Visual Basic Discussion Boards

Johan Hakkesteegt31-Jul-07 21:56

31-Jul-07 21:56

Things to consider:
- this system would limit the amount of opened clients to the amount of PCs using the app. "Per seat" normally means per user. What if the user would like to open two clients for example to compare a live db with a test copy? Consider including a field for session amount in the table, so a user can open more than one session of the app. (a technique employed by SAP) This allows you to control that users don't simply use the same login for everybody, but will allow a user to open multiple (with a maximum number?) clients on the same machine.
- Using the workstation ID, or any other form of registration by PC (IP address, MAC, etc), will cause a lot of frustration among users, because it is very sensitive to problems with firewalls, anti virus programs, network problems, problems with an exchange server in the network, etc, etc. (trust me, this is from personal experience). Using only login IDs and some form of user management will save your customers and therefor you, a lot of grief in the short and long run. No need to predetermine the rows in the table, instead you simply limit the number of users. A user management module will also allow for easier adaptation when a customer wants to purchase additional seats in the future.
- the app will quit in unwanted ways (Murphy's Law), due to unexpected errors, power outs, etc. and entries may not get cleared from the table. Consider a way to regularly check whether sessions are still alive.
- Using this TOD (Time Of... Death, Departure, Didgeridoo?) the way you describe (ofcourse I may misunderstand you), seems superfluous to me, and I see it creating even more frustration. When a user logs in and the app closes in an unexpected way, the user would have to wait for five minutes before he can restart the app.

Hope this is of help to you,

Johan

My advice is free, and you may get what you paid for.

Re: Concurrent Licensing Scheme

dBrong1-Aug-07 6:57

dBrong

1-Aug-07 6:57

Thanks for the response.

I am thinking along simple lines that the number of rows in the table limits the number of concurrent users.

I was planning on using the computer name (that you can easily get in .net) + user_name as the key, for a row in the license table, thus, a user could have as many instances open, but just use one license.

The one issue I have is when an app aborts without clearing it's license record. This is why I was thinking of having the app update it's license record every so many minutes, with the TOD. My logon logic could determine which records were 'stale' and zero them out.

What do you think?

Connecting to Access DataBase

Assaf8231-Jul-07 13:18

Assaf82

31-Jul-07 13:18

Hello

I try to connect to Access Database, When i connec it give me this Error:

"Could not find installable ISAM"

Can someone help me???

This my connection also:
con.ConnectionString ="Provider=Microsoft.Jet.OLEDB.4.0;DataSource=E:\Documents and Settings\Assaf\Desktop\ProjectToBeSubmited\School.mdb"

Thanks in advance

Assaf

Re: Connecting to Access DataBase

Rupesh Kumar Swami31-Jul-07 20:10

Rupesh Kumar Swami

31-Jul-07 20:10

hi assaf,
every thing is correct except one

con.ConnectionString ="Provider=Microsoft.Jet.OLEDB.4.0;DataSource=E:\Documents and Settings\Assaf\Desktop\ProjectToBeSubmited\School.mdb"

in above connection string place Space between Data & Source like follwing

con.ConnectionString ="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\Documents and Settings\Assaf\Desktop\ProjectToBeSubmited\School.mdb"

hope this helps

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

Re: Connecting to Access DataBase

Assaf8231-Jul-07 23:13

Assaf82

31-Jul-07 23:13

Thank very much Rupesh

Assaf

Where has my ErrorProvider indicator gone?

penguin500031-Jul-07 12:25

penguin5000

31-Jul-07 12:25

Hi,
I'm using a variation of the following code from MSDN. I have conditions that are being met, and can display a message box to prove to myself that its reaching that point, but I'm not getting an ErrorProvider exclamation mark now that I've formatted the columns in my DataGridView to be numeric.

The MSDN Code (from http://msdn2.microsoft.com/en-us/library/0ye0dkkw.aspx) is:

MSDN Snippet:

Private Sub Customers_ColumnChanging(ByVal sender As Object, _<br />
ByVal e As System.Data.DataColumnChangeEventArgs)<br />
   ' Only check for errors in the Product column<br />
   If (e.Column.ColumnName.Equals("Product")) Then<br />
      ' Do not allow "Automobile" as a product.<br />
      If CType(e.ProposedValue, String) = "Automobile" Then<br />
         Dim badValue As Object = e.ProposedValue<br />
         e.ProposedValue = "Bad Data"<br />
         e.Row.RowError = "The Product column contians an error"<br />
         e.Row.SetColumnError(e.Column, "Product cannot be " & _<br />
         CType(badValue, String))<br />
      End If<br />
   End If<br />
End Sub

Why would formatting my columns break the ability to display the icon?

Change Hdd Name from VB.net

Aerts Nick31-Jul-07 9:52

Aerts Nick

31-Jul-07 9:52

I wont to make an application that can change driveletters(c:// to E://) but i cant find any article that describes how to do this do this. i hope you now how to do.

Re: Change Hdd Name from VB.net

Dave Kreskowiak31-Jul-07 10:17

Dave Kreskowiak

31-Jul-07 10:17

You would have to P/Invoke the Win32 API functions SetVolumeMountPoint and DeleteVolumeMountPoint to do this. Beware! You can not change the drive letter of the volume Windows is installed on. Also, it's not a good idea to change the drive letter of anything other than a removable volume. Changing the drive letter of a hard disk after application have been installed on it will result in those application breaking!

Documentation on Volume Mount Point functions[^].

A guide to posting questions on CodeProject[^]

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

Re: Change Hdd Name from VB.net

The ANZAC31-Jul-07 11:11

The ANZAC

31-Jul-07 11:11

http://www.freevbcode.com/ShowCode.Asp?ID=311

Please check out my articles:
The ANZAC's articles

Re: Change Hdd Name from VB.net

Dave Kreskowiak31-Jul-07 12:04

Dave Kreskowiak

31-Jul-07 12:04

That code changes the Volume Label, not the drive letters.

A guide to posting questions on CodeProject[^]

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

Create an Update for my project....

CCG331-Jul-07 8:32

CCG3

31-Jul-07 8:32

Hello all, I am working with VB.Net and I currently have a Setup Project that I do a Build on and install my program to different PCs. This works fine, but my question now is how can I create an 'update' to send my users instead of a full install. I also want to make sure that I don't send them the original MDB file again and overwrite the one they currently have on their machine.

Does anyone have any suggestions or know of any links explaining how to do this? I tried the Publish but it tried to install the original MDB, which would be a very bad thing.

Thanks for any advice you can offer!

Re: Create an Update for my project....

Naji El Kotob31-Jul-07 9:06

Naji El Kotob

31-Jul-07 9:06

Hi,

Try the ClickOnce deployment technique, start with this article http://msdn.microsoft.com/msdnmag/issues/04/05/ClickOnce/[^]

hope this helps Smile | :)

NajiCo http://www.InsideVB.NET[^]

It's nice 2b important, but it's more important 2b nice...

Re: Create an Update for my project.... [modified]

CCG331-Jul-07 9:48

CCG3

31-Jul-07 9:48

It looks like with ClickOnce, you have to install with a ClickOnce project, and I don't have that. I added a Setup Project to my program and I am installing using the output of Build of that Setup. So I don't think that ClickOnce is a option for me. Does anyone know of anything else I can use?

Re: Create an Update for my project....

CCG331-Jul-07 11:42

CCG3

31-Jul-07 11:42

What I have right now is the flag set to RemovePreviousVersion, and I set my MDB's Permanent property to true. And anytime I do an updated build, I have to change the Version. Then when they install, it will see the other version, un-install it, but leave the MDB alone, and then reinstall.

Does anyone else know of a better solution for updates using the Setup Project feature?

Creating database through vb.net

Kashif Sabir31-Jul-07 7:19

Kashif Sabir

31-Jul-07 7:19

i have created database in sqlserver through vb it was created successfully but when i go in enterprise manager for making query the table which were created are showing no columns i.e only All columns selection check box is there what is wrong with database?
When i execute select query the result pane showing all columns but no columns in the table structure above

MKS

Re: Creating database through vb.net

Dave Kreskowiak31-Jul-07 10:07

Dave Kreskowiak

31-Jul-07 10:07

We'd need to see the code that created the table.

A guide to posting questions on CodeProject[^]

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

Re: Creating database through vb.net

Kashif Sabir31-Aug-07 0:34

Kashif Sabir

31-Aug-07 0:34

Sorry for replying late

Following is the code for creating database please reply.
This is how i create the data base and table.

Public Function Create_UserDB(strDBFolder As String, strDBName As String, isDoubleAccounting As Boolean, isGLInclude As Boolean) As Boolean
Dim strQuery As String

Create_UserDB = False

strQuery = "CREATE DATABASE [" & strDBName & "] "
strQuery = strQuery & " ON (NAME = N'RWSDB_Data', FILENAME = N'" & strDBFolder & "\" & strDBName & ".mdf' "
strQuery = strQuery & " , SIZE = 3, FILEGROWTH = 10%) LOG "
strQuery = strQuery & " ON (NAME = N'RWSDB_Log', FILENAME = N'" & strDBFolder & "\" & strDBName & ".ldf' "
strQuery = strQuery & " , SIZE = 1, FILEGROWTH = 10%)"
ExecuteQuery strQuery

strQuery = "exec sp_dboption N'" & strDBName & "', N'autoclose', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'bulkcopy', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'trunc. log', N'true'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'torn page detection', N'true'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'read only', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'dbo use', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'single', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'autoshrink', N'true'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'ANSI null default', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'recursive triggers', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'ANSI nulls', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'concat null yields null', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'cursor close on commit', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'default to local cursor', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'quoted identifier', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'ANSI warnings', N'false'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'auto create statistics', N'true'": ExecuteQuery strQuery
strQuery = "exec sp_dboption N'" & strDBName & "', N'auto update statistics', N'true'": ExecuteQuery strQuery

