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It's probably not a NULL value error, but your resulting dataset is violating the key constraints somehow. Possibly two records having the same key? That leads to another question...When you refresh the data, are you sure you're not appending a new copy of the data to the old version of the dataset?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Well, I figured this one out. Since I was retrieving data from Views, it wasn't able to determine the P-Keys on its own. I modified the Tables after data retrieval to have the Proper Key Columns on them. Afterwards, it worked great! So I guess in a sense, it was trying to append the same Records twice, and since I had Relationships setup, it was violating the Constraints. 
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I am trying to convert a VB6 project to a VB.net. My problem is that I am using an ActiveX control for charting and need to pass it an array of double. The following is an example that works well with C++ and VB6. But I need to find the dot net version of this.
C++ ActiveX function:
Short myfunction(double * data)
{
do something with data
}
VB6 function:
Dim data() as double
Dim retval as short
retval =Controlname.myfunction(data(0))
This code worked fine for VB6 to pass an array of doubles. But in VB.net only the first value in the array is passed and all the other values seem to be ignored.
If you have any suggestions I would appreciate it.
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change
retval =Controlname.myfunction(data(0))
to
retval =Controlname.myfunction(data)
You are passing only first element
Sanjay Sansanwal
www.sansanwal.com
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URL: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csref/html/vclrfusingforeachwithcollections.asp
Hi! I have created a class library in C# using IEnumerable
interface as specified in above URL, Example 2.
Now, I am iterating the items from Visual basic but it is giving
error like Object does not support this property or method while
it works fine with .net. As mentioned in URL, it should work with
the VB also.
What can be the problem?
C# code is same as in URL, Example 2.
Here is the VB code:
Dim col As New MyCollection
Dim i As Object
For Each i In col
MsgBox (i)
Next
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Dim i As Object ?
what's the reason you dim i As Object?
Dim col As MyCollection = New MyCollection ()
For Each i As Integer In col
MsgBox(i)
Next
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Hi, I am going to take MCP exam 70-306.
Is there any e-books can be downloaded ?
What sources would be useful ?
Thanks,
NUrmat
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I used the Osborne Certification Press MCAD/MCSD Book for 70-306. It helped a lot for the test and I passed with flying colors. 
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I also take MCP course too, but about windows 2000 networking. I think the best resource is Microsoft document. Try to read Microsoft press book, it contain a lot of document for people to prepare for an exam. Give you e-mail address, I will send an e-book to you. There 5 file which contain 8Mb. But each file is 2Mb max.
APO-CEDC
Save Children Norway-Cambodia Office
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Go to
www.examcram2.com
Download books for 30 days trial.
Sanjay Sansanwal
www.sansanwal.com
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Can anyone help me to add an icon on a menu item???
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Try to read the information from here[^] and here.[^] 
APO-CEDC
Save Children Norway-Cambodia Office
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Hi,
How do I link a database file .mdb to a flexgrid so that all the records in the database show up in the grid.
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You can't. Learn how to use ADO. MSFlexGridis not a "data aware" control, so you have to program everything manually.
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Thanks for your reply.
All that I want to do is to populate a grid with items from a database. I do not need to retrive items for reports.
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Try to read the information from here.[^]
APO-CEDC
Save Children Norway-Cambodia Office
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tnx a lot! one more pls..can i have sample source code on how to select the data in the database to excel using sql(or another software)?coz the codes that im doing aren't working.in excel,im using macro and pivot table to sum up all the datas automatically.but then,when it generates only the pivoted datas are there.the problem is,to get the equivalent relaycode of the relay monitoring data from database wherein the equivalent data will be put in the sheet where the pivoted datas are.Please..it was badly needed..thanks a lot!!!tc
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Hi,
I am a vb.net beginner from another country. So my english speaking is too bad.
My company is doing a project about RSA encryption in VB.net. I know a basic using about RSACryptoServiceProvider class. But i can only to use the random Public key and Private Key by RSA Object in VB.
For example,I already have a pair of keys(private key and public key).That keys are related(The keys were generate by another program).
Now I want to use my public key to encrypt my String and use my private key to decrypt my String. But I don't know how to import my key to RSA Object(Use FromXmlString/ToXmlString).
Please Help Me.(My english is too bad. Please use a simple english)
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Hi All
Im trying to connect my pocket pc 2002 to SQL 2000(SQL 8) via wi-fi with vb.net, but appar. pocket pc doesnt support ODBC? Does anyone know how i could do this?
Please help
Paul
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You would need to use RDA
Refer
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sqlce/htm/_lce_rda_intro_remote_data_access.asp
Sanjay Sansanwal
www.sansanwal.com
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Hi all,
This is for anyone who has experience with this control or is willing to help
In MSDN, there is a sample of a DataListView class, derived from ListView, that implements a data source for ListView:
http://msdn.microsoft.com/library/en-us/dnadvnet/html/vbnet08262002.asp
Which is great. The problem is this: Let's say I put a DataListView control on my form. Then I perform the following steps to add some columns:
Click on the Columns property and add some columns
Click Ok in the Columns property window when I'm done
(up to here, it's like a normal ListView)
Set the AutoDiscover property to False
Now, I re-open the Columns property window and voila! It's empty! If I look in the code, it DOES create the column objects. When I run the application, I don't see anything, as if no columns are defined. Only if the AutoDiscover property is ON, do I see the columns, data, etc.
Any idea on how to use this bloody control???
Thanks,
/=/=/=/= Sagmam =\=\=\=\
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The control code has a check wherein if AutoDiscover property is set to false then DataListView would take default column names from the datasource. To achieve this, existing columns are deleted
Check:
Public Property AutoDiscover() As Boolean
Get
Return mAutoDiscover
End Get
Set(ByVal Value As Boolean)
If mAutoDiscover = False AndAlso Value = True Then
mAutoDiscover = Value
DoAutoDiscover()
Else
mAutoDiscover = Value
If mAutoDiscover = False Then
mColumns.Clear() ' THIS LINE
End If
End If
End Set
Refer:
Auto-Discovery of Metadata
While it is nice that the end programmer can manually specify the columns to be displayed, along with the data fields to which they are bound, we should also provide a more automated alternative. Ideally, the control should be able to examine the data source and use its metadata to determine all the available data fields. Column headers can then be created for each field so the control can bind to all available fields.
Sanjay Sansanwal
www.sansanwal.com
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Thanks, I've noticed that too, only I wasn't sure why it happens in design time. I also noticed that, unlike ListView, the Designer doesn't add the "MyList.AddRange(...)" statement to the InitializeComponent method. Even if I add it myself, it doesn't help because there's another problem: you cannot have unbound columns within the list (mField = nothing).
So all in all, I wish I had a better way of doing this other than manually build my list view, but I don't. I'm just not so good with Designer-enabled user controls, so I don't know what to change in DataListView in order to make it better for my needs. The best I can do is create a DataListView of my own that is not Designer-enabled.
/=/=/=/= Sagmam =\=\=\=\
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OS: Winxp and Win2003
Visual Basic.NET 2003
MS-SQL Server 2000
hey all
I am a newbie in vb.net but i have managed to build a simple chat server in vb.net using socket and a client connecting to it made in vb6. Some of the code in the server are based on the basic samples that i get from other authors. To give you an idea, the server uses sockets, multi-threading and a database connection to MS-SQL server 2000. the off line messages, contacts lists, current status of the rooms and conference rooms are stored in the database. The client app is already done and it already meets the requirements for connecting into the server, but my server has not been optimized to do its job since i am in the code,debug and learn level, i'm still trying to make it stable. But during my testing of the server it pops an error which i haven't solved for a few weeks now especially if the server is running for a longer period of time. I have searched to a number of sites but i wouldn't give me the exact solution to my problem.
Problem:
1.)Once the server is running more than 24 hours and receives a bunch of chat messages from the client application it tends to slows down its response to the client although im testing it on a single user connection, what i did was only send a test flood of messages , then connect and disconnect a hundred times.
2.)After a hundred of test flood messages to the server and connect/disconnect session from the client, the server pops an exception error such as “operation not allowed on a non-connected sockets” but when i click ok button of the msgbox my client app sees that it is still connected to the server. The client could still send commands such as [user search but not on private and room chatting anymore] .
3.)When the server tries to save a data into the sql server it then gives me another error “the statement has been terminated”.
4.)the problem that i mostly see is during login, private and room chat, saving to database. Other strange behavior of the server is that it can still recieve a search user command and then reply for the result but when i try to do private or room chat, there it pops the error messages again and no reply to the client whatsoever.
Questions
1.)Do you think vb.net can handle more than a hundred concurrent user online or more or maybe thousand?
2.)Do you think its a good choice to have the client built in vb6 and the chat server built in vb.net ? any ideas are welcome
 Guys please i really need your help with my problems ! especially on socket and multi-threading. Any comments, suggestion or modification of the code are welcome. I have provided the server code in my site, I've omitted some of the codes and classes, to get you into the direct point, i have posted additional information of my problem in my site and some other screen shot of the error.
my site:http://www.geocities.com/jimmypearly/index.html
Thanks
Jim
PS sorry for my poor english.
-just make it tough
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jimmypearly wrote:
1.)Do you think vb.net can handle more than a hundred concurrent user online or more or maybe thousand?
Yes. It's not the language or the .NET Framework that will be limiting you. It will be the server software licensing (Windows Server that is...) and the design of your chat server.
jimmypearly wrote:
2.)Do you think its a good choice to have the client built in vb6 and the chat server built in vb.net ? any ideas are welcome
You COULD use VB6 but I wouldn't recommend it since it's essentially deprecated. Writing the clinet in VB.NET will give you the most flexibility.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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