Structure cannot be indexed because it has no default value

Hi Guys,

Can anyone tell me what I'm missing here:

Code:

---


Structure EmployeeData
    Dim EmployeeName As String
    Dim JobTitle As String
    Dim TaxRate As Single
End Structure

 Public Sub OpenEmployeeFile(ByVal ViewForm As Object, ByVal ListBox As Object)

        Dim EmployeeList As EmployeeData = Nothing
        nEmployees = 0
        ViewForm.EmployeeListBox.Items.Clear()

        FileOpen(1, "EmployeeData.epc", OpenMode.Binary, OpenAccess.Read)

        While Not EOF(1)
            FileGet(1, EmployeeList)
            EmployeeArray(nEmployees) = EmployeeList
            ViewForm.ListBox.Items.Add(EmployeeList.EmployeeName)

        End While
    End Sub

---

you're using pre .net code there. there are newer more efficient ways to do that.

how are you saving "EmployeeData.epc"? it could be done with binary serialization in a few lines of code + deserialized with another few lines of code.

Thanks for the reply. I'm creating a PAYE calculator as uni coursework.

Basically what I want to do is have a file which stores Employee Name, Job Title and tax rate which can be read into the program to fill combo boxes etc.

I'm then going to have another file with Job Title and Paye Rate.

I then want to be able to read them into the program and populate various text, combo, labels and listviews.

For example, my main page has a combo box for selecting the employee. When I select an employee I want to fill in Job title, tax rate and paye rate. Once done I will use the data in those fieilds to calculate monthly paye.

I'm going to have a separate form to edit the two text files.

This is just a uni program so I'm not too worried about people being able to read the files in a text editor etc.

try this:

first declare the structure + bindinglist:

vb Code:

<System.Serializable()> _
Private Structure EmployeeData
    Dim EmployeeName As String
    Dim JobTitle As String
    Dim TaxRate As Single
    Public Overrides Function ToString() As String
        Return EmployeeName
    End Function
End Structure
 
Private EmployeeList As New System.ComponentModel.BindingList(Of EmployeeData)

then load the bindinglist:

vb Code:

EmployeeList.Add(New EmployeeData With {.EmployeeName = "john", .JobTitle = "vocals", .TaxRate = 17.5})
EmployeeList.Add(New EmployeeData With {.EmployeeName = "paul", .JobTitle = "bass/vocals", .TaxRate = 17.5})
EmployeeList.Add(New EmployeeData With {.EmployeeName = "george", .JobTitle = "guitar", .TaxRate = 17.5})
EmployeeList.Add(New EmployeeData With {.EmployeeName = "ringo", .JobTitle = "drums", .TaxRate = 17.5})

serialize (save) the bindinglist:

vb Code:

Dim formatter As New Runtime.Serialization.Formatters.Binary.BinaryFormatter
Dim fs As New IO.FileStream("test.bin", IO.FileMode.Create)
formatter.Serialize(fs, EmployeeList)
fs.Close()

then to deserialize (read):

vb Code:

EmployeeList = New System.ComponentModel.BindingList(Of EmployeeData)
formatter = New Runtime.Serialization.Formatters.Binary.BinaryFormatter
Dim fs As New IO.FileStream("test.bin", IO.FileMode.Open)
EmployeeList = DirectCast(formatter.Deserialize(fs), System.ComponentModel.BindingList(Of EmployeeData))
fs.Close()
 
ListBox1.DataSource = EmployeeList

Thanks for the help. With a bit of extra help from my boss at work I'm sort of getting use to using the streamreader. However, back to my initial query, I found that I still cannot use a structure as it keeps telling me I have no defaut structure.

If I use the write code and the structure withiun the call of a form it works. When I try and move the code to a module, I get the above error. Why is it that the above error occurs when I try and use the structure in a module as apposed to a form? Is there something I dont know about the use of structures in a module and how do I give it a "default value"?

Tell a lie. I just added the stucture and all code to the main form and I still get an error about the default values. Help!