C# Discussion Boards - CodeProject

Shy Agam15-Jun-07 7:15

15-Jun-07 7:15

Here's my answer (not tested):

5 5
False
True
True

5 5:
You instantiate one object, and reference it from two variables.
That's why when you change the Value field by either of the references the changes are "reflected" in the other reference variable.

False:
The Value field is a value-type member.
This means that casting it to an object, demands boxing, which results in the creation of two completly different objects, holding the same numeric value.

True:
It doesn't matter if you cast an object to its parent type.
It still points to the same object in memory.
So its simply doing a reference comparison.

True:
You set both reference variables to point to the same object in memory, and the "==" operator compares their references.

Corrections? Opinions?

Smile | :)

Regards,
Shy.

Re: A concepteual question

Amar Chaudhary15-Jun-07 7:25

Amar Chaudhary

15-Jun-07 7:25

Correct Answer is
5 5
False // here i was wrong
True
True

Thanks for Explanation
Regards
Amar

Non-order-dependent deserialization of objects

Shy Agam15-Jun-07 6:36

Shy Agam

15-Jun-07 6:36

Hello,

If I serialize multiple objects to the same file, is it possible to somehow deserialize them not in the same order?

Thanks in advance,
Shy.

Memory leak issue, memory management of unmanaged code

logicaldna15-Jun-07 6:34

logicaldna

15-Jun-07 6:34

hi
i'm having a issue with memory management in a COM which uses MSXML (cause of memory leak)
if i use a c# wrapper around the COM which is then called from .net webservice will CLR take care of memory management for me( essentially Garbage collection)

if not by design can i force GC to take care of memory leaks in COM
this is very urgent, please help ! Cry | :((

sorry i'm posting it in different forums at a time but hope you will see a desparation :->

Chase your dreams !
http://eminencetech.net[^]

Re: Memory leak issue, memory management of unmanaged code

Shy Agam15-Jun-07 6:39

Shy Agam

15-Jun-07 6:39

The GC does not re-claim unmanaged memory.

Regards,
Shy.

Re: Memory leak issue, memory management of unmanaged code

logicaldna15-Jun-07 6:42

logicaldna

15-Jun-07 6:42

thanks for the reply,
but can i force it in anyway, is it possible if i use COM as RCW

Chase your dreams !
http://eminencetech.net[^]

Re: Memory leak issue, memory management of unmanaged code

Shy Agam15-Jun-07 7:00

Shy Agam

15-Jun-07 7:00

You cannot force the GC to collect objects from unmanaged memory.
The GC works only on objects created by the CLR.
Hence the expression "UNMANAGED memory". Smile | :)

If your COM object contains cleanup methods, use them.

logicaldna wrote:
is it possible if i use COM as RCW

Sorry, but I don't think I know what RCW means...
Maybe someone else here can help you with that.

Re: Memory leak issue, memory management of unmanaged code

logicaldna15-Jun-07 7:04

logicaldna

15-Jun-07 7:04

shyagam wrote:
If your COM object contains cleanup methods, use them

i have tried all and even COuninitialize is not cleaning the memory dam this MSXML Confused | :confused:

thanks anyways
sagar

Chase your dreams !
http://eminencetech.net[^]

Re: Memory leak issue, memory management of unmanaged code

Jimmanuel15-Jun-07 7:19

Jimmanuel

15-Jun-07 7:19

When using COM objects in C# setting an object to null isn't all that's required to signal it ready for Garbage Collection. First a call must be made to Marshal.ReleaseComObject(aComObjectVariable) to decrement it's reference counter in the RCW.

MSDN[^]

Re: Memory leak issue, memory management of unmanaged code

Paul Conrad15-Jun-07 13:57

Paul Conrad

15-Jun-07 13:57

logicaldna wrote:
i'm posting it in different forums at a time

That's not polite and it gets people ticked off and less likely to respond.

"You will see a delete button on each of your posts. Press it." - Colin Angus Mackay

Appconfig File Entry

ramdil15-Jun-07 6:12

ramdil

15-Jun-07 6:12

Hi All,
I am new to c# and i am currently facing a problem in writing to a app config file.I am able to write to a config file if its read only access property is removed.Is there any way to give write permissions to the config file programatically.

Regards
DilipRam

Re: Appconfig File Entry

Jimmanuel15-Jun-07 8:49

Jimmanuel

15-Jun-07 8:49

try

File.SetAttributes(fileName, FileAttributes.Normal);

Re: Appconfig File Entry

ramdil17-Jun-07 22:56

ramdil

17-Jun-07 22:56

Thanks very much..Its working now

Regards
Dilip

Regards
DilipRam

Propety grid

half-life15-Jun-07 6:09

half-life

15-Jun-07 6:09

HI,
i like to know two things :
1. how do i add an Attribute to the Propety grid.
2. how do i add the + in a specific Attribute.

TNKS Smile | :)

kobkob

Trace.Writeline not visible under Vista?

LongRange.Shooter15-Jun-07 5:44

LongRange.Shooter

15-Jun-07 5:44

I have a service loader that issues Trace.Writeline as the servicehosts are loaded. When I ran it under Windows XP everything works as expected. When I run it under Vista in debug mode, dbgView does not see the trace messages.

Does anyone know what I have to do from a policy end to get these messages viewable?

Thanks.

DataGridView custom events

jesarg15-Jun-07 5:15

jesarg

15-Jun-07 5:15

I have recently created a custom DataGridView column type (with my own custom cell type and custom control type inside).

I am trying to make my own custom events to go with the cell/column type, but apparently, the DataGridView was implemented quite strangely, and I'm getting event handlers that should be attached once become attached multiple times, never, or in an inconsistent manner.

Has anyone ever run into this before, and is there any good resource that could help me with this?

UnregisterTypeLib

Zebpic15-Jun-07 2:41

Zebpic

15-Jun-07 2:41

Hello,

I'm writting an application which check the dependency of imports. I have to register some typelibs for this import. After the analysis i want to unregister these typelibs.
But it doesn't work and I don't know why.

This is the exception: "The structure must not be a value class"

Please help me.

Here is my code that doesn't work

<br />
        [DllImport("oleaut32.dll", CharSet = CharSet.Unicode, PreserveSig = false)]<br />
        private static extern void UnRegisterTypeLib(Guid libID,<br />
        ushort wVerMajor,<br />
        ushort wVerMinor,<br />
            LCIDConversionAttribute lcid,<br />
             System.Runtime.InteropServices.ComTypes.SYSKIND syskind);<br />
<br />
<br />
// The struct<br />
<br />
        [StructLayout(LayoutKind.Auto)] <br />
        struct Attr <br />
        {<br />
            public Guid libID;<br />
            public ushort wMajorVerNum;<br />
            public ushort wMinorVerNum;<br />
            public LCIDConversionAttribute lcid;<br />
            public System.Runtime.InteropServices.ComTypes.SYSKIND syskind;<br />
        }<br />
<br />
<br />
<br />
// the code in an methode<br />
typeLib.GetLibAttr(out ppTLibAttr);<br />
<br />
               // Marshal.GetTypeLibGuid();<br />
                Attr structTlb = new Attr();<br />
                <br />
<br />
                Marshal.PtrToStructure(ppTLibAttr, structTlb);<br />
<br />
                UnRegisterTypeLib(structTlb.libID, <br />
                    structTlb.wMajorVerNum, <br />
                    structTlb.wMinorVerNum, <br />
                    structTlb.lcid, <br />
                    structTlb.syskind);<br />

I hope it helps?!

How to add Animation ASP.Net 2.0

khuzwayom15-Jun-07 2:36

khuzwayom

15-Jun-07 2:36

Another one. I would like to know how to add animation on my web page.
I'm using ASP.Net 2.0 (C#)

khuzym

Re: How to add Animation ASP.Net 2.0

Vasudevan Deepak Kumar15-Jun-07 2:44

Vasudevan Deepak Kumar

15-Jun-07 2:44

What type of animations? There are multiple sources:

1) Animated GIFs
2) SWF (Flash Movies)
3) Javascript DHTML effects

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Re: How to add Animation ASP.Net 2.0

Not Active15-Jun-07 3:44

Not Active

15-Jun-07 3:44

This should be moved the ASP.NET forum

only two letters away from being an asset

SQL Server 2005 Try..Catch to C# Try..Catch..Finally

xyzstarr15-Jun-07 2:36

xyzstarr

15-Jun-07 2:36

Hi

Please help me. I am new to C# and SQL Server 2005, especially the exception handling side of things. Let me cut thru the chase

How do I get SQL Server 2K5 to return the details of errors that I generated with "RAISERROR" back to my C# app? When I run the application and a system error occurs, it's fine, I can catch it in my C# app, but I can't do the same with my custom errors. I hope this makes sense. Thank you.

Re: SQL Server 2005 Try..Catch to C# Try..Catch..Finally

Mali Perica15-Jun-07 3:34

Mali Perica

15-Jun-07 3:34

To cite a RAISEERROR section from SQL Server 2005 online help:

"Calling RAISERROR with severity less than 20 from inside a remote stored procedure causes a statement abort error on the remote server. A TRY…CATCH construct on the local server handles remote batch abort errors only. If a remote stored procedure calls RAISERROR with severity less than 20 and the remote stored procedure is scoped within a TRY block on the local server, RAISERROR does not cause control to pass to the CATCH block of the TRY…CATCH construct. However, RAISERROR with severity 20 or greater on the remote server breaks the connection, and execution on the local server passes to the CATCH block."

Read following sections from SQL Server 2005 online help:

-RAISEERROR
-Using RAISERROR
-Database Engine Error Severities

OR

You can return custom error codes to your C# application using output parameters in stored procedures.

Decision is up to you.

How to add TABs on an ASP.NET page

khuzwayom15-Jun-07 2:34

khuzwayom

15-Jun-07 2:34