Visual Basic

Re: Find mac address on all computers on network

16-Dec-05 15:09

Well, you have one problem. You can't get the MAC address of any NIC that's not on the same subnet that your app is running on. ARP requests won't hop routers.

The only way around this is to use WMI and query each Windows machine for it's list of network adapter configurations (Win32_NetworkAdapterConfiguration). This won't work with non-windows machines and will have problems with Windows versions below NT4 SP3.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

GregRH19-Dec-05 5:15

GregRH

19-Dec-05 5:15

Thanks for responding.

That is a good point.

Well for now lets say I just want to look at a subnet.
How could I do that in VB.net?

If I can get a list of the IP address I can query them
for their mac address.

What I am tring to do is look for a specific mac address.
This address will have the same first 3 numbers. These
are network devices that won't be attached to a computer.

Any help would great.

Have a problem Saving changes to database

jbeggie16-Dec-05 8:33

jbeggie

16-Dec-05 8:33

I need help. I want to save changes made to my data set through a datagrid to the main database. here is my code.

If myDataSet.HasChanges Then
myDataAdapter.Update(myDataSet.Tables("myDataTable"))
End If

each time I run it, I get the error:

"An unhandled exception of type 'System.InvalidOperationException' occurred in system.data.dll

Additional information: Update requires a valid UpdateCommand when passed DataRow collection with modified rows."

jbeggie

Re: Have a problem Saving changes to database

Dave Kreskowiak16-Dec-05 9:23

Re: Designer Generated Code

16-Dec-05 9:23

How are you building your DataAdapater object. It looks like your missing the SqlCommand that actually updates the database. Just grabbing a dataset from a Sql SELECT statement will not let you write the changes back to the database. You need to supply the UPDATE commands to do it, or supply the DataAdapter with the SqlCommandBuilder object that uses the SELECT command to build the UPDATE, INSERT, and DELETE commands for you.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Designer Generated Code

Tainter16-Dec-05 7:22

Tainter

16-Dec-05 7:22

Unfortunately I don't have the advantage of working in .NET yet...my question is this...In VB6 is there anyway to see the Windows Generated Designer code like you can in .NET?

I need to pass a parameter into a new form that Im creating and would like to modify the constructor...anyone have ideas on this?

Thanks

Jerami Tainter
Computer Programmer
jtainter@gmail.com

Dave Kreskowiak16-Dec-05 9:20

Re: Designer Generated Code

16-Dec-05 9:20

There is no Designer generated code like there is in .NET. The way I used to do it was to put a public method into the new form's code and call that to init the form after creating an instance of it.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Joshua Quick16-Dec-05 9:46

Joshua Quick

16-Dec-05 9:46

Tainter wrote:
In VB6 is there anyway to see the Windows Generated Designer code like you can in .NET?

If you open your *.frm file in Notepad, then you can see its form configuration at the top of the file. But this isn't code. You really shouldn't be messing with this config.

Tainter wrote:
I need to pass a parameter into a new form that Im creating and would like to modify the constructor...anyone have ideas on this?

VB6 forms don't have constructors. The next best thing that you've got is the FormLoad event, but you can't pass anything to it. You'll need to create a Function/Subroutine to pass in data to be stored in member variables before showing your form.

Re: Designer Generated Code

Tainter16-Dec-05 9:52

Tainter

16-Dec-05 9:52

Thanks for the input guys

Jerami Tainter
Computer Programmer
jtainter@gmail.com

calling .NET virtual method from VB6

IsaacB16-Dec-05 6:46

IsaacB

16-Dec-05 6:46

Hi, there is a method in Managed C++ defined as

virtual void CargarXMLEntrada(String *inputXMLPath) = 0;

I'm new to interop and havent been able to find the way to override that method in VB6 or if interop is the way to go, anybody knows how can this method be overriden?

Thanks in advance
Isaac B

Convert BMP to black & white

thrakazog16-Dec-05 6:37

thrakazog

16-Dec-05 6:37

I have a 32bit BMP that I am trying to save as black and white. My best guess was that I could use the Clone method. Clone should allow me to set the pixel format as follows:

<br />
Dim bmpBlackWhite As Bitmap<br />
Dim bmpColor As Bitmap<br />
<br />
bmpColor= New Bitmap(100, 100 , PixelFormat.Format32bppRgb)<br />
bmpBlackWhite = New Bitmap(100, 100 ,  PixelFormat.Format1bppIndexed)<br />
<br />
bmpColor = GetColorImage<br />
<br />
bmpBlackWhite = bmpColor.Clone(New Rectangle(0, 0, 100, 100), PixelFormat.Format1bppIndexed)

When I run this code I get a "Out of memory error" on the Clone command.

Does anyone know either how I can fix this code, or have another method that can save a color BMP as black and white??

Thanks.

