目前看到三個看起來可以拿來讓我改寫的素材，但是卡在我不知道托放程式的概念，所以看不懂他在幹嘛

ListBox上下移動、拖動排序、兩個ListBox相互拖動

Dragdrop應用

[C#] 拖放應用 - ListBox

看到一個用DataGridView做拖曳排序的，和我要目標很接近，不過還是不太了解它在幹嘛，努力參透中~~~
Public Class Form1 Private SourIndex As Integer Private DragIndex As Integer Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load DataGridView1.AllowDrop = True Dim dc() As String = "A,B,C,D,E,F".Split(",") Dim i, j As Integer For i = 0 To 5 DataGridView1.Columns.Add(dc(i), dc(i)) Next For j = 0 To 11 DataGridView1.Rows.Add(New Object() {"王" + j.ToString, "身價" + (j * 10000).ToString, "", "", "", "", ""}) Next End Sub Private Sub DataGridView1_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles DataGridView1.DragDrop With sender Dim p As Point = .PointToClient(New Point(e.X, e.Y)) DragIndex = .HitTest(p.X, p.Y).RowIndex If (e.Effect = DragDropEffects.Move) Then Dim dragRow As DataGridViewRow = e.Data.GetData(GetType(DataGridViewRow)) .Rows.RemoveAt(SourIndex) .Rows.Insert(DragIndex, dragRow) End If End With End Sub Private Sub DataGridView1_DragOver(ByVal sender As Object, ByVal e As DragEventArgs) Handles DataGridView1.DragOver e.Effect = DragDropEffects.Move End Sub Private Sub DataGridView1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles DataGridView1.MouseDown SourIndex = sender.HitTest(e.X, e.Y).RowIndex End Sub Private Sub DataGridView1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles DataGridView1.MouseMove If e.Button = MouseButtons.Left Then If SourIndex > -1 Then DataGridView1.DoDragDrop(sender.Rows(SourIndex), DragDropEffects.Move) End If End Sub End Class

用2樓的爛範例改點東西就完成拖曳排序與取得起放位置的參數這兩件事，雖然還是不知道它在幹什麼......
Public Class Form1 Private SourIndex As Integer Private DragIndex As Integer Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load With ListView1 .Columns.Add("測試行") .View = View.Details .GridLines = True .MultiSelect = False .AllowDrop = True End With For i = 0 To 9 ListView1.Items.Add(i) Next End Sub Private Sub ListView1_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles ListView1.DragDrop With sender Dim p As Point = .PointToClient(New Point(e.X, e.Y)) Dim info As ListViewHitTestInfo = sender.HitTest(p.X, p.Y) DragIndex = info.Item.Index If (e.Effect = DragDropEffects.Move) Then Dim dragRow As ListViewItem = e.Data.GetData(GetType(ListViewItem)) .Items.RemoveAt(SourIndex) .Items.Insert(DragIndex, dragRow) End If End With End Sub Private Sub ListView1_DragOver(ByVal sender As Object, ByVal e As DragEventArgs) Handles ListView1.DragOver e.Effect = DragDropEffects.Move End Sub Private Sub ListView1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles ListView1.MouseDown Dim info As ListViewHitTestInfo = sender.HitTest(e.X, e.Y) SourIndex = info.Item.Index End Sub Private Sub ListView1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles ListView1.MouseMove If e.Button = MouseButtons.Left Then If SourIndex > -1 Then ListView1.DoDragDrop(sender.Items(SourIndex), DragDropEffects.Move) End If End If End Sub End Class

雖然可以完成目標了，但又出現了其他問題，如果拖曳時超過下圖紅色框框的區域就會出現錯誤，正在想有什麼方式可以解決
我也可以在創建控制項時就把物件大小調整好不讓使用者拉到不該去的區域，但是這樣只是隱藏問題，感覺不太正規，所以想找個完美的方法解決這個問題

