如何将多个选定的列表框项添加到另一个列表框

Question

In my ASP.NET application I have two listboxes, say Listbox1 and Listbox2. Listbox1 having some listitems and which is in Multiple Selection Mode. If I Press the transfer button the selected items in Listbox1 should be moved to Listbox2. I have tried it for Single Selection Move and it works fine. Now I need help for multiselection.

Code for Single Selection

     strItemText = lstAvailableItems.SelectedItem.Text
     iItemCode = lstAvailableItems.SelectedValue
     lstAvailableItems.Items.Remove(New ListItem(strItemText, iItemCode))
     lstSelectedItems.Items.Add(New ListItem(strItemText, iItemCode))

Listbox image

If I press the > button single selected item will be moved from Available Items listbox to selected items list box. How to do this for multiple selection?

Answer 1

A combination of my original, and @Arman's.

    Dim lstRemoveItem As New List(Of ListItem)

    For Each li As ListItem In lstAvailableItems.Items
        If li.Selected Then
            lstRemoveItem.Add(New ListItem(li.Text, li.Value))    
            ' can't remove from the collection while looping through it       
        End If
    Next

    For Each li As ListItem In lstRemoveItem
        lstSelectedItems.Items.Add(li)       ' add to "selected" items
        lstAvailableItems.Items.Remove(li)   ' remove from the original available items
    Next

Answer 2

Use List. Iterate all items in the listbox and whatever it finds to be selected, add it to the list.

Dim lstRemoveItem As New List(Of ListItem)

For Each _item As ListItem In lstAvailableItems.Items
    If _item.Selected Then
        lstRemoveItem.Add(_item)
        'here, method to add item to the first list.
    End If
Next

For Each _item As ListItem In lstRemoveItem
    lstSelectedItems.Items.Add(_item)
Next

Not exactly what you want, but you can configure the variables easily.