multidimensional array using list class and dictionary - arrays

Question

//Declaration
Dim values As New List(Of Dictionary(Of String, String))()
I am trying to create a multidimensional array.
this is my code:
con.Open()
ccsfreader = ccsfcomm.ExecuteReader
ccsfreader.Read()
If ccsfreader.HasRows Then
Do
values.Add(New Dictionary(Of String, String)() From {{"CostCentre", ccsfreader.Item("CostCentre")}})
values.Add(New Dictionary(Of String, String)() From {{"ProcessDescription", ccsfreader.Item("ProcessDescription")}})
Loop While ccsfreader.Read()
End If
con.Close()
For Each value As Dictionary(Of String, String) In values
Dim CostCentre As String = value("CostCentre")
Dim ProcessDescription As String = value("ProcessDescription")
cmblaborcost.Items.Add(CostCentre)
Next
My error is:
The given key was not present in the dictionary.
i want an output like this:
1 => array(
CostCentre=>10.00
ProcessDescription=>"up"
)
2 => array(
CostCentre=>20.00
ProcessDescription=>"sided"
)
3 => array(
CostCentre=>110.00
ProcessDescription=>"cutted"
)

Answer 1

You have two dictionaries in the list. One of which contains only "CostCentre" key, and the other contains only "ProcessDescription" key. So when you try to access both keys from a dictionary, one key must be missing.
You may want to use List(Of Tuple(Of String, String)) instead of List(Of Dictionary(Of String, String)). This example works for me :
Dim values As New List(Of Tuple(Of String, String))
values.Add(Tuple.Create("a1", "a2"))
values.Add(Tuple.Create("b1", "b2"))
values.Add(Tuple.Create("c1", "c2"))
'generate array from List of Tuple'
Dim result = values.Select(Function(x) New String() {x.Item1, x.Item2}).ToArray()
For Each s As String() In result
Console.WriteLine(s(0) & ", " & s(1))
Next
And for your case, it could be something like this :
'example to add item to list'
Dim values As New List(Of Tuple(Of String, String))
......
If ccsfreader.HasRows Then
Do
'values.Add(Tuple.Create(ccsfreader.Item("CostCentre"), ccsfreader.Item("ProcessDescription"))'
values.Add(New Tuple(Of String, String)(ccsfreader.Item("CostCentre"), ccsfreader.Item("ProcessDescription")))
Loop While ccsfreader.Read()
End If
.......
'example to access item from list'
For Each value As Tuple(Of String, String) In values
Dim CostCentre As String = value.Item1
Dim ProcessDescription As String = value.Item2
cmblaborcost.Items.Add(CostCentre)
Next