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Re: Single/Double.ToString() help

15-Feb-04 16:53

i cannot for the life of me figure out how to get this to return a string that is not formatted in scientific notation

is there a simple guide or set of examples somewhere on how to use IFormatProvider?

msdn doesn't seem to provide any examples

edit: i found an example, it uses a mask... but why does the msdn page mention special characters (d/c/etc) for formating?
where can i find a reference for the available masks?

Werdna15-Feb-04 20:21

Werdna

15-Feb-04 20:21

This is a link to really good site on how to format numbers:
http://authors.aspalliance.com/aspxtreme/aspnet/types/numericformatstrings.aspx

Re: Single/Double.ToString() help

Heath Stewart16-Feb-04 5:55

Heath Stewart

16-Feb-04 5:55

You keep reading the wrong things. Did you try reading the documentation for the NumberFormatInfo, which implements IFormatProvider? You don't even need to specify this for numeric types in string.Format (or any other formatting method like Console.WriteLine). There's also a big section on formatting in the .NET Framework SDK, which should be your first stop for .NET-related documentation, articles, and examples.

There is a simple solution for the scientific notation:

string s = string.Format("{0:e}", myNum);
// OR
s = myNum.ToString("e"); // Also documented in numeric type's ToString docs

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Free C# Training

Tony M John15-Feb-04 15:07

Tony M John

15-Feb-04 15:07

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Re: Free C# Training

Anonymous16-Feb-04 15:08

Anonymous

16-Feb-04 15:08

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Parsing Tab Delimited File

Verdant12315-Feb-04 14:05

15-Feb-04 14:05

is there any way faster then
using split()?

the lines are all the exact same format, with no nulls, etc

this is what i am using:

while (html_sr.Peek() >=0)
{
txt_file = html_sr.ReadLine();
user_info = txt_file.Split('\t');
SQLAction.InsertUpdateUser(int.Parse(user_info[5]),user_info[2],int.Parse(user_info[4]),double.Parse(user_info[3]),date_modified,int.Parse(user_info[1]),int.Parse(user_info[0]));
}

Colin Angus Mackay15-Feb-04 14:24

Colin Angus Mackay

15-Feb-04 14:24

The first obviouse thing is:

while (html_sr.Peek() >=0)
{
txt_file = html_sr.ReadLine();

Why not use:

while((txt_file = html_sr.ReadLine()) != null)
{
    // Do stuff...
}

Now, you no longer have to perform the peek operation and your test is against a value you would get anyway. (Since the RealLine method already performs some operation to determine whether it is at the EOF why duplicate the effort)

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Verdant12315-Feb-04 14:51

15-Feb-04 14:51

Thanks!

i had thought that Readline would throw an exception Smile | :)

now to test and see if this will provide any performance improvement

though i suppose most of my problem is the SQL method...
right now it proceses on average 170 of those lines per second, just trying to squash it down as much as possible

Werdna15-Feb-04 16:45

Werdna

15-Feb-04 16:45

You should probably use some profiler to see what takes most time.
It probably is sql query. Make sure you're not opening the connection with each query, but open it once and do all the queries then.

Verdant12315-Feb-04 16:47

15-Feb-04 16:47

thanks...
the query is actually a single stored procedure, but a complex one

Daniel Turini16-Feb-04 1:59

Daniel Turini

16-Feb-04 1:59

If you're doing INSERTs on a SQL Server from a comma-delimited file, use BCP (Bulk Copy).
It can do up to 100,000 lines/second on a big machine and on desktop machines it processes up to 10,000 lines/second.

Perl combines all the worst aspects of C and Lisp: a billion different sublanguages in one monolithic executable. It combines the power of C with the readability of PostScript. -- Jamie Zawinski

Verdant12316-Feb-04 7:55

how to restrict appearance of child forms

16-Feb-04 7:55

unfortunatly the text file needs to be "processed"

visiontec15-Feb-04 13:29

visiontec

15-Feb-04 13:29

Hi there

How can i restrict the appearance of child forms?
i only want 1 instance of a particular child form
how do i do that?

VisionTec

Re: how to restrict appearance of child forms

Colin Angus Mackay15-Feb-04 14:40

Colin Angus Mackay

15-Feb-04 14:40

visiontec wrote:
How can i restrict the appearance of child forms?

This is ambiguous. Appearance in this context could mean the number of times it appears or the way it looks.

visiontec wrote:
i only want 1 instance of a particular child form
how do i do that?

Apply the singleton pattern to it. Actually, I'm not too sure whether that is completely wise or not in the context of a form. If your not already aware, a "singleton" is a class that only ever has one instance in existance at any time (some more strickter definitions might even say only one instance ever). This is acomplished by making the constructor private, creating static field of the class type and creating a static method that creates the one and only instance or returns the existing instance. If you need to know more about singletons just ask and I, or someone else, will help you out.

Tab Pages Navigation

visiontec15-Feb-04 12:58

visiontec

15-Feb-04 12:58

Hi there

In my mdi app i have a child form which has a tabcontrol on it.
there r 2 pages in that tabcontrol

Now how can i load the child form to show
the start page that i want?

VisionTec

Re: Tab Pages Navigation

Heath Stewart16-Feb-04 5:48

Heath Stewart

16-Feb-04 5:48

You could pass an int to the child form's constructor, and in the constructor set TabControl.SelectedIndex to that int, or do this using the set accessor of a property of your child form, or many other ways. This is a simple object-oriented design (heck, even procedural designs would be simple).

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Remoting?

Kevin Tambascio15-Feb-04 12:39

Kevin Tambascio

15-Feb-04 12:39

Hi,

I am very familiar with DCOM and its inner-workings, but this is my first attempt at doing something with C#.

I want to write a windows service in C# that a ASP.NET webapp or C# application can talk to as a client. The client would have to pass several pieces of information to the service and exit. The service will add the request into a queue and then process it as its leisure. The service will post the results of the request to a ftp site for user's to download. So there is nothing syncronous about this operation. The client does not wait around for the results.

Should I be using .NET remoting to talk to the windows service? If so, should the remoted object be a singleton or a single call? Should the service implement its own queue/thread mechanism, or use the built-in thread-pooling to handle the request queue?

Any ideas/suggestions would be helpful.

Thanks in advance,
Kevin

Marc Clifton15-Feb-04 15:42

Marc Clifton

15-Feb-04 15:42

Kevin Tambascio wrote:
Should I be using .NET remoting to talk to the windows service?

Yup. It's really straight forward to set up what you want to do.

Kevin Tambascio wrote:
If so, should the remoted object be a singleton or a single call?

I prefer the singleton mode because I can make multiple calls on the same instance rather than a new instance.

Kevin Tambascio wrote:
Should the service implement its own queue/thread mechanism, or use the built-in thread-pooling to handle the request queue?

As for this, read my article on .NET's built in threadpooling. http://www.codeproject.com/csharp/threadtests.asp[^] It's intended to service threads that are mostly asleep and do their thing quickly. I'd probably suggest Stephan Stoub's thread pool manager, which you can download from the article.

Hope that helps!

Marc

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Kevin Tambascio16-Feb-04 3:09

Kevin Tambascio

16-Feb-04 3:09

Marc,

Thanks for your help, I hope you won't mind a few more questions.

I got .NET remoting to work between two .exe's, seems very nice so far. If I create the remote object as a singleton (using multiple clients), will functions in that remote object be called from one thread in some order, or just called all at once? Do I have to synchronize those calls to shared objects?

Also, this service will eventually be called from a web app (ASP.NET) instead of a exe. Will each user's instance of the website be able to create a TcpChannel at the same port number to talk to the remote object, or will each of the client's have to have some knowledge of each other to find a unused port number to create that TcpChannel?

Thanks again,
Kevin

Marc Clifton16-Feb-04 9:29

Marc Clifton

16-Feb-04 9:29

Kevin Tambascio wrote:
If I create the remote object as a singleton (using multiple clients), will functions in that remote object be called from one thread in some order, or just called all at once? Do I have to synchronize those calls to shared objects?

Honestly, I don't have a positive answer for that. However, since each instance gets its own AppDomain, I think that there would be multiple instances. I can't imagine it otherwise, actually. So I think you'll have to deal with synchronization yourself.

Kevin Tambascio wrote:
Also, this service will eventually be called from a web app (ASP.NET) instead of a exe.

Hmmm. You mean, on the client side? I don't think you can do that. That's what web services / SOAP is for, I think (again, i'm fuzzy on that).

Kevin Tambascio wrote:
Will each user's instance of the website be able to create a TcpChannel at the same port number to talk to the remote object,

My understanding is yes--the same port number is used. For example, I've been able to connect to my remote object from two different computers on my local network using the same port number. I *believe* that the initial port number is just for saying "hello", and then an unused port number is negotiated. I could be totally wrong though.

Sorry these answers are full of "I'm not sure". If you find out more, It would be great if you could let me know!

Marc

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