用其他的圖床顯示不出來，還是只能用論壇提供的圖床

看到一個精簡的範例，對這托放事件有點初步的認識了

[轉貼] 最簡單 Drag Drop 範例使用
Public Class Form1 Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load '啟用拖曳 ListBox1.AllowDrop = True End Sub '觸發拖曳事件 Private Sub ListBox1_DragEnter(sender As Object, e As DragEventArgs) Handles ListBox1.DragEnter '判斷拖曳物件類型 If e.Data.GetDataPresent(DataFormats.FileDrop, False) Then '拖曳物件審核通過，允許拖曳動作 e.Effect = DragDropEffects.All End If End Sub '進行拖曳事件 Private Sub ListBox1_DragOver(sender As Object, e As DragEventArgs) Handles ListBox1.DragOver '定義寫入資料 Dim FileName() As String = e.Data.GetData(DataFormats.FileDrop) '將資料寫入ListBox For Each Index As String In FileName ListBox1.Items.Add(Index) Next End Sub End Class

這裡有講解拖放應用的一些說明，內容很詳細，可以了解一些拖放的概念
.NET中的 Drag and Drop 操作

終於寫出想要的功能了，雖然還是沒有完全的了解托放應用的觀念，但至少可以自己寫出東西了
Public Class Form1 '定義拖曳起始與結束的Item位置 Private InitialCount, FinalCount As Integer Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 'ListView屬性設定 With ListView1 .Columns.Add("Test", 100) '加入Column .AllowDrop = True '啟用拖曳 .View = View.Details '顯示模式為詳細資料 .MultiSelect = False '禁用Item多選 .GridLines = True '顯示格線 '加入Item For i = 0 To 9 .Items.Add(i) Next End With End Sub '處發條件:開始Item拖曳 Private Sub ListView1_ItemDrag(sender As Object, e As ItemDragEventArgs) Handles ListView1.ItemDrag '讀取被拖曳Item Dim SelectItem As ListViewItem = ListView1.SelectedItems.Item(0) sender.DoDragDrop(SelectItem, DragDropEffects.Move) End Sub '觸發條件:拖曳完成 Private Sub ListView1_DragDrop(sender As Object, e As DragEventArgs) Handles ListView1.DragDrop With sender '取得拖曳完成時的位置 FinalCount = .Items.IndexOf(.HitTest(.PointToClient(New Point(e.X, e.Y))).Item) '判定拖曳的資料類型是否正確 If e.Data.GetDataPresent(GetType(ListViewItem)) Then '取得被拖曳的元素 Dim InsertItem As ListViewItem = e.Data.GetData(GetType(ListViewItem)) '必須先移除被拖曳的元素才能重新加入，不然會發生錯誤 .items.Remove(InsertItem) '被拖曳Item插入位置 If FinalCount = -1 Then '拖曳至空白區，插入至最下方 .items.add(InsertItem) Else '拖曳至Item群組內，插入滑鼠放開的位置 .items.insert(FinalCount, InsertItem) End If End If End With End Sub '觸發條件：拖曳中 Private Sub ListView1_DragOver(sender As Object, e As DragEventArgs) Handles ListView1.DragOver '按著滑鼠左鍵且點選Item時才執行下列程式碼 If InitialCount <> -1 And MouseButtons = MouseButtons.Left Then '定義拖曳鼠標型態，如果沒有使用這個事件與拖曳效果無法完成拖曳 e.Effect = DragDropEffects.Move End If End Sub '觸發條件：在ListView內按下滑鼠 Private Sub ListView1_MouseDown(sender As Object, e As MouseEventArgs) Handles ListView1.MouseDown '取得滑鼠點擊時所在的Item位置 InitialCount = ListView1.Items.IndexOf(ListView1.HitTest(e.X, e.Y).Item) End Sub '觸發條件：拖曳時離開ListView Private Sub ListView1_DragLeave(sender As Object, e As EventArgs) Handles ListView1.DragLeave '刪除Item With sender '按著滑鼠左鍵且點選Item時才執行下列程式碼() If InitialCount <> -1 And MouseButtons = MouseButtons.Left And .Items.Count - 1 >= InitialCount Then .items.removeat(InitialCount) End If End With End Sub End Class

綜合您另一篇 DragLeave 的問題(http://www.blueshop.com.tw/board/FUM20050124191756KKC/BRD20180417162056AFL.html)
如果 ListView2.DragLeave 也是同 6樓 ListView1_DragLeave 一樣的話,
個人覺得可以在(第78行) .items.removeat(InitialCount) 之後,
增加一行 InitialCount = -1
這樣另一個 DragLeave 的(第77行) If InitialCount <> -1 就可排除、避免刪錯項目.
供參考.