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Is it possible to create a ISAPI filter in .NET. I had gone through a couple of articles that did not seem to help me.
My purpose for this filter is I want to block access to a site if the Request comes from certain IP address.
How do I go about creating one. Can some one please help me with it. 
Leejo
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Is it possible? Yes. Practical? No.
There is a bunch of Interop code that has to sit between your Managed C# code and the Unmanaged code world of IIS. This just adds a bunch of overhead to each and every request going to the web server. That means you're sacrificing your web servers performance to use a managed language.
If this is really how you want to go about it, write it in C++. I don't think you'll find any examples of doing this in C#. Oh! You'll also probably have to write a management utility to go along with this filter. How else are you going to tell the filter what addresses to block?
But, if all you want to do is block requests from certain IP's, then that what the firewall is for. Put the block where it belongs and leave the web server running as little code as possible to do its job. This will only result in better stability and easier management of the server.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Thank you for the reply.
Actually we have a Filter running on the server. It was developed in c++ couple of yrs back. I was wondering whether I could port that code to .NET.
The actual functionality that this filter is supposed to do is block Web Page requests that come from certain Countries and allow page requests from certain countries.
Can I get this logic working using Will ISAPI extensions and ISAPI filters
Leejo
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Sure, you could move the logic to a newer .DLL. .NET won't have anything to do with this though, since ISAPI filters have no support in the .NET Base Class Library.
If you want to get this to work in Managed Code (C#, VB.NET, Managed C++), you could. But like I mentioned before, there is a performance penalty for going between managed and unmanaged code. There is a reason why you don't see examples of ISAPI implementations in C#.
If all your doing is blocking requests from certain IP's, nets, or entire countries, your best tool is still the firewall sitting in front of your web server. That's it's entire mission in life! To stop "this and that" traffic from reaching a network its protecting. If the firewall is blocking traffic from IP's, and more importantly, traffic trying to reach certain ports on machines inside the wall, your web server has less work to do that has nothing to do with serving web pages. Why have the web server run more code than it needs to?
By putting up the firewall and blocking everything that isn't going to port 80, or whatever port your using for HTTP, you reduce the attackable surface of your web server, thereby increasing its security and reliability.
Now, as I get off the Soapbox, there are HttpHandler and HttpModule interfaces that can provide similar functionality to ISAPI, though not a complete replacemnet for ISAPI. Look here[^] for some introduction and docs.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hi,I have two questions.
1.Can I use vs2003 with .net 2.0,I want to use datagridview control,which is availabe only in 2.0.
2.Can I use generics in vs2003,msdn say generics is only supported in 2.0 and later.Is there an easy way to use generics in vs2003.
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zhangxinghai wrote: Can I use vs2003 with .net 2.0
No, but the opposite is true.
zhangxinghai wrote: Can I use generics in vs2003
No, also.
zhangxinghai wrote: Is there an easy way to use generics in vs2003.
So why don't you just download the Free Editions of Visual Studio Express ?[^]
------------------------------
"The Soapbox has been so ..."
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Hi!
Short answer: No way.
VS 2002 -> .NET 1.0
VS 2003 -> .NET 1.1
VS 2005 -> .NET 2.0
And you'd better believe MS that generics are not available until .NET 2.0.
Regards,
mav
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hi,
i have been working on a school project for a few weeks, which some settings data need to be store in a external file (such as .txt). I am able to read/write data from/to the text file but the problem is that the settings configuration is always changing. The settings that is key in by user have to be updated to the text file. For the external file i used system IO, streamreader and streamwriter. But i am unable to edit the data in the text file when the user change the settings.
