VB.Net程序设计：ListBox拖动排序两个ListBox的操作

VB.Net程序设计：ListBox拖动项排序代码和两个ListBox操作

常用于：左边的listbox添加到右边的listbox。

简单代码。供自己用。

  

    'Dim _listA, _listB As New List(Of String)
    'Dim indexofsource As Integer  '//拖动的起始索引
    'Dim indexoftarget As Integer  '//拖动的结束索引

'......

Private Sub LstB_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles LstB.DragDrop
        Dim lb As ListBox = CType(sender, ListBox)
        indexoftarget = lb.IndexFromPoint(lb.PointToClient(New Point(e.X, e.Y)))
        If (indexoftarget <> ListBox.NoMatches) Then
            Dim temp As String = lb.Items(indexoftarget).ToString()
            lb.Items(indexoftarget) = lb.Items(indexofsource)
            lb.Items(indexofsource) = temp
            lb.SelectedIndex = indexoftarget
        End If
    End Sub

    Private Sub LstB_DragOver(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles LstB.DragOver
        '//拖动源和放置的目的地一定是一个ListBox
        If (e.Data.GetDataPresent(GetType(Integer)) And (CType(sender, ListBox)).Equals(Me.LstB)) Then
            e.Effect = DragDropEffects.Move
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub

    Private Sub LstB_MouseMove(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles LstB.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            indexofsource = (CType(sender, ListBox)).IndexFromPoint(e.X, e.Y)
            If (indexofsource <> ListBox.NoMatches) Then 'NoMatches=-1
                'CType(sender, ListBox).DoDragDrop(CType(sender, ListBox).Items(indexofsource).ToString(), DragDropEffects.All)
                CType(sender, ListBox).DoDragDrop(indexofsource, DragDropEffects.All)
            End If
        End If
    End Sub

    Private Sub BtnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnAdd.Click
        If Me.LstA.SelectedItems.Count = 1 Then
            If Me._listB.Contains(Me._listA.Item(Me.LstA.SelectedIndex)) = False Then
                Me._listB.Add(Me._listA.Item(Me.LstA.SelectedIndex))
                ShowListB()
            End If
        End If
    End Sub

    Private Sub BtnAddAll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnAddAll.Click
        _listB.Clear()
        For Each s As String In _listA
            _listB.Add(s)
        Next
        ShowListB()
    End Sub

    Private Sub BtnRemove_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRemove.Click
        If Me.LstB.SelectedItems.Count = 1 Then
            _listB.RemoveAt(Me.LstB.SelectedIndex)
            ShowListB()
        End If
    End Sub

    Private Sub BtnRemoveAll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRemoveAll.Click
        _listB.Clear()
        Me.LstB.Items.Clear()
    End Sub