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Is there a Union type for VB.Net like the one in C and C++? I could really use one in my project but i dont see anything that resembles it. Any help would be aprciated
Pablo
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No. The .NET Framework doesn't directly suport unions. This includes C# and any of the other Managed languages.
You can, however, simulate one by specifying a structure layout of Explicit and giving each of your fields the appropriate offset.
<StructLayout(LayoutKind.Explicit)> _
Private Structure UnionStructure
' First set of field values
<FieldOffset(0)> Public i As Integer
<FieldOffset(4)> Public j As Integer
' Second set of field values that overlay the first set
<FieldOffset(0)> Public k As Integer
<FieldOffset(4)> Public l As Integer
End Structure
Notice the FieldOffset 's for each field specifies exactly how far from the beginning of the structure each field should be placed. Field k overlays i and l overlays j .
You can find more information here[^] on MSDN.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Thanks this will be helpfull
Pablo
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I am trying to do some serial port communication using VB.net. MSCOMM32.ocx allows me to do only ASCII characters over the COMM port. I am trying to create a datalogger for my car by reading Data from the OBD2 output. The request is querried over the COMM port but in non ASCII characters. Is there some other way that I can accomplish this task?
Thanks
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Hi,
Can someone tell me why this simple code isn't working? If the folder exists on the specified drive we should see the message "The ARCHIVE folder exists on the specified drive." If folder does NOT exists we should get the message "The ARCHIVE folderr does not exist on the specified drive."
I have ran this code to look for the folder on the "E:" drive. I received the second message. I manually added the Archive folder to the E: drive and received the same message. Why?
Code sample:
Dim fs
Const strDefaultFolder = "Archives"
Set fs = CreateObject("Scripting.FileSystemObject")
If fs.FolderExists(strDefaultFolder) Then
Msg = "The " & UCase(strDefaultFolder) & " folder exists on the specified drive."
Else
Msg = "The " & UCase(strDefaultFolder) & " does not exist on the specified drive."
MsgBox Msg, vbInformation, "test"
End If
Thank you,
Quecumber256
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You don't specify any drive in the code. You are not looking for "E:\Archives", but ".\Archives", e.g. in the working folder of the application.
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Thank you that was the problem. The VB help file is notorious for not provideing specific details in order for certain things to work.
Quecumber256
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Tell you what?
"As a programmer, it's YOUR responsibility to know how a file system works! To know how Absolute and Relative paths work! To know how to specify these things in your code and debug them!"
It's not the job of the VB documentation to teach you the basics of filesystem management. That's up to the O/S manual. And as a programmer, it's your job to know how the basic features of an operating system works before developing an application that uses them.
You sound like a lawyer who wants to put warning labels on everything to protect us from ourselves.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hi Dave,
No, I'm not a lawyer. I will admit to tunnel vision when I'm concentrating on a specific problem.
I haven't used the FileSystemObject so I make assumptions. For example when I saw this on the VB help - object.FolderExists(folderspec). I assumed it was going to look on the drive I had selected for the 'folderspec'.
If it was shown like this: object.FolderExists(Drive + folderspec) I would have known it was looking for a drive letter along with a folder name.
Thanks for the wake-up call,
Quecumber256
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Quecumber256 wrote: I assumed it was going to look on the drive I had selected for the 'folderspec'.
How do you mean that you selected a drive?
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-- modified at 9:18 Saturday 4th February, 2006
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Hello
I used a standard DriveList control to select the drive where I wanted the backup to go, and as I stated before I'm not used to the FileSystemObject. Since the drive wasn't specified in the object.FolderExists(folderspec) I assumed the FileSystemObject would already know which drive I selected.
Reading it like it stands says look and see if 'folderspec' exists. If it was written like this: object.FolderExists(Drive & folderspec) it would read to me like, "Look on the Drive variable I supplied and see if the folder exists on that drive.
A lot of the references are witten in a simular manner. The author assumes the person reading the help file will know what he means.
In the type of person who needs to know all the details on how something works.
Thank you,
Quecumber256
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If it would have been written that way, it would say that a drive specification was required, and that is not at all true.
The method uses the current folder unless an absolute path is specified, just like every other I/O method that exists. If you never used any I/O methods at all, I can understand if you don't know how that works.