I would like to know if there is any other method in doing the updating of the setting to the text file.
thank you 
orrjiao
-- modified at 3:08 Tuesday 15th November, 2005
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In a datagrid code which is like this
<asp:datagrid id="dgAllCircles" style="Z-INDEX: 102; LEFT: 256px; POSITION: absolute; TOP: 136px" runat="server" pagesize="5" showfooter="True" allowpaging="True" onitemcommand="MyFunct" autogeneratecolumns="False">
<itemstyle font-size="Smaller" font-names="Verdana" horizontalalign="Center">
<headerstyle font-size="Smaller" font-names="Verdana" font-bold="True" horizontalalign="Center">
<columns>
<asp:boundcolumn datafield="SrNo" headertext="Sr No">
<asp:boundcolumn datafield="CircleZip" headertext="Circle Zip">
<asp:boundcolumn datafield="CircleName" headertext="Circle Name">
<asp:templatecolumn headertext="Edit">
<itemtemplate>
<asp:button id="cmdInfo" text="More Info" commandname="Info" runat="server">
<asp:templatecolumn headertext="Delete">
<itemtemplate>
<asp:imagebutton id="Imagebutton3" runat="server" causesvalidation="False" commandname="Delete" imageurl="images\g_Delete.jpg">
<pagerstyle nextpagetext="Next" font-size="Smaller" font-names="Verdana" prevpagetext="Prev">
I am getting event when I click on Next or Prev link of page But I am not hetting the events when I click on button .Any Idea please.
Thank you.
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Sorry ,I don't know where the code has gone but the code was having a datagrid which is havig 5 columns 3 showing data and 2 columns of buttons .
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Hi,
I am writing windows forms with c#, but
from switching from one form to another form,
there is 2 or 3 seconds that require the application to
process some stuff underlined, so the form on the screen
appear to be in messy due to not refresh yet. How
do I solve this problem ?
Thanks
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Do you mean that your app takes 2-3 seconds to do something and so does not process paint messages ? If so, do it in another thread.
Christian Graus - Microsoft MVP - C++
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yes, the app need to save the stuff in database from the previous form
and then load another new form. So you mean process the database operation
in another thread ? Any other simple methods, does it relate to
double buffering problem or other issues ?
Thanks
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ppp001 wrote: does it relate to
double buffering problem or other issues ?
Most probably not. Are you doing some heavy duty painting? If not, it's because of the paint messages not being processed by your application for the 2-3 seconds it takes to save to the database.
Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro
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The painting is light, just simple form. So it is the application
processing that block the painting process. Are there any methods
to solve this problem beside using another thread ?
Thanks
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You can try calling Application.DoEvents at various points in your long running operation, but that's not really recommended. Do you have any restriction on using threads, they should be fairly simple to implement, IMO.
Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro
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Anybody tried it? The NDoc wiki presumably contains a hint how, but the wiki is out of order currently. 
Thanks,
Wout
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Should have checked the sourceforge forum before!
Hmmm, works but generics doesn't yet. 
Wout
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I'm creating a copy of IE using System.Diagnostics.Process and I can pass it any URL at startup, but can't find a way to check what page is open, or to send a new page.
I'm implementing this for html help, and only want to change hte page if the user has navigated away from the current target, otherwise I just want to give the broswer focus again. I'm reluctant to use the help provider class because it opens using the system default browser and our (client provided) style sheets don't work in FF.
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Hi,
I need to convert an hex datetime value 0x43599f4e to a .net datetime. I tried to convert the hex value to an int, but couldn't convert that to a datetime since System.Convert doesn't support conversion of long/int values to datetime. Any ideas?
Thanks
Paul
paul
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PaulLou wrote: I need to convert an hex datetime value 0x43599f4e to a .net datetime.
How is this hex value a datetime ? Where did it come from ?
Christian Graus - Microsoft MVP - C++
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Is it ANSI C time? ie: The number of seconds since 1/1/1970 midnight, the Unix time epoch? If so, then do this...
int intTime = 0x43599f4e;
DateTime myTime = new DateTime(1970, 1, 1);
myTime = myTime.AddSeconds((double)intTime);
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Hi Joshua,
Your solution works great. The values got converted correctly. Thanks a lot for your reply. Can you pl tell me to me why 1970 0101 is taken as the seed value, or the reason behind it. I somehow thought year 1900 would be the year from which the calculations takes place and it is not in .net.
Thanks
Paul
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