vb.net 如何在同一数据网格视图中拖放行

How to drag and drop row within the same datagridview

提问by Troy Mitchel

In a Windows App (Visual Studio)(VB) how do you drag and drop a single row to another postition to allow for the user to re-order the row? I haven't found any worthy examples for this yet.

在 Windows 应用程序 (Visual Studio)(VB) 中，如何将单行拖放到另一个位置以允许用户重新排序该行？我还没有找到任何有价值的例子。

回答by LarsTech

Here is a vb version from this C# answer: How could I Drag and Drop DataGridView Rows under each other?

这是来自这个 C# 答案的 vb 版本：How can I Drag and Drop DataGridView Rows under each other?

The form class variables:

表单类变量：

Private fromIndex As Integer
Private dragIndex As Integer
Private dragRect As Rectangle

The drag events:

拖动事件：

Private Sub DataGridView1_DragDrop(ByVal sender As Object, _
                                   ByVal e As DragEventArgs) _
                                   Handles DataGridView1.DragDrop
  Dim p As Point = DataGridView1.PointToClient(New Point(e.X, e.Y))
  dragIndex = DataGridView1.HitTest(p.X, p.Y).RowIndex
  If (e.Effect = DragDropEffects.Move) Then
    Dim dragRow As DataGridViewRow = e.Data.GetData(GetType(DataGridViewRow))
    DataGridView1.Rows.RemoveAt(fromIndex)
    DataGridView1.Rows.Insert(dragIndex, dragRow)
  End If
End Sub

Private Sub DataGridView1_DragOver(ByVal sender As Object, _
                                   ByVal e As DragEventArgs) _
                                   Handles DataGridView1.DragOver
  e.Effect = DragDropEffects.Move
End Sub

The mouse events:

鼠标事件：

Private Sub DataGridView1_MouseDown(ByVal sender As Object, _
                                    ByVal e As MouseEventArgs) _
                                    Handles DataGridView1.MouseDown
  fromIndex = DataGridView1.HitTest(e.X, e.Y).RowIndex
  If fromIndex > -1 Then
    Dim dragSize As Size = SystemInformation.DragSize
    dragRect = New Rectangle(New Point(e.X - (dragSize.Width / 2), _
                                       e.Y - (dragSize.Height / 2)), _
                             dragSize)
  Else
    dragRect = Rectangle.Empty
  End If
End Sub

Private Sub DataGridView1_MouseMove(ByVal sender As Object, _
                                    ByVal e As MouseEventArgs) _
                                    Handles DataGridView1.MouseMove
  If (e.Button And MouseButtons.Left) = MouseButtons.Left Then
    If (dragRect <> Rectangle.Empty _
    AndAlso Not dragRect.Contains(e.X, e.Y)) Then
      DataGridView1.DoDragDrop(DataGridView1.Rows(fromIndex), _
                               DragDropEffects.Move)
    End If
  End If
End Sub

Make sure you have the grids AllowDropproperty set to true.

确保将 gridsAllowDrop属性设置为 true。

回答by Adrian LG

UPDATE:

更新：

Instead of

代替

 If dragIndex < 0 Then dragIndex = DataGridView1.RowCount - 1

change to

改成

 If dragIndex > -1 Then 
      'action if not selected in the row header and blank space
 else
      'return error if selected in the column header and blank space
 end if

then a error occurs when you drag a row to the "blank zone", if you don't believe me, you must to try it.

那么当你将一行拖到“空白区域”时会发生错误，如果你不相信我，你必须尝试一下。

the final code (Only for the part "The drag events") is this:

最终代码（仅适用于“拖动事件”部分）是这样的：

  Private Sub DataGridView1_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles DataGridView1.DragDrop
        Dim p As Point = DataGridView1.PointToClient(New Point(e.X, e.Y))
        dragIndex = DataGridView1.HitTest(p.X, p.Y).RowIndex
    'Determine if dragindex is valid row index       
    If dragIndex > -1 Then
        If (e.Effect = DragDropEffects.Move) Then
            Dim dragRow As DataGridViewRow = CType(e.Data.GetData(GetType(DataGridViewRow)), DataGridViewRow)
            DataGridView1.Rows.RemoveAt(fromIndex)
            DataGridView1.Rows.Insert(dragIndex, dragRow)
            'Add this line of code if you want to put selected rows to the rows that change
            DataGridView1.Rows(dragIndex).Selected = True
        End If 
       Else 'Do any message here if selected in column header and blank space. 
       End If
    End Sub

回答by John

Here's a Control without the mentioned bug.

这是一个没有提到的错误的控件。

Set AllowUserToOrderRowsand AllowDropto Truein the Windows Forms Designer and drag the row headers, not the content.

设置AllowUserToOrderRows并AllowDrop以True在Windows窗体设计并拖动行标题，没有内容。

Imports System.ComponentModel

Public Class BetterDataGridView
    Inherits DataGridView

    <Category("Behavior"), DefaultValue(False)>
    Public Property AllowUserToOrderRows As Boolean = False

    Protected Overrides Sub OnMouseDown(e As MouseEventArgs)
        MyBase.OnMouseDown(e)

        Dim hitInfo As HitTestInfo = HitTest(e.X, e.Y)
        If AllowUserToOrderRows AndAlso
                e.Button = MouseButtons.Left AndAlso
                hitInfo.ColumnIndex = -1 AndAlso
                ValidRow(hitInfo.RowIndex) Then
            DoDragDrop(Rows(hitInfo.RowIndex), DragDropEffects.Move)
        End If
    End Sub

    Protected Overrides Sub OnDragOver(e As DragEventArgs)
        MyBase.OnDragOver(e)

        Dim dragRow As DataGridViewRow = e.Data.GetData(GetType(DataGridViewRow))
        Dim targetIndex As Integer = GetRowIndex(e)
        e.Effect = If(ValidRowDragDrop(dragRow, targetIndex),
                      DragDropEffects.Move,
                      DragDropEffects.None)
    End Sub

    Protected Overrides Sub OnDragDrop(e As DragEventArgs)
        MyBase.OnDragDrop(e)

        Dim dragRow As DataGridViewRow = e.Data.GetData(GetType(DataGridViewRow))
        Dim targetIndex As Integer = GetRowIndex(e)

        If e.Effect = DragDropEffects.Move AndAlso ValidRowDragDrop(dragRow, targetIndex) Then
            EndEdit()

            Rows.Remove(dragRow)
            Rows.Insert(targetIndex, dragRow)

            ClearSelection()
            dragRow.Selected = True
        End If
    End Sub

    Protected Function ValidRow(rowIndex As Integer) As Boolean
        Return rowIndex >= 0 AndAlso
            rowIndex < Rows.Count - If(AllowUserToAddRows, 1, 0)
    End Function

    Protected Function GetRowIndex(e As DragEventArgs) As Integer
        Dim clientPos As Point = PointToClient(New Point(e.X, e.Y))
        Return HitTest(clientPos.X, clientPos.Y).RowIndex
    End Function

    Protected Function ValidRowDragDrop(dragRow As DataGridViewRow, targetIndex As Integer) As Boolean
        Return dragRow IsNot Nothing AndAlso
            ValidRow(targetIndex) AndAlso
            targetIndex <> dragRow.Index AndAlso
            Rows.Contains(dragRow)
    End Function
End Class

回答by Tzwenni

1.5 improvements for the event GridView.DragDrop:

1.5 事件GridView.DragDrop 的改进：

1. The first 50% improvement, To avoid the descriped error you can also use

   Private Sub DgvSearchFieldCurrent_DragDrop( _
      ByVal sender As  Object, ByVal e As DragEventArgs) _
      Handles DgvSearchFieldCurrent.DragDrop
   
   Dim LclDgv As DataGridView = CType(sender, DataGridView)
   
   If dragIndex > -1 AndAlso dragIndex < LclDgv.RowCount -1 Then
   

2. Second is to set focus to the current row and the first cell:

   LclDgv.Rows.Insert(dragIndex, dragRow)
   
   LclDgv.Rows(fromIndex).Selected = False
   LclDgv.Rows(dragIndex).Selected = True
   
   For Each C As DataGridViewColumn In LclDgv.Columns
     LclDgv(C.Index, fromIndex).Selected = False
   Next
   
   LclDgv(0, dragIndex).Selected = True
   

1. 前 50% 的改进，为了避免描述的错误，您还可以使用

   Private Sub DgvSearchFieldCurrent_DragDrop( _
      ByVal sender As  Object, ByVal e As DragEventArgs) _
      Handles DgvSearchFieldCurrent.DragDrop
   
   Dim LclDgv As DataGridView = CType(sender, DataGridView)
   
   If dragIndex > -1 AndAlso dragIndex < LclