CODEWITHSUNDEEP
vb.netdictionaryforeach
Dipendra Shekhawat
Dipendra Shekhawat

Reputation: 55

Removing item from Dictionary in VB.net

I have something like this:

    Public Shared Property PinnedChannelConnectionIds() As Dictionary(Of Integer, List(Of String))
    Get
        If _pinnedChannelConnectionIds Is Nothing Then
            Return New Dictionary(Of Integer, List(Of String))
        Else
            Return _pinnedChannelConnectionIds
        End If
    End Get
    Set(value As Dictionary(Of Integer, List(Of String)))
        _pinnedChannelConnectionIds = value
    End Set
End Property

And then, have some data in dictionary as :

1, {"c1","c2", "c3"}
2, {"c2","c4", "c6"}
3, {"c3","c5", "c1"}
4, {"c4","c3", "c6"}

So to remove a specific item. Let say "c2" from the above dictionary. I am doing like this:

For Each channelKeyValuePair As KeyValuePair(Of Integer, List(Of String)) In Channel.PinnedChannelConnectionIds
            For Each item As String In channelKeyValuePair.Value.ToList()
                If (item.Equals("c2")) Then
                    Channel.PinnedChannelConnectionIds(channelKeyValuePair.Key).Remove(item)
                End If
            Next
        Next

But it throws error : Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.

Can anyone please help me out. Thanks in advance!!

Upvotes: 2

Views: 6349

Answers (1)

Brian Hooper
Brian Hooper

Reputation: 22054

I'd suggest something like 

For Each channelKeyValuePair As KeyValuePair(Of Integer, List(Of String)) In Channel.PinnedChannelConnectionIds
    channelKeyValuePair.Value.RemoveAll(Function(x) x = "C2")
Next

might work. There's no need to iterate over the list elements to find and remove them and it can cause difficulties of the sort you are experiencing.

Upvotes: 1

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