Re: Convert BMP to black &amp; white

Dave Kreskowiak16-Dec-05 7:04

SQL Query (VB6 & MS Access)

16-Dec-05 7:04

Yeah, you can't convert any of the RGB formats to an Indexed format.
You might want to look at this[^] article by Christian Graus.

The techniques can't be ported to VB.NET because they use unsafe code, but you can still use them if you put them in a library and call the methods from VB.NET.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

mellvincent16-Dec-05 4:18

mellvincent

16-Dec-05 4:18

I have a table with 2 fields: ProductCode(Text) and InventoryNo(Int). I'd like to display the largest integer in InventoryNo field that has the same ProductCode. my SQL query is :

SELECT MAX(InventoryNo) FROM StockTable WHERE ProductCode = '&txtprdcode.Text&'

The problem is, the outcome I got was the largest integer regardless of its ProductCode (The output was more like the largest integer in InventoryNo Column).

What seems to be the problem?

TQ

Re: SQL Query (VB6 &amp;amp; MS Access)

albCode16-Dec-05 4:52

albCode

16-Dec-05 4:52

SELECT MAX(InventoryNo) FROM StockTable WHERE ProductCode = & "'"&txtprdcode.Text&"'"

if InventoryNo = ProductCode then
'some code
else
'mismatch
endif

Hope this helps,

-- modified at 10:53 Friday 16th December, 2005

App to Authenticate a User

bduboftexas16-Dec-05 4:14

bduboftexas

16-Dec-05 4:14

We're needing to embed into a program - a piece that will force the user to log in again - this is necessary for FDA Part 11 - and then have the app verify the credentials which were just entered against the active directory. Unfortunately the app we have isn't er/esig capable - so we're having to customize it - but so far, haven't found anything we could use and not have to write from scratch...

anybody know of anything useable?

Re: App to Authenticate a User

Joshua Quick16-Dec-05 9:55

Joshua Quick

16-Dec-05 9:55

I have to write app's that are 21 CFR part 11 compliant too.
(To everyone else, CFR stands for Compliance to Federal Regulations.)

I don't think Windows does enough to satisfy this. I (and my competitors) typically have to create apps having their own user accounts and login handling in order to satisfy the FDA's requirments. Requirements such as password aging, auto-logout, user authentication, and audit trails. Windows won't do those last 2 bits for you.

USB

Sushmadm16-Dec-05 2:19

16-Dec-05 2:19

Hi all,

Can someone tell me how to use USB port for communication in VB?

Thanks in advance,
sushma

Dave Kreskowiak16-Dec-05 4:44

16-Dec-05 4:44

That depends entirely on the device you want to talk to. There is no such thing as "generic" code that lets you talk to any device on USB. Most of teh time, this will require lower level calls to the devices drivers.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Sushmadm18-Dec-05 18:29

18-Dec-05 18:29

Thanx so much for responding to my post.I must establish communication between two PCs through USB port.I have no idea of how to go about it.Please tell me what are the pre-requisits for programming a USB port.

Thanx again,
sushma

Dave Kreskowiak19-Dec-05 1:47

19-Dec-05 1:47

First, you need a special USB host-to-host cable to connect them. Using any old USB cable you get for connecting devices to the PC can blow the ports on both PC's. After that, you install the drivers and end up with a 2 machine network that works over TCP/IP. There's nothing you do in your source code to specially handle USB networks. To your code, it looks just like any other TCP/IP network.

USB PC to PC Network Cable TCP/IP[^]

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

-- modified at 7:48 Monday 19th December, 2005

Sushmadm19-Dec-05 21:36

19-Dec-05 21:36

Hi Dave,

I got few modules(hidinterface,osinterface,USBmAPI) and DLLs(USBm.dll,APIGID32.DLL).I got these from intel site(u may be knowing about these). Cant i work on my program using these?

Dave Kreskowiak20-Dec-05 2:41

20-Dec-05 2:41

Why? So you can take 10 times longer to write your app? Do you have any idea how USB works? How to enumerate devices on the bus, select a device, communicate with another host on the bus? This is very specialized stuff and there is not alot of documentation out there on how to do it. You won't find any code in VB.NET that show you how to do this.

You're re-inventing the wheel when you don't have to...

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Sushmadm20-Dec-05 17:36

20-Dec-05 17:36

Thanks so much for ur suggestion.Please tell me which driver software i must install?What is the cost of the driver software?What are the necessary steps to be followed after installing that?.I have worked on RS232 serial communication using MScomm activex control in VB.I just want to know whether i will be able to implement the same with USB? Will the driver software be flexible like an activex control?. Initially i will be working on PC to PC communication.Later on i must write program for establishing communication between PC and Hand Held Controller.Please do help me with this, i will be very greatful to u.

Thanx again,
Sushma

Dave Kreskowiak20-Dec-05 18:40