Re: Use of Reflection - C# Discussion Boards

CWIZO5-Feb-06 19:57

5-Feb-06 19:57

Well that is really up to you.
You can use simple txt files, or XML or even database.

And there is a loat of information about these topics on this site and the internet, so searh a little.

And I think there are even tutorials about logging on this site...

Q:What does the derived class in C# tell to it's parent?
A:All your base are belong to us!

the problem about mixed language(C#+vc.net)

gary.ruan4-Feb-06 20:32

gary.ruan

4-Feb-06 20:32

i passed the value get from below:

-------------
///////////////////////////
C#:
[System.Security.Permissions.PermissionSet

(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
protected override void WndProc(ref Message m)
{
if (m.Msg == 55 && Drvloaded)
{
long test = dp.OnReply(Convert.ToUInt32(m.WParam.ToString()),

m.LParam.ToInt32());

}
base.WndProc(ref m);
}
/////////////////////////////
vc.net
long OnReply(UInt32 wParam,long lParam);
-------------

then after the process by vc.net,i want to pass back some vale(type about

"char/long/WORD..etc) to c#

how i can work this out on "vc.net",thanks

ps:
vc.net,CLR Project

Debug Visualizer

Roger Alsing4-Feb-06 20:11

Roger Alsing

4-Feb-06 20:11

Hi,
Have anyone tried to apply a custom debugvisualizer by decorating your target calss with the DebugVisualizer attribute?

I cannot use the global assembly:debugvisualizer way as all samples use because my types are runtime emitted.

so i figured that i could decorate my classes with the attribute instead and then reffer to the visualizer type as a fully qualified type name (which should should be possible according to the docs, i should just use the string based ctor)

however i get file not found when i do so , ive picked the fully qualified name from the type and also installed my visualizer in the "C:\Program\Microsoft Visual Studio 8\Common7\Packages\Debugger\Visualizers" folder as im supposed to.

but still no luck..

is there anything special I need to do in order to reffer to the visualizer type as a string?

http://www.puzzleframework.com

Use of Reflection

Ashwani_kumar4-Feb-06 19:20

Ashwani_kumar

4-Feb-06 19:20

I have studied reflection in .Net. Through reflection we can get the entire information of assembly and also able to generate the dynamic assemblies.
But what is the practical use of Reflection.
Where we need to generate dynamic assemblies?

Ashwani

Re: Use of Reflection

emran8344-Feb-06 19:29

emran834

4-Feb-06 19:29

Hi,
May be there could be some good use of this feature but to me, it is tooooooooo much disappointing feature of .NET , Now, Whatever program we are making, other people can see the source code of our program through this feature, what could be worse feeling than this for a programmer.

emran

Re: Use of Reflection

S. Senthil Kumar4-Feb-06 19:57

S. Senthil Kumar

4-Feb-06 19:57

Reflection doesn't allow you to look at the source code, it only allows you access to information about types in an assembly and provides an API to do things with them.

Disassemblers work by looking for the metadata information in the executable and reverse engineering IL back to the source language. This is possible because .NET is a managed environment and binaries must contain metadata and high level code to be able to be executed.

Regards
Senthil
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Re: Use of Reflection

S. Senthil Kumar4-Feb-06 19:53

S. Senthil Kumar

4-Feb-06 19:53

The most practical use of reflection I've found is for supporting plugin architectures. You can load any arbitrary assembly and iterate through the types, insantiate them and do all sorts of operations you want on them.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: Use of Reflection

leppie4-Feb-06 22:02

leppie

4-Feb-06 22:02

Ashwani_kumar wrote:
But what is the practical use of Reflection.

The use of reflection in base classes to find out whats happening in the inherit class is very practical, eg:

class Menu : Attribute {}

abstract class A
{
  // in ctr look for methods containing Menu
  // then simply USE that info for your use
}

class B
{
  [Menu]
  void Foo(){}
}

xacc.ide-0.1.2.3
Now with full keyboard customization

Re: Use of Reflection

Colin Angus Mackay4-Feb-06 23:30

Colin Angus Mackay

4-Feb-06 23:30

Ashwani_kumar wrote:
But what is the practical use of Reflection.

There are many uses of reflection.

NUnit uses reflection to work out what unit tests to run, and also how to interpret some of the results (for example, you can attribute a test with [ExpectesException()] which is also finds through reflection)

Serializing and Deserializing classes uses reflection to build or extract information from the XML file.

DotNetNuke uses reflection to take information from the database and populate the business objects. A more powerful example of the same idea is NHibernate.

Reflection is useful in factory patterns in order to instantiate the correct class.

The list goes on and on and on.

ColinMackay.net
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucius
"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

Sharing code over multiple sub domains?

Highwave4-Feb-06 18:17

Highwave

4-Feb-06 18:17

Hi all,

I was wondering if its possible to share the same code over multiple sub domains?

Basically what I want to do is to offer rebranded subdomains with a seperate css and home page, but running off the same code base and DB. So each subdomain would have its own default.aspx & css files, but everything else would be running off common code. Would this be possible?

Thanks in advance for any tips! Smile | :)

Dave

Re: Sharing code over multiple sub domains?

Guffa5-Feb-06 5:49

Guffa

5-Feb-06 5:49

Perhaps if you set up an application with subfolders containing the pages for the subdomains, and for each subdomain set up a web without an application. I haven't tried this, so I don't know if it would work at all.

---
b { font-weight: normal; }

2 tasks at the same time with Background Worker

emran8344-Feb-06 17:21

emran834

4-Feb-06 17:21

Hi, I have started using Background Worker Component of C# 2005 Express and I am enjoying it. I thought I dont need to learn MultiThreding Theorys as I am comfortable to use it. But I was wondering, If I command to background worker, they cant do their task at the same time. The first one finishes its task and then 2nd one starts. So, I am thinking, was it supposed to be like that or I am missing something in my code.

Cant I do 2 simultaneous work at the same time with background worker ?

Thanks
Emran

-- modified at 23:24 Saturday 4th February, 2006

Re: 2 tasks at the same time with Background Worker

Ravi Bhavnani4-Feb-06 17:39

Ravi Bhavnani

4-Feb-06 17:39

Each BackgroundWorker component executes an operation on a separate thread, so AFAIK calling the components' RunWorkerAsync() methods should create 2 parallel threads.

/ravi

My new year's resolution: 2048 x 1536
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Re: 2 tasks at the same time with Background Worker

emran8344-Feb-06 19:42

emran834

4-Feb-06 19:42

Hi,
thanks for reply.
Ok, then What is the difference between regular multithreaded programming and using Background worker ! Is the background worker is direct replacement of using thread coding !!

Re: 2 tasks at the same time with Background Worker

S. Senthil Kumar4-Feb-06 19:58

S. Senthil Kumar

4-Feb-06 19:58

Yeah, it's a more convenient way to do things asynchronously.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: 2 tasks at the same time with Background Worker

Ravi Bhavnani5-Feb-06 3:45

Ravi Bhavnani

5-Feb-06 3:45

emran834 wrote:
Is the background worker is direct replacement of using thread coding

Yes. As S. Senthil Kumar said, it's a more convenient way of writing code to perform a task in a separate thread. Among other things, BackgroundWorker provides a convenient interface for receiving progress notifications and cancelling the task.

/ravi

My new year's resolution: 2048 x 1536
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ravib(at)ravib(dot)com

Timed Backup

Sean894-Feb-06 16:42

Sean89

4-Feb-06 16:42

I am writing a program that backups files/directories to a specified destination directory. To make the program a little more useful I would like to have it backup the files automatically at a certain time during the day. The only way of doing this that I can think of is using a timer that runs in the background, but I am assuming there is a more efficient approach Confused | :confused:

Any help is appreciated. Laugh | :laugh:

Re: Timed Backup

Ravi Bhavnani4-Feb-06 17:31

Ravi Bhavnani

4-Feb-06 17:31

Sean, your approach of using a timer seems like a sound one. However, be aware that there are three types of timers in the FCL. See this[^] MSDN article for a nice explanation.

/ravi

My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com

Re: Timed Backup

Sean894-Feb-06 17:45

Sean89

4-Feb-06 17:45

OK i'll check it out thanks.

Re: Timed Backup

Wayne Phipps5-Feb-06 2:35

Wayne Phipps

5-Feb-06 2:35

You may also consider supporting command line arguments in your backup program.

This way different backups could be launched via batch file or by using Windows Scheduler.

Just remember that when using the scheduler under WinXP, you specify the User whos credentials are used to run the task and that account MUST have a password set.

Hope this helps.

Regards

Wayne Phipps
____________

Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog

Re: Timed Backup

Sean895-Feb-06 5:11

Sean89

5-Feb-06 5:11

Thanks to both of you.

I eventually found an article right here at the code project on timers that has just what I am looking for.

Thanks again,
Sean

single quote error in SQL

emran8344-Feb-06 14:25

emran834

4-Feb-06 14:25

Hi,
I am getting an error in SQL UPDATE statement when user enters single quote character in textbox.
I used following regex to remove the single quote before submitting to SQL UPDATE Statement.
But still SQL is catching that single quote everytime even after filtering from regex. Very wondering. Can you tell me why is this happening !!

string question = rtxtInterViewQuestionSTAR.Text.Replace("\'", "").Trim();
string question = Regex.Replace(question, "\'", "", RegexOptions.Singleline | RegexOptions.Multiline).Trim();

UpdateCommand.CommandText = @"UPDATE star_interview_qa SET question ='" + question + "', strategy = '" + strategy + "', situation_task = '" + situation + "', action = '" + action + "', result = '" + result + "', sequence_no = " + sequence_noTextBoxSTAR.Text + " WHERE (id=" + lblIDqASTAR.Text + ")";

thanks and regards
EMRAN

Re: single quote error in SQL

Colin Angus Mackay4-Feb-06 15:16

Colin Angus Mackay

4-Feb-06 15:16

emran834 wrote:
I am getting an error in SQL UPDATE statement when user enters single quote character in textbox

This is a symptom of code that is highly susceptable to a SQL Injection Attack. A way that a malicious user could attack your database through the application. You may want to read SQL Injection Attacks and Tips on How to Prevent Them[^]

The above article will explain why this happens, and how to fix it and improve the security of your application's database access.

ColinMackay.net
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucius
"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

Re: single quote error in SQL

emran8344-Feb-06 17:22

emran834

4-Feb-06 17:22

Hi, thanks , I found the error and solved it. Smile | :)

Re: single quote error in SQL

S. Senthil Kumar4-Feb-06 19:59

S. Senthil Kumar

4-Feb-06 19:59

Fixing that error might solve your immediate problem, but leaves your code susceptible to SQL injection attacks. Do have a look at Colin's article (link in the post above).

Regards
Senthil
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