strQuery = "CREATE TABLE [" & strDBName & "].[dbo].[Calendar] ("
strQuery = strQuery & " [Code] [nvarchar] (2) NOT NULL ,"
strQuery = strQuery & " [Original] [nvarchar] (4) NOT NULL ,"
strQuery = strQuery & " [Type] [nvarchar] (1) NOT NULL"
strQuery = strQuery & " ) ON [PRIMARY]"
ExecuteQuery strQuery

strQuery = "CREATE TABLE [" & strDBName & "].[dbo].[CompanyPersonalInformation] ("
strQuery = strQuery & " [Code] [nvarchar] (5) NOT NULL ,"
strQuery = strQuery & " [Ucode] [nvarchar] (5) NOT NULL ,"
strQuery = strQuery & " [GKey] [nvarchar] (100) NOT NULL ,"
strQuery = strQuery & " [CompanyName] [nvarchar] (100) NOT NULL ,"
strQuery = strQuery & " [Address] [nvarchar] (200) NOT NULL ,"
strQuery = strQuery & " [City] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [Country] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [Province] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [ZipCode] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [PhNo] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [FaxNo] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [EMail] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [WebAddrs] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [NTax] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [STax] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [FromDate] [nvarchar] (10) NOT NULL ,"
strQuery = strQuery & " [ToDate] [nvarchar] (10) NOT NULL ,"
strQuery = strQuery & " [CompanyName4Printing] [nvarchar] (100) NOT NULL ,"
strQuery = strQuery & " [STaxRate] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [IncomeTaxRate] [nvarchar] (50) NOT NULL ,"
strQuery = strQuery & " [MonthClosing] [nvarchar] (10) NOT NULL ,"
strQuery = strQuery & " [InstallationDate] [nvarchar] (10) NOT NULL ,"
strQuery = strQuery & " [ExpiryDate] [nvarchar] (10) NOT NULL ,"
strQuery = strQuery & " [Logo] [image] NOT NULL ,"
strQuery = strQuery & " [PictureSize] [numeric](18, 0) NOT NULL ,"
strQuery = strQuery & " [CreatedBy] [int] NOT NULL ,"
strQuery = strQuery & " [CreatedOn] [smalldatetime] NOT NULL ,"
strQuery = strQuery & " [UpdatedBy] [int] NOT NULL ,"
strQuery = strQuery & " [UpdatedOn] [smalldatetime]"
strQuery = strQuery & " ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]"
ExecuteQuery strQuery

Public Sub ExecuteQuery(Squery As String, Optional Action As String)
On Error GoTo errhandle

G_cn_ConnectionToMainDB.Execute Squery 'Connection to Master Database

Exit Sub
errhandle:
DisplayErrMsg (Err.Description)
' With frmStop
' .InitForm "Error Message", Err.Description, True
' .Show vbModal
' End With
End Sub

Kashif Sabir

Re: Creating database through vb.net

Paul Conrad31-Jul-07 13:15

Paul Conrad

31-Jul-07 13:15

Show the code like Dave recommended.

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

Creating a help file

dptalt31-Jul-07 6:47

dptalt

31-Jul-07 6:47

I have a Word document I would like to use as an about screen in my application. How can I show this document, while keeping all the formatting, inside my application?

Re: Creating a help file

Dave Kreskowiak31-Jul-07 7:52

Dave Kreskowiak

31-Jul-07 7:52

A Word document is way too heavy for an About box and would require that every use who uses your app have Word installed just to see your About box. A lighter, though still pretty heavy IMHO, alternative is to export the document as an HTML file and use the WebBrowser component in the Toolbox to display it.

A guide to posting questions on CodeProject[^]

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

Re: Creating a help file

dptalt31-Jul-07 9:21

dptalt

31-Jul-07 9:21

I tried using the WebBrowser component but it seems I have to hard code the entire physical path to the html file. This does not work well when installing on another computer. Do you have any good examples for this component? Thanks.

Re: Creating a help file

Dave Kreskowiak31-Jul-07 9:32

Dave Kreskowiak

31-Jul-07 9:32

dptalt wrote:
I have to hard code the entire physical path to the html file.

No, you don't. Lookup Application.StartupPath.

Dim fullPath As String = Path.Combine(Application.StartupPath, "help.html")

A guide to posting questions on CodeProject[^]

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

Re: Creating a help file

dptalt31-Jul-07 10:45

dptalt

31-Jul-07 10:45

Thanks Dave, I will try it.

is there any flex grid in vb.net

SamRST31-Jul-07 4:21

SamRST

31-Jul-07 4:21

hi my frnds,
i'm doing a vb.net windows application. here i hve a multiple entry form. is there any flex grid like vb in vb.net. how can i use it. i really fedup by searching the same..
please... please.. please....
Sigh | :sigh:

Re: is there any flex grid in vb.net

nlarson1131-Jul-07 4:25

nlarson11

31-Jul-07 4:25

if you would rather deal with flex grid you can put the grid in the vb.net project (interopt). otherwise the dategrid is the one that vb.net offers...(doesn't offer same features out of the box).

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