Visual Basic

5-Sep-07 7:59

Folks, I want to declare a structure in C exactly into VB.NET. I had a problem dealing with the dimension of Char as I did not know how to declare them in VB.NET.

So can someone please give me the translated code for the structure below. Important aspect is that I will have to use the EXACT dimension to the Char array. The C structure is defined as shown below

typedef struct _IndexTransaction
{
TCHAR MsgDirPath[MAX_PATH];
DWORD dwMsgTime;
DWORD dwMsgSize;
TCHAR MsgEntryId[256];
TCHAR MsgFolderPath[256];
TCHAR MsgRecSet[32];
TCHAR MsgVolume[32];
} IndexTransaction, *pIndexTransaction;

Thanks in advance. Look forward for your responses.

Ravi

Christian Graus5-Sep-07 8:30

Christian Graus

5-Sep-07 8:30

One problem here is that TCHAR can be char or short.

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 )

Ravi Mahavrathayajula5-Sep-07 8:48

5-Sep-07 8:48

But it should be CHAR in my case with the exact dimension as specified, though it might take in less characters than the declared dimension.

Dave Kreskowiak5-Sep-07 9:05

5-Sep-07 9:05

I think you're looking for the MarshalAs attribute:

<StructLayout(LayoutKind.Sequential)> _
Public Structure MyStruct
    <MarshalAd(UnmanagedType.ByValArray, SizeConst := 260)> Public c() As Char
End Structure

...I think...

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Ravi Mahavrathayajula5-Sep-07 9:30

5-Sep-07 9:30

I never dealt with that attribute, but as you rightly said, I was finding some answers related to MarshalAs attribute. So I will try it out.

Thank you for your time friends.

Ravi Mahavrathayajula5-Sep-07 9:47

5-Sep-07 9:47

Nope buddy. It didn't seem to work. The MarshalAs field doesn't retain the dimension instead it takes the exact string length as normal.

Dave Kreskowiak5-Sep-07 10:07

5-Sep-07 10:07

This is where it helps to know EXACTLY what the API call you're using expects to see in this structure. It LOOKS like those TCHAR arrays are just being passed as if they were strings, passing just the address of the first element. So, try passing them in as strings instead:

<StructLayout(LayoutKind.Sequential)> _
Public Structure _IndexTransaction
    <MarshalAs(UnmanagedType.LPTStr, SizeConst:=260)> Public MsgEntryId As String
    Public dwMsgTime As Integer
    Public dwMsgSize As Integer
    <MarshalAs(UnmanagedType.LPTStr, SizeConst:=256)> Public MsgEntryId As String
    <MarshalAs(UnmanagedType.LPTStr, SizeConst:=256)> Public MsgEntryId As String
    <MarshalAs(UnmanagedType.LPTStr, SizeConst:=32)> Public MsgEntryId As String
    <MarshalAs(UnmanagedType.LPTStr, SizeConst:=32)> Public MsgEntryId As String
End Structure

This may or may not work. I have no idea and no way to test it. You're going to have to fiddle with it to get it to work.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

AddressOf with arguments

Amer Rehman5-Sep-07 7:58

Amer Rehman

5-Sep-07 7:58

Hi
When I use the "AddressOf" operand to call a procidure that requires some arguments, error occurs. How can I handle this problem. Error is "AddressOf operand must be the name of a method, no parentheses are required.

Code snippet is below.

Dim trThread As New Thread(AddressOf DoSomething(Arguments))

Sub DoSomething(Arguments)

'do something whatever it be
End Sub

Thanks

reman

Dave Kreskowiak5-Sep-07 8:40

5-Sep-07 8:40

You can't do that. AddressOf returns exactly that, the address of a method. Your not actually calling the method, so passing parameters is pointless.

Which version of VB.NET are you using??

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Christian Graus5-Sep-07 8:50

Christian Graus

5-Sep-07 8:50

On assumes you should just provide DoSomething and not worry about the arguments. You can only start a thread that takes no arguments, or a single argument, of type object, AFAIK.

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 )

Dave Kreskowiak5-Sep-07 8:59

5-Sep-07 8:59

Christian Graus wrote:
or a single argument, of type object, AFAIK.

You are correct sir.

Now, IIRC, that's only in .NET 2.0 and above. I think .NET 1.1- couldn't take any arguments at all and had to pick up any arguments from a third party object visible to the method being launched.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Christian Graus5-Sep-07 10:10

Christian Graus

5-Sep-07 10:10

No, I think I wrote .NET 1.1 code that multithreaded with a parameter.

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 )

Dave Kreskowiak5-Sep-07 10:37

Failed to import ActiveX component

5-Sep-07 10:37

Really?? I haven't done any threading in quite a while. I've forgotten a bunch...

