|
Read the first message or two at the top of every forum.
|
|
|
|
|
Is there a way to prevent opening a second instance of the same program using the coding with VB? My program talks to a device through the usb port and I dont want the user to be able to open 2 of the same programs.
Thanks
|
|
|
|
|
I haven't got Visual Studio with me at the moment but I'm pretty sure that there is a setting in the project properties which enables you to make your application a single instance application only.
|
|
|
|
|
Thanks you very much, i should have seen that. ha.
|
|
|
|
|
You're welcome 
|
|
|
|
|
|
i am designing a database for inventory the field requirements vary a lot depending on the product nature? The fields for Digital Cameras (number of pixels, maximum zoom, type of storage) would be very different from say, Hard Disks (capacity, interface type, speed, form-factor).
i hav a tables with the shema
product
proid int
prodname varchar
proattribute xml
catid int
category
catid int
catname vachar
prodincatattribut (xsd)
how can i be to able to store the attribute for a category of product as prodincatattribut (.xsd) as define by user . and ties the proattribute(xml) to it. so that users can only put the values of this attribute
or any other better design approach will be appriciate
|
|
|
|
|
Think templates.
Each product category should get it's own attribute template. By assigning a category to a certain product, the product will also get that category's attribute template.
My advice is free, and you may get what you paid for.
|
|
|
|
|
what do you mean by attribute template
|
|
|
|
|
Ebube wrote: The fields for Digital Cameras (number of pixels, maximum zoom, type of storage) would be very different from say, Hard Disks (capacity, interface type, speed, form-factor)
Like you said, each product type (= category) has it's own attributes. So you create one xml template (xsd) per category. Then you have a choice, you can save the templates with unique names in a folder, and save the names to the Categories table, or you can try and save the entire file as a blob, or bits to the database (I would go with the first option).
Then when a new product is entered into the system, you create a new xml file based on the correct attribute template, based on the category the user chooses for the product.
My advice is free, and you may get what you paid for.
|
|
|
|
|
Hi everyone, I am doing a small chat program using vb.net forms and database instead of LAN as my academic project. I have a timer on the form which constantly checks the new messagee arrival in the database. Once someone send a message (which goes to the database), I notify the recipient and open the conversation window. It works ok for 1 to 1 chat but multiple chat session get mingled up with each other beside I am not happy with the logic as well. Is there anyone can guide me how to write a chat program which could manager multiple users/sessions.
Thanks
Nas
|
|
|
|
|
First, you don't need the database at all. What you're doing puts an ever increasing load on the database with rising number of clients since you're polling the database for new messages.
Next, all you have to do is add a conversation layer above your clients. If its the first client to hit the server, the servers creates a new conversation. The next client that hits the server can get the list of conversions to join, or create a new one.
Your chat app should be sockets based (TCP/IP) so that if one client posts a message, the server can immediately send that message to all other clients in the same conversation without having the clients polling for new messages.
|
|
|
|
|
Many thanks for your quick reply. Can you please advice me where to look for socket programming resources on the web. Thanks
|
|
|
|
|
Try here[^]
Steve Jowett
-------------------------
Real programmers don't comment their code. If it was hard to write, it should be hard to read.
|
|
|
|
|
|
Hi all...
-> i am using VS 2008 on vista 64 bit system..
-> i want to access MS Access 2007 database using oledb; but i am getting the following error...
"Microsoft.ACE.OLEDB.12.0 Provider is not registered on the local machine."
-> so how will i cope with this problem..?
J A Nasir K
|
|
|
|
|
|
I would think that your app is compiled as 64-bit. Since there are no 64-bit drivers for Access databases, you'll get this error.
Force the target to x86 and you'll limit the code to 32-bit, thus using the 32-bit drivers for Access that are installed.
|
|
|
|
|
I know this is something simple but it has been a while since i have written in Vb6 and now with vb.net I
was not sure if the same code would be accepted.
I am allowing a user to enter in a textbox numeric values
after he tabs to the next textbox I would like to format the numbers he/she entered to currency but without the "$"
so for example:
the first textbox the user would enter 12345, then he would tab to the next textbox
and the data he just entered would then we formatted to display as such: 1,234.50
Thanks for your time and help.
Again sorry that this is something a beginner should know but I just forgot.
|
|
|
|
|
PAguilar09 wrote: gain sorry that this is something a beginner should know but I just forgot.
Not at all, it's an intelligent question. The Format method on the string class lets you format a string, like string.Format( "{0:C}", textbox1.Text) wil, from memory, format a string as currency. The string.Format method is what you want to look up in general for help on how to format strings.
Christian Graus
Driven to the arms of OSX by Vista.
Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
|
|
|
|
|
ok so I am not sure if I am doing this in the right text box event.
I was trying this code in the lostfocus event but nothing worked.
Private Sub txtInitial_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtInitial.LostFocus
txtInitial.Text = String.Format("{0:C}", txtInitial.Text)
End Sub
but when i enter in lets say: 123423
and then tab to the next text box nothing changes, or should i say the data that was entered does not change to 1234.23
what am i doing wrong?
|
|
|
|
|
As far as I can see from google, that is right. Have you set a breakpoint and perhaps set an intermediate string to the value, so you can check what is and what is not working ?
Christian Graus
Driven to the arms of OSX by Vista.
Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
|
|
|
|
|
Is the lostfocus event the right one where i should be putting in the code?
when i run the program i enter in 12345 and then hit tab so the text box would lose the focus
but it still wont format
Private Sub txtInitial_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtInitial.LostFocus
txtInitial.Text = String.Format("{0:C}", txtInitial.Text)
End Sub
|
|
|
|
|
There is a FormatCurrency method that can be called to do the work for you.
It takes a number of parameters, which allow you to include things like leadin 0's, ()'s for negative numbers etc.
|
|
|
|
|
As mentioned, there is a FormatCurrency function, but if you do not what the currency symbol, the the FormatNumber may be a better option.
Also, I think I would use the Leave event of the TextBox, rather than the LostFocus event.
Steve Jowett
-------------------------
Real programmers don't comment their code. If it was hard to write, it should be hard to read.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
