将列表框项目分为两部分，然后将其粘贴到两个列表框中

Question

so the code i ma trying to run is:

 Private Sub ListBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListBox1.SelectedIndexChanged
        Dim size2 As Integer = ListBox1.Items.Count / 2
        Dim size1 As Integer = ListBox1.Items.Count - size2

        ListBox2.Items.AddRange(ListBox1.Items.GetRange(0, size1))
        ListBox3.Items.AddRange(ListBox1.Items.GetRange(size1, size2))
    End Sub

i have imported System.Linq but error occers getrange is not a member of listbox.objectcollection

Answer 1

There's no such thing as a GetRange() extension in Linq. The List(Of T) class has such a method , however. So you could use the Cast(Of TResult) extension to convert the collection into an IEnumerable(Of T) , then use the ToList() extension to convert that into a List(Of T) :

Dim ItemsList As List(Of Object) = ListBox1.Items.Cast(Of Object).ToList()

ListBox2.Items.AddRange(ItemsList.GetRange(0, size1))
ListBox3.Items.AddRange(ItemsList.GetRange(size1, size2))