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I've used I/O methods, but object oriented programming seems to add wrinkles I am not used too. There are more occasions than I care to admit where I have done something the old way like providing a drive letter and get an error because of some quirk in the object oriented syntax.
Quecumber256
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File paths have nothing to do with, nor are the rules changed by, any object oriented syntax.
The rules you violated in your folderspec pre-date DOS! They've been around for, I don't know, 30 years!
ust dropping a drive selection box on the control doesn't change the current drive, nor the current path, nor does it affect any other control. All it does is return a string with the drive letter selected!
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Is it possible to create a Property Sheet in VB6? Maybe it's so obvious that I can't find them but I don't know how to add a property sheet into my project !!!
thanks in advance,
Marc Soleda
... she said you are the perfect stranger she said baby let's keep it like this... Dire Straits
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You might want to Google for "vb6 property sheet"[^] for some examples and articles.
But, IIRC, VB6 didn't support Property Sheets. I could be wrong since it's been some 5 years since I've used VB6.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
-- modified at 13:35 Friday 3rd February, 2006
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Dave Kreskowiak wrote: You might want to Google for "vb6 property sheet"[^] for some examples and articles.
Of course I've already done it before posting it here and that's exactly what i'd found: there's no info for property sheets ...
Thanks Dave,
Marc Soleda
... she said you are the perfect stranger she said baby let's keep it like this... Dire Straits
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Hi All,
I'm trying to connect to a MySQL db using vb.net and when install the project and keep getting the following error:
ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
I've tried various options but no luck, I've tried putting file Microsoft.Data.Odbc.dll in the /bin directory, adding <%@ Import Namespace="Microsoft.Data.Odbc" %> and
<%@ Import Namespace="System.Data.Odbc" %> to the code... I've also searched the internet for about a week now and can't seem to find an answer.
Here's my connection string (the XXXXXXXXX info is correct, I've triple checked this many, many times):
strConn = "DRIVER={MySQL ODBC 3.51.12 Driver};SERVER=XXXXXXXXXX;UID=XXXXXXXXXXX;PWD=XXXXXXXXX;DATABASE=XXXXXXXXXXXXXXXxx;OPTION=3;"
Please if any body knows the answer please let me know.
-- modified at 13:15 Friday 3rd February, 2006
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1)By default mysql does not support remote access...
2) you will have to specify this in the server first, (ofcourse you will not be able to do this from a remote machine!!! unless you have remote desktop access)
3)To enable access from a client machine called nile, do the following after starting mysqld (or mysqld_safe) on the server, named delaware:
% mysql -u root -p
mysql> use mysql;
mysql> grant all privileges on *.* to usrname1@'%'
identified by 'test' with grant option;
mysql> insert into host values('nile', '%', 'Y', 'Y', 'Y', 'Y', 'Y',
'Y', 'Y', 'Y', 'Y', 'Y', 'Y', 'Y');
mysql> exit
Hope this helps you!
The user name, usrname1, and the password, test, should be replaced by the real value.
One can then run mysql on nile as follows:
% mysql --host=delaware --user=usrname1 -ptest
To restrict access to a user from a specific host, change '%' in the grant command to a valid hostname or ip address.
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hellow to all ..
i am trying to run a report that i had created in Crystal ...
i recive this message "Cannot Find KeycodeV2.dll or invaild keycode"
i had run a search at google , i had found that it has to be something related to regestring the product , so i have done so ..
but i still recive the same error ..
anyhelp ?
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Did you try looking around BusinessObjects site? I think you're looking for this[^] specific KB article.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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i had readed this artical and applied it , but i still got the same problem what could it be ?
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No idea. I've only seen the problem once and it was corrected by that article.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hi,
I want to find out least value and max value from an array variable. If variable contains Zero then it should be omitted. I hav sorted variable but i am getting value Zero.
Plz help me out.
Thanks & Regards,
Chandan Kumar.
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Post the code for your function and we'll take a look.
...Steve
"Give a man a fish and you've fed him for a day. Teach him how to fish and you've fed him for life." (Translation: I'll show you the way, but not write the code for you.) I read that somewhere once
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