I thought ThreadStart didn't take an argument, but the 2.0 ParameterizedThreadStart took an Object. Hmmm... where's my MSDN... Confused | :confused:

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Rupesh Kumar Swami5-Sep-07 1:13

Rupesh Kumar Swami

5-Sep-07 1:13

hi everyone,
when i select Window Media Player from Components tab of Choose Toolbox Items form then toolbox show Window Media Player control but when we draw window media player on form then following error occured
"Failed to Import ActiveX Control.Please ensure it is properly Registered"
i have no idea about this error . Can anyone guide me that how can i resolve this problem ?

Rupesh Kumar Swami
Software Engineer,
Integrated Solution,
Bikaner (India)

My Company

Re: Failed to import ActiveX component

DigiOz Multimedia5-Sep-07 9:40

DigiOz Multimedia

5-Sep-07 9:40

Rupesh Kumar Swami wrote:
"Failed to Import ActiveX Control.Please ensure it is properly Registered"

Have you tried to register / re-register this control using the regsvr32 command? Find the full path to the ocx in question and register it using:

<br />
Syntax<br />
regsvr32 [/u] [/s] [/n] [/i[:cmdline]] dllname<br />
<br />
Examples<br />
To register ActiveX Library:<br />
<br />
regsvr32 "C:\path_to_activex\your_ocx_name.ocx"<br />
<br />
Parameters<br />
/u : Unregisters server. <br />
<br />
/s : Specifies regsvr32 to run silently and to not display any message boxes. <br />
<br />
/n : Specifies not to call DllRegisterServer. You must use this option with /i. <br />
<br />
/i:cmdline : Calls DllInstall passing it an optional [cmdline]. When used with /u, it calls dll uninstall. <br />
<br />
dllname : Specifies the name of the dll file that will be registered. <br />
<br />
/? : Displays help at the command prompt. <br />

Pete Soheil
DigiOz Multimedia
http://www.digioz.com

Avoid Using Same Application

Trupti Mehta4-Sep-07 23:33

Trupti Mehta

4-Sep-07 23:33

Hello to all,

I understand this is not a VB question, nor is related to it in any manner. But as being a Q. based on development, I request Moderator of this forum to let the Q. by here and I may get some idea on my requirements.

I have developed an application for a client. It is a Database Driven application. The client is trying to use to same application for many other databases with same structure. How can I avoid him from making such misuse of an application. After long tries, now he has comeup with just replacing the data; data struc. is same just del. all records & insert new records & use it with another copy of the software & sell for a new purpose.

Any ideas, how can I avoid him being successful in this case. Any idea is appreciated.

Thanks

Terry

GuyThiebaut5-Sep-07 0:06

GuyThiebaut

5-Sep-07 0:06

Insert a record into one of the tables that is a marker record for you.
Then when the application kicks off get it to look for this record.
If this record is not present then lock the application.
Would this work with what you are trying?

The issue sounds like you don't want them to be able to redistribute your software - solution: use the registry, set the registry on first use, supply a key with the software.
Alternatively take the person to court for redistributing your software illegally - you did include a EULA with the software didn't you?

You always pass failure on the way to success.

Trupti Mehta5-Sep-07 2:24

Trupti Mehta

5-Sep-07 2:24

Yes, you got it right. I don't want him to reuse my application for totally free of cost. Its not fair, the though he has paid me for the application which was designed for 1 DB only, but wants to use the same for several DBs.

I had given him with the easy way only - Hard coded the connection string. Thats why he is trying to use the same DB, not to even change the name, just to change records.

He wants to use the same application for other DBs with differnt clients. For eg. a Jeweller, a Parma Supplier, a Hospital, etc. I don't think, this way the registry can be of help. As it will be distributed to differnet clients, differnt machines. So registry will be different. Please correct me, If you feel i am wrong.

I didn't include the Copyright stuff, as he will be selling on his name.

I have created a setup package, but didn't add any key.

What do you guys say? How can I avoid him from using the same application for diffeernt purposes.

GuyThiebaut wrote:
Then when the application kicks off get it to look for this record.
If this record is not present then lock the application.

That record will be visible to him in Access, though I hide it in the application stuff. Now I have to give hime v.2. So, i want to make sure, that this version he cannot use it.

Can you help me know with EULA

Thanks

Terry

Tom Deketelaere5-Sep-07 0:32

Tom Deketelaere

5-Sep-07 0:32

the simplest way (I think) is to hard code the connectionstring

a more difficult way would be to manipulate the registry (like above)

a more expensive and perhaps dangerous way would be at the start of the programme it connects to a db on you'r server (=expensive part) and check wether or not he can boot the programme
(this is just of the top of my head so don't know how it would translate into code, if it is even possible)

If my help was helpfull let me know, if not let me know why.

The only way we learn is by making mistaks.