Architecture (Windows form design)

[Roey]

I have an n-tier app that I am currently migrating from VB6 to VB.Net. My question is what is the best and most efficient way to populate fields on a form. For example if I have a customer form, should I be populating the comboxes for the Company Name, Province, and Country all at form load, or upon the respective Click event of each control.

[mutant]

I would say that popluating on form load would be better, because if you have a lot of data and you wanted to popluate it each time the control is clicked the program the program could freeze for a very short time each time you clicked the control.

[Roey]

Thanks. My next question is that when saving a record for example a customers information to a relational database I want to save a reference for the country and state, eg US = 1, and NewYork = 3. In my VB6 program I used a function called Get_ID that I created to read the primary/foreign key from the database and then loaded that value into the recordset. In .Net I am using Me.BindingContext(dsCustomer.Tables("Customer")).AddNew() to create a new rexord but am not sure how to change the value of the countries combobox from USA to its related primary key value. Hope this makes sense....

[Roey]

Here's an example in VB6 here is how I wrote data from a form to a recordset:

 

With rsCustomerDetails

!CompanyName = cboCompanyName

!Address1 = txtAddress1

!Address2 = txtAddress2

!City = txtCity

!Province = objCustomer.clsProvince_ID(cboProvince)

!Country = objCustomer.clsCountry_ID(cboCountry)

!PostCode = txtPostCode

!ContactName = txtContactName

!ContactPhone = txtContactPhone

!ContactFax = txtContactFax

!ContactEmail = txtContactEmail

!Notes = txtNotes

End With

 

In VB.Net I use:

 

cmdNew

 

Me.BindingContext(dsCustomer.Tables("Customer")).AddNew()

 

 

cmdSave

 

Me.BindingContext(Me.dsCustomer.Tables("Customer")).EndCurrentEdit()

Dim dsChanges As DataSet = dsCustomer.GetChanges()

 

 

With no control over what goes to each column in the new row.