Question ArgumentNullException Message : please help

armand21

Member
Joined
Jan 9, 2010
Messages
12
Location
casablanca
Programming Experience
3-5
Hi everyone

I have coded the following class then when i m trying to compile i m receiving the following error message in the FillList procedure at the following line : LstCooking.Items.Add(ck)


"ArgumentNullException was Unhandled "


Please help

Thanks and regards


Armand



Imports System.IO
Imports System.IO.File

Public Class Form1

Private ReadOnly mFilePath As String = "..\..\cooking.txt"
Private allcookings() As Cooking

Private Sub Form1_Load() Handles MyBase.Load

GetFile()
FillList()
End Sub

Private Sub FillList()

LstCooking.Items.Clear()
For Each ck As Cooking In allcookings
LstCooking.Items.Add(ck) <--------------
Next
End Sub

Public Function GetFile() As Boolean
' Read the data file, try to find the account ID.
' If found, read the account name and balance and
' return True. If not found, return false.
' An array is used to hold the workshops, since

'not all students may
' be familiar with collections.

Dim infile As StreamReader = Nothing
LblResult.Text = String.Empty
Try
infile = OpenText(mFilePath)
Dim numVals As Integer = CInt(infile.ReadLine)
ReDim allcookings(numVals - 1)

For i As Integer = 0 To numVals - 1
Dim entireLine As String = infile.ReadLine()
Dim fields() As String = entireLine.Split("\"c)
Dim cook As New Cooking
cook.mcategory = CType(fields(0), Cooking.CookingType)
cook.CookingTime = CInt(fields(1))
cook.mcost = CDbl(fields(2))
cook.mtitle = fields(3)
allcookings(i) = cook
Next
Return True
Catch ex As Exception
LblResult.Text = ex.Message
Return False
Finally
If infile IsNot Nothing Then

infile.Close()
End If
End Try
Return False
End Function

Private Sub btnDetails_Click() Handles BtnDetails.Click

Dim index As Integer = LstCooking.SelectedIndex
If index = -1 Then
LblResult.Text = "Please select a cooking"
Return
Else
LblResult.Text = String.Empty
End If

Dim frm As New DetailsForm
frm.onecooking = allcookings(index)
frm.ShowDialog()
FillList()
End Sub


End Class


PS

The arrow was added just to locate the line that s raising the error message

Once again thanks for any help
 
allcookings array contains one of more null references (Nothing), debug the source of that.
 
Thanks John But....

Hi John

Thanks for taking your time to answer me.

Second though i guess the trouble comes from GetFILE function especially this bunch of code


Try
infile = OpenText(mFilePath)
Dim numVals As Integer = CInt(infile.ReadLine)
ReDim allcookings(numVals - 1)

For i As Integer = 0 To numVals - 1
Dim entireLine As String = infile.ReadLine()
Dim fields() As String = entireLine.Split("\"c)
Dim cook As New Cooking
cook.mcategory = CType(fields(0), Cooking.CookingType)
cook.CookingTime = CInt(fields(1))
cook.mcost = CDbl(fields(2))
cook.mtitle = fields(3)
allcookings(i) = cook
Next
Return True
Catch ex As Exception
LblResult.Text = ex.Message
Return False
Finally
If infile IsNot Nothing Then

infile.Close()
End If
End Try


I believe in that code nothing is allocate to allcooking (that s why the ArgumentNULLException is raised ) i dont find the place but i m thinking about how to solve it
 
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