New to C# Question - C# Discussion Boards

Tim Kohler10-Dec-03 3:54

10-Dec-03 3:54

Heath, I was able to get around this by resorting to interop. I just wrapped a call to the CreateFile function and then instantiated a FileStream object using the file handle (IntPtr) returned from CreateFile. Once I took this route everything works fine. It looks like there's a bug in the FCL when the FileStream class goes to open the files.

Anyway, just an FYI.

thanks again
Tim

Creating XML Documents

MrEyes9-Dec-03 5:28

MrEyes

9-Dec-03 5:28

This thread applies to this board and the XML board, so i tossed a coin and it came here.

I am attempting to create an XML document in C# by parsing values out of a dataset, unfortunately I cannot simply use dataset.WriteXml() as it isnt powerful enough to handle what I need to do.

I understand the basics of using XmlDocument but I am having trouble navigating around the nodes. So if anybody has any guidance or links to related tutorials the assistance would be greatly appreciated.

The following is a basic summary of my problem :

The dataset I am using (and have no control over) has the follow structure :

type value
2 valA
1 valAA
1 valAB
2 valB
1 valBA
1 valBB
1 valBC
2 valC

Now this is structured in such a way that, all the type 2 values are parents, and all the type 1 values directly under it are children of that parent.

Now the XML document I am attempting to create should have the following format :

<data>
 <parent>
  <value></value>
  <child>
   <value></value>
  </child>
 <parent>
</data>

So if I was to produce an XML document using that template and the dataset above I would have the resulting XML :

<data>
 <parent>
  <value>valA</value>
  <child>
   <value>valAA</value>
  </child>
  <child>
   <value>valAB</value>
  </child>
 <parent>
 <parent>
  <value>valB</value>
  <child>
   <value>valBA</value>
  </child>
  <child>
   <value>valBB</value>
  </child>
  <child>
   <value>valBC</value>
  </child>
 <parent>
 <parent>
  <value>valC</value>
  <child>
   <value>valCA</value>
  </child>
 <parent>
</data>

I have managed to get as far as adding the parents to the XML doc, but I am failing when I try to add children to the parent node.

post.mode = signature;
SELECT everything FROM everywhere WHERE something = something_else;
> 1 Row Returned
> 42

Re: Creating XML Documents

MrEyes9-Dec-03 6:02

MrEyes

9-Dec-03 6:02

As usual, I "imaginered" a solution about 10 seconds after asking the question, but I thought I would run it pass you guys as I have a nack for not coming up with the most elegant solutions.

XmlDocument xdoc = new XmlDocument();
xdoc.LoadXml("<?xml version='1.0' encoding='UTF-8'?><data></data>");
XmlNode xnode = xdoc.DocumentElement;
XmlElement xelement;
XmlElement parent = null;
foreach(DataRow row in ds.Tables[0].Rows)
{
	if ((int)row["type"] == 2)
	{
		xelement = xdoc.CreateElement("parent");
		xelement.InnerXml = string.Format("<value>{0}</value>", row["value"].ToString());
		xnode.AppendChild(xelement);

		parent = xelement;
	}
	else
	{
		xelement = xdoc.CreateElement("child");
		xelement.InnerXml = xelement.InnerXml = string.Format("<value>{0}</value>", row["value"].ToString());
		parent.AppendChild(xelement);
	}
}

post.mode = signature;
SELECT everything FROM everywhere WHERE something = something_else;
> 1 Row Returned
> 42

<
>

Re: Creating XML Documents

Heath Stewart9-Dec-03 6:24

Heath Stewart

9-Dec-03 6:24

That's about what I'd do, although you should use the XmlNode methods for creating elements, creating their attributes and assign them values, and assign the values for the elements rather than using string.Format. It works, but there is no validation and it won't take into account namespaces should you ever use them.

You could also create an instance of an XmlTextWriter and use it's methods like WriteStartDocument, WriteStartElement, ... WriteEndElement, and WriteEndDocument. These methods are fully namespace-aware. It basically amounts to writing-out the XML document itself instead of creating one in memory and then writing it.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++
-----END GEEK CODE BLOCK-----

long path to short path

elena123459-Dec-03 5:12

elena12345

9-Dec-03 5:12

HI,

My program has to trigger a dumb application that won't take paths with spaces. Roll eyes | :rolleyes:

Do you know if there is a built in function in C# that translates long file paths to short file paths.

Thank you,

Elena

Re: long path to short path

Heath Stewart9-Dec-03 6:20

Heath Stewart

9-Dec-03 6:20

There is nothing in the .NET base class library that does this (at least nothing public that I can remember / find), but - if your app runs on Windows 2000 or higher (any NT-based system) - you can P/Invoke the function PathGetShortPath:

[DllImport("shell32.dll", CharSet=CharSet.Unicode)]
public static extern void PathGetShortPath(string path);

You pass the long path into the method and after it returns path contains the short path.

If you need something that works on all operating systems that .NET runs on, you'll have to enumerate each directory and the filename and change it to the 8.3 filename format. It's been a long time since I've worked with these, so you might want to check the PSDK to see if it documents how similarily named files or directories are resolved using the "~N" notation (like "MICROS~1", "MICROS~2", etc.).

You should also trying googling for the solution. I'm sure someone else has had to deal with this before.

Re: long path to short path

Stephane Rodriguez.9-Dec-03 21:24

Stephane Rodriguez.

9-Dec-03 21:24

Does not work on NT. It's only for 2000 and higher.

This API function call works on both OSes : ["kernel32.dll"] GetShortPathName(string szLongPath, string szShortPath, long dwLength).

RSS feed

New to C# Question

Larry J. Siddens9-Dec-03 4:07

Larry J. Siddens

9-Dec-03 4:07

How do you get the XP style using C#?

Larry J. Siddens

Re: New to C# Question

Colin Angus Mackay9-Dec-03 4:35

Colin Angus Mackay

9-Dec-03 4:35

It is not built in unfortunately. However, you have come to the right place. Search CodeProject for XP Style[^] or click the previous link.

--Colin Mackay--

"In the confrontation between the stream and the rock, the stream always wins - not through strength but perseverance." (H. Jackson Brown)

Enumerators in .NET: See how to customise foreach loops with C#

Re: New to C# Question

Heath Stewart9-Dec-03 6:10

Heath Stewart

9-Dec-03 6:10

I wrote an article here: http://www.codeproject.com/csharp/dotnetvisualstyles.asp[^]. If you target .NET 1.1 or higher, you can also call Application.EnableVisualStyles BEFORE you call Application.Run in your entry point (Main). This only works on .NET 1.1 and higher, though, and achieves the same functionality as what I document in my article (which works for .NET 1.0 and higher).

Re: New to C# Question

Larry J. Siddens9-Dec-03 11:29

Larry J. Siddens

9-Dec-03 11:29

Heath,

It was easy to use the Application.EnableVisualSytles() and make sure the controls FlatStyle was "System". Also, It worked in the C++ environment too!

Cool!

Big Grin | :-D

Larry J. Siddens

Re: New to C# Question

Heath Stewart9-Dec-03 11:33

Heath Stewart

9-Dec-03 11:33

Note that C++.NET (Managed C++, or MC++) compiles to the same thing as C#, VB.NET, or any other languages targeting the CLR, so long as your MC++ is written using purely managed code (no mixed mode). This is important to understand: all managed languages compile to (roughly) the same thing: IL. They also have access to the base class library, as well as other assemblies no matter source language they were written in - they all contain IL code.

Re: New to C# Question

Huseyin Altindag9-Dec-03 10:57

Huseyin Altindag

9-Dec-03 10:57

Hi Larry
I think I´ve got something for you
I can send you as attached zip file
email me

Huseyin

First Call to Function does nothing: c#

Goodspeed20029-Dec-03 3:50

Goodspeed2002

9-Dec-03 3:50

I am building an ASP.NET Web site with C#. The design is very much like a portal, where I can load/unload different controls withing the default page. In one of the controls, a user clicks a button to add an item to a "shopping cart", in another control. The first call to my "Add to Cart" function does nothing, however, subsequent clicks on the button work fine.

Any advice on this would be greatly appreciated.

Thanks,
Ben

Re: First Call to Function does nothing: c#

Heath Stewart9-Dec-03 6:08

Heath Stewart

9-Dec-03 6:08

It sounds like you're not loading controls in the right event handlers. There is a specific order to how things are handled (like the Page.Load event fires before a post-back event like a ServerClick or Button.Click event). If you look at some of the events in the SDK documentation for WebControl derivatives, there is a link that describes the order in which events are fired.

Re: First Call to Function does nothing: c#

Goodspeed20029-Dec-03 12:43

Goodspeed2002

9-Dec-03 12:43

Thank you for your response, however I can not seem to find what you suggested in the documentation. Could you be more specific on where I can find this in the SDK documentation?

Thanks a million.

Ben

Re: First Call to Function does nothing: c#

Heath Stewart9-Dec-03 14:13

Heath Stewart

9-Dec-03 14:13

Control Execution Lifecycle[^]

How to validate regular expression pattern?

gokselm9-Dec-03 3:30

gokselm

9-Dec-03 3:30

Hi,

I want to ask a question about Regular expressions.
I want to validate the regular expression pattern if it is written correctly or not? I do not want to test a string against to a regular expression pattern but the regular expression pattern itself.
Is there a way?

Kind Regards

Re: How to validate regular expression pattern?

Heath Stewart9-Dec-03 5:53

Heath Stewart

9-Dec-03 5:53

Just create a new instance of the RegEx. If the regex is invalid, an exception is thrown (this is documented in the class constructor information):

try
{
  Regex re = new Regex("/mypattern/");
  Console.WriteLine("The regular expression is valid.");
}
catch
{
  Console.WriteLine("The regular expression is invalid!");
}

If you move the re declaration outside, you can use it if it's valid after the catch (but then the catch should return or something to keep from trying to use the invalid Regex object).

Re: How to validate regular expression pattern?

gokselm10-Dec-03 11:35

gokselm

10-Dec-03 11:35

Thanks for your help Heath.

Change Notification

mkomasi9-Dec-03 2:50

mkomasi

9-Dec-03 2:50

Hi,

I want to write a program that send a notififcation when files or folders in a path has been changed. So I've used FindFirstChangeNotification and WaitForMultipleObjects (same as a sample in MSDN document).

As I read the document when I use INFINITE for time-out of wait function, it will not be timed out. But in my sample after about one minute, wait function will be timed out.

Do you know what's the problem?

Mehdi

Re: Change Notification

Heath Stewart9-Dec-03 3:02

Heath Stewart

9-Dec-03 3:02

You should be using the FileSystemWatcher component instead. It already wraps all the native functionality up in an easy-to-use component. You can configure the FileSystemWatcher to watch for new, changed, or deleted files and it will fire events when what you want to watch occurs (like changed files or directories) with information about what was changed (one tip: the Changed event is fired three times for each change regardless of file size - after lots of research into event the native methods that the FileSystemWatcher wraps, I still can't figure out why - just make sure your code accomodates that).

As far as your problem goes, are you actually doing this using C#? INFINITE is actually a pre-proc definition for 0xffffffff (you could declare this as a const in C#) and if you're passing this as a string, the function will most likely use the default timeout.

Folder Permissions

Mauricio Ritter9-Dec-03 2:50

Mauricio Ritter

9-Dec-03 2:50

Hi guys,

I need to give permission to an specific folder to a user using C#. Does anyone ever done that ? Is there any class capable of changing files and folders permissions in .NET ?

thanks in advance

Mauricio Ritter - Brazil
Sonorking now: 100.13560 MRitter

English is not my native language so, if you find any spelling erros in my posts, please let me know.

Re: Folder Permissions

Heath Stewart9-Dec-03 2:56

Heath Stewart

9-Dec-03 2:56

No, there are no classes in the .NET base class library that can do this, but there are ways you can P/Invoke the necessary functions. Search the comments for this forum, as I know we've talked about it before. I also remember seeing an article or two here on CP about the topic as well.

Design Technique

Ken Galer9-Dec-03 2:36

Ken Galer

9-Dec-03 2:36

When initially laying out the project, or a portion of the project, is it better to start with the interfaces and save the implementation code until later or just write the classes and then write the code that uses them?

Stated another way, Top down or Bottom up?

Thanks,

Ken Galer
Electrical Engineer
Preferred Utilities Corp.
Danbury, CT 06810

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