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Hi,
there is an alternative solution to polling. The technique itself is based on the observer pattern. The model (database etc.) informs all before registered listeners about a change in the model. The listener itself can then react accordingly.
You have two options to implement this:
1) Some database-server can inform registered applications (through the connection) about changes in the database. Check if you DBMS can do this (look for event or sth. similar).
2) Implement a layer which communicates between different hosts. Then use this layer to send a message to all registered applications that you performed a database change. (You should avoid using this solution. Better use your polling mechanism)
Hope this helps.
Regards
Sebastian
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1. The target database should be mssql 2k, so dose it contain an event for supporting this feature? or any keyword can help for search? I don't know what kind of term can be used for this "feature".
2. New layer for communication should not work if my target is 2 tier (client program and mssql database), so I don't know where should place the layer if without server application.
Thanks~
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FYI, I've read on and noticed you need this to work with MSSQL Server 2000.
You've said little about your scenario so it's a bit tricky to give any advice. So this is just some general info instead.
The database does not provide anything that makes it directly easy to provide an event in your application. It is possible though. One way is to write an extended stored procedure in C++ that notifies your application (for example using a message queue) that the update has taken place, and then call this from a trigger in the database.
Another option is available if the database is (supposed to be) accessed only via your client app and you can update all installed clients before the feature becomes (fully) functional. In this case you could use remoting or message queues or web services or even sockets (if you like to needlessly complicate things and reinvent the wheel  ) to notify all clients when any client has just modified the data in question.
To be honest, I think polling is a better option. Just remember that if you've got loads of clients and poll frequently it will generate considerable load on the database and it may be smart to put a caching server in the middle. 500 clients polling every 5 seconds is 100 requests per second. If you've got such a case, consider making an app that polls the db every 5 seconds and updates a cached value (such as a timestamp). Then clients can poll this app (which of course responds based on the cached information) without having to acquire shared locks in the database and the rest of the overhead of executing some query a hundred times per second.
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Hello I want to draw a text along an array of Points
Any suggestion for a good approach ?
Thanks for any help
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Do some research on the GraphicsPath class.
That should give you some ideas.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
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Thank you
Yest it sounds interresting
I'm trying to figure out what are the "Byte [] types" in the constructor of a Graphics path
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baranils wrote: I'm trying to figure out what are the "Byte [] types" in the constructor
I wouldn't worry too much about that for now. I don't believe it will help to solve your problem.
Look at GraphicsPath.AddString and GraphicsPath.Warp methods.
[Edit]
Also take a look at this[^] article from here on CP. It's in VB but I'm sure that will not be a problem. There are loads of code converter apps on the web, if you are unable to do it yourself.
[/Edit]
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
modified on Thursday, April 16, 2009 6:53 AM
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I see !
So finaly GraphicsPath needs a TransformMatrix !
I was expecting that the graphicpath string will automaticaly follow the path defined by the array of point
So what makes the worth of the GraphicPath for this purpose ?
Maybe it will be more simple to use a Graphics.DrawString directely, cutting the string into small pieces
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I've just edited my previous post. Take a look at that, and come back if you still have problems.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
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Just in case you are still having difficulties, I have found a source in C# here[^]. Jolly good it is too.
Hope this helps. 
baranils wrote: I was expecting that the graphicpath string will automaticaly follow the path defined by the array of point
Come along now, this is MS we are talking about. Do you really expect that they would do anything to make our lives easier? 
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
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Thank you very much
This is a piece of work ! 
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It's a pleasure. Your question raised my interest, so I did a bit of rooting around, and got lucky.
Although your English is very good, I am guessing that it is not your first language (your location also gives a clue). So FYI you might want to be a little careful about using the phrase:
baranils wrote: This is a piece of work
In colloquial English it actually means the opposite of what I think you meant. At least what I hope you meant. As an example if you know a particularly nasty man, you might say "Now he's a piece of work isn't he?".
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
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Get it !
Better to say : it's not a piece of cake
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Hello all!
I'm wondering if anyone has any idea to generate specific frequencies?
I am aware of Console.Beep(), but that plays through the PC-Speaker (Or Console Speaker, as it says in the tooltip)
I'm wondering if there's a way to do this to play through your regular sound device (Eg: Speakers / Headphones)
I thank you for your time!
- Reelix
-= Reelix =-
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The easiest way I know of is to use the system.media.soundplayer class - admitedly this only plays .WAV files, but it should be easy to create the frequencies you want as individual files.
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All 100K+ of them? :p
-= Reelix =-
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Hmm. Might take a little time then.
Why so many - the human hearing range is only 20 -> 20,000 Hz. Are we writing software for bats now?
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System.Media.SoundPlayer has a constructor overload that has a Stream parameter[^] so you can construct your waveform in a MemoryStream and pass that to the SoundPlayer's constructor.
DaveBTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)
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Wow - I never knew about that!
Thanks!!!
-= Reelix =-
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Hi All,
Which data type to be use while my value is 21 digit long for mathematical operation.
If you can think then I Can.
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There is not such class in .Net that can accommodate 21 digit numbers yet (well, there is but it's internal). It will be available in .Net 4.0. Until that you will have to search for a third party class that provides such functionality - or write your own one
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how can i get all operations for a given process using c# like operations column in procmon tool?
process operations like (createfile,regopenkey,regqueryvalue...)
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