Some Basic Question Related To Image Processing…(C# .Net) - C# Discussion Boards

Re: Eventhandler in C# - How to send parameter

Vikas K.31-Jul-07 1:55

Vikas K.

31-Jul-07 1:55

Yes, This solution works properly! Smile | :)

though a bit advanced for me!
thanks

Re: Eventhandler in C# - How to send parameter

Martin#31-Jul-07 2:05

Martin#

31-Jul-07 2:05

Glad I could help!
Thanks for the feedback!
Smile | :)

All the best,

Martin

How Can use Matlab Files in Visual Studio C# .Net?

zeeShan anSari26-Jul-07 21:38

zeeShan anSari

26-Jul-07 21:38

Hi,
I want include the some Matlab lib files in my C# progrm than what is a procedure to link the matlab with C#.Net?
Smile | :)

Re: How Can use Matlab Files in Visual Studio C# .Net?

Christian Graus26-Jul-07 21:39

Christian Graus

26-Jul-07 21:39

There isn't one, unless matlab comes in dlls you can p/invoke

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: How Can use Matlab Files in Visual Studio C# .Net?

Murali Babu26-Jul-07 23:00

Murali Babu

26-Jul-07 23:00

There is no direct way to use the Matlab files in C# however, using the Matlab Builder for .Net you can convert Matlab functions to .Net methods. Write all the required function in m-code (encapsulate) and build using .Net Builder which will generate a .Net Assembly file which can be used in your C# program.

You will need Matlab version R2006a (with MATLAB Builder for .NET).

Also checkout the website http://www.mathworks.com/access/helpdesk/help/toolbox/dotnetbuilder/[^]

Hope this works!
~Sky

DirectX in C#

legolass26-Jul-07 21:36

legolass

26-Jul-07 21:36

Hi,I have a problem. I have a DirectX application written in C++ and i want to embed it in a C# Windows form. Is that possible and how?

Re: DirectX in C#

Christian Graus26-Jul-07 21:40

Christian Graus

26-Jul-07 21:40

Not really, no, you can't embedd one app in another in a supportable way.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Some Basic Question Related To Image Processing…(C# .Net)

zeeShan anSari26-Jul-07 21:30

zeeShan anSari

26-Jul-07 21:30

I use the following code (obvious not my coding) in my program:

public static bool CovertToGray(Bitmap bmp)<br />
        {<br />
           <br />
            BitmapData bmData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),<br />
                ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);<br />
            int stride = bmData.Stride;<br />
            System.IntPtr Scan0 = bmData.Scan0;<br />
        unsafe<br />
            {<br />
                byte* p = (byte*)(void*)Scan0;<br />
                byte red, green, blue;<br />
                int nOffset = stride - bmp.Width * 3;<br />
                for (int y = 0; y < bmp.Height; ++y)<br />
                {<br />
                    for (int x = 0; x < bmp.Width; ++x)<br />
                    {<br />
                        blue = p[0];<br />
                        green = p[1];<br />
                        red = p[2];<br />
                        p[0] = p[1] = p[2] = (byte)(.299 * red<br />
                            + .587 * green + .114 * blue);<br />
                        p += 3;<br />
                    }<br />
                    p += nOffset;<br />
                }<br />
            }<br />
            bmp.UnlockBits(bmData);<br />
            return true;<br />
        }

Questions are
What is the function of BitmapData?
Why PixelFormat.Format24bppRgb is used?
What is this int stride = bmData.Stride;?
Why unsafe used?
In short I can’t understand the 50% of above code for convert the picture in grayscale format?
I want learn……..please guide me …..I am waiting for your response
Smile | :)

Re: Some Basic Question Related To Image Processing…(C# .Net)

Christian Graus26-Jul-07 21:42

Christian Graus

26-Jul-07 21:42

1 - it contains the bits of the image
2 - probably because 32 bits is a waste of time and < 24 is hard to process
3 - each image in memory has an area at the end of each scanline which does not contain pixels and should not be accessed.
4 - because you can't use pointers in C# outside an unsafe block

This looks like it came from my image processing article, didn't I explain all of this there ?

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

How to convert Struct to array

Morad Kobi26-Jul-07 21:30

Morad Kobi

26-Jul-07 21:30

Re: How to convert Struct to array

Malcolm Smart26-Jul-07 21:35

Malcolm Smart

26-Jul-07 21:35

minimilist question

minimilist answer [^]

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: How to convert Struct to array

Christian Graus26-Jul-07 21:38

Christian Graus

26-Jul-07 21:38

With the ToArray() method

Seriously, your question makes no sense, what is in the struct, that it makes sense to turn it into an array ?

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

CLR-Trigger coded in c# (Express Edition 2005)

jacklynn_mei26-Jul-07 21:25

jacklynn_mei

26-Jul-07 21:25

Hi...

I am newbie in c#, please help me on clr trigger.
I have done a clr trigger and everytime i debug my c# code,an error occured on this part
AIClass.AICheck.checkUserRole();

The error description is like this :->
InvalidOperationException was Unhandled
The requested operation requires a SqlClr context, which is only available when running in the Sql Server process.

I dont know what to do...
And I cannot create a trigger inside Sql Server Express Edition 2005. I did like this:->
create trigger tgAI
on AIEvent
for insert
as
external name
AIAssembly.AIClass.userRoleCheck

and the error appeared:-> Msg 6505, Level 16, State 1, Procedure tgAI, Line 1
Could not find Type 'AIClass' in assembly 'AIClass'.

my code in c# is like this (will be called in the main class in console App.):->
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SqlServer.Server;
using System.Data;
using System.Data.SqlClient;

namespace AIClass
{
public class AICheck
{
//[SqlTrigger(Event = "FOR INSERT", Name = "AI_tg", Target = "AIEvent")]
public static void checkUserRole()
{
SqlTriggerContext tgContext = SqlContext.TriggerContext;
//SqlConnection conn = new SqlConnection("Data Source=DIMENSION3000\\SQLEXPRESS; Initial Catalog=AITania; User Id=sa; Password=123456");
using (SqlConnection conn = new SqlConnection("context connection=true"))
conn.Open();
SqlCommand cmd = conn.CreateCommand();
SqlDataReader reader;
string msg = "";

if (tgContext.TriggerAction == TriggerAction.Insert)
{

//SqlCommand sqlComm = new SqlCommand();
//SqlPipe sqlPipe = SqlContext.Pipe;
cmd.CommandText = "SELECT * FROM INSERTED";
reader = cmd.ExecuteReader();
//sqlComm.Connection = conn;
//sqlComm.CommandText = "SELECT * FROM INSERTED";

//for (int x = 0; x < tgContext.ColumnCount; ++x)
//{
// msg += string.Format("Column {0} {1} been updated{2}", x, (tgContext.IsUpdatedColumn(x) ? "has" : "has not"), Environment.NewLine);
//}
for (int i = 0; i < reader.FieldCount;i++ )
{
msg = msg + reader.GetName(i) + ":" + (string)reader[i] + " ";
}
}conn.Close();

}
}
}

Please help me..

thanks..
-jack-

Re: CLR-Trigger coded in c# (Express Edition 2005)

leppie27-Jul-07 3:21

leppie

27-Jul-07 3:21

You cant use that code outside the SQL environment, you will have to specify a proper SQL connection string.

Re: CLR-Trigger coded in c# (Express Edition 2005)

jacklynn_mei29-Jul-07 16:22

jacklynn_mei

29-Jul-07 16:22

hi leppie..

hem..thanks for the suggestion...but still blur..
so..how do i supposed set the connection string properly..
whenever i debug my project..it came out like this...
The Error:
AIClass.AICheck.checkUserRole();
--> invalidOperationException was unhandled
--> The requested operation requires a SqlClr context, which is only available when running in the Sql Server process.

i have search at msdn help online but still cannot find the answer..
please help me...

thanks a lot
Jac

Anonymous methods

Michael Sync26-Jul-07 21:24

Michael Sync

26-Jul-07 21:24

I'm very new to .NET 2.0 even I have experiences in .NET 1.1.

It would be really great if anyone can give me three or more real scenarios where anonymous methods should be used or where can't be done without those kinda methods.

The main advantages of using anonymous methods that I know so far is that it saves the time of typing.

Thanks in advance.

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

Re: Anonymous methods

Christian Graus26-Jul-07 21:33

Christian Graus

26-Jul-07 21:33

The main reason I would use them is

a - where I define a timer and want to define what it does inline
b - where the method I create relies on the state of variables in the method it was created in

I don't use them much.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: Anonymous methods

Malcolm Smart26-Jul-07 21:37

Malcolm Smart

26-Jul-07 21:37

I've use them on collections a lot, for sorting, extracting etc, but how would you use one with a timer? The concept sounds neat.....go on......post a couple of lines to explain.. Smile | :)

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Anonymous methods

Christian Graus26-Jul-07 21:39

Christian Graus

26-Jul-07 21:39

I just mean that when I create a timer, I'll often make the tick event fire an anonymous method. That way the timer is defined, and what it does is defined, in the same place.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: Anonymous methods

Malcolm Smart26-Jul-07 21:51

Malcolm Smart

26-Jul-07 21:51

Thats slick - didn't know you could do that. I have loads of events firing off to do 1 or 2 lines of code. Humour me here...is the following correct...

System.Timers.Timer t = new System.Timers.Timer();
t.Interval = 100;
t.Elapsed += delegate(object sender, System.Timers.ElapsedEventArgs e) { Console.Write("."); };
t.Start();
while (true)//obviously not a good idea
{
   System.Threading.Thread.Sleep(1000);
}

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Anonymous methods

Christian Graus26-Jul-07 22:01

Christian Graus

26-Jul-07 22:01

Exactly. And, your timer method will be in the scope of the method that created it, which is sometimes very handy indeed.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: Anonymous methods

szukuro26-Jul-07 21:51

szukuro

26-Jul-07 21:51

One great advantage of anonymous methods is that it can access local variables within the regular method scope. For example:

List<int> numbers = new List<int>(new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 });
List<int> primeNumbers = new List<int>(new int[] { 2, 3, 5, 7, });
List<int> nonPrimeNumbers = numbers.FindAll(delegate(int i) { return !primeNumbers.Contains(i); });

If I had used a classic delagate, primeNumbers wouldn't be accessible.

Re: Anonymous methods

J4amieC26-Jul-07 22:07

J4amieC

26-Jul-07 22:07

ack thats so useful and I cant believe I didn't think of it!

There are loads of places where I have Find delegates for the List<> object and Ive had to store a member variable with a parameter that I had accessible in the calling method!

---

How to get answers to your questions[^]

Re: Anonymous methods

Kevin McFarlane26-Jul-07 23:46

Kevin McFarlane

26-Jul-07 23:46

Thanks for pointing this out! Smile | :)

Kevin

Re: Anonymous methods

Michael Sync26-Jul-07 23:47

Michael Sync

26-Jul-07 23:47

Thanks a lot for your answer. Christian Graus,Malcolm Smart and szukuro.

The way I understand is that things that can be done with anonymous method can also be done with delegate. There is no particular case that has to be used the anonymous method.

Michael Sync wrote:
scenarios where can't be done without anonymous methods.

there is no such a case. isn't it?

The advantages of using anonymous methods is that we can organize the code and it can save the time of typing.

So, the usage of anonymous methods is not vital. it's just extra thing that help the developer to write the code quickly (more productivity. Smile | :)

)

That's all.

Is there anything can be added more??

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.