Permission-by-aspect.

Me in Softwareland.

Re: C# XmlDocument Encoding

Samb198516-Jun-09 23:18

Samb1985

16-Jun-09 23:18

The problem isn't the tag-names but their content.

The exception occur when in the content of a tag (<tag> abc & avc n° ) there are particular char as & or °

Re: C# XmlDocument Encoding

SeMartens16-Jun-09 23:45

SeMartens

16-Jun-09 23:45

You could replace all special characters with their escape characters before reading the xml. Maybe this helps.

It's not a bug, it's a feature!

Check out my CodeProject article Permission-by-aspect.

Me in Softwareland.

Re: C# XmlDocument Encoding

Samb198516-Jun-09 23:47

Samb1985

16-Jun-09 23:47

How can i replace it ? can you give me an example of code ?

Re: C# XmlDocument Encoding

SeMartens16-Jun-09 23:53

SeMartens

16-Jun-09 23:53

Not the best method but maybe

response = response.Replace( "&", "&");

By the way, do you have an xml-declaration in your file (sort of <?xml version="1.0" encoding="UTF-8"?> )?

It's not a bug, it's a feature!

Check out my CodeProject article Permission-by-aspect.

Me in Softwareland.

Re: C# XmlDocument Encoding [modified]

Samb198517-Jun-09 0:00

Samb1985

17-Jun-09 0:00

I dont' have an xml-declaration...however if i add it there is always the same exception.

To use replace i must know all possible incorrect char... i would like to find a method valid for all possible char that may occur in the file.

Edit:
if i use utf8 encoding and replace of &, program work well with my current file xml.

I hope in future don't occur another char that create same problem. I think that & is properly of XML standard and so cause this exception.

modified on Wednesday, June 17, 2009 8:14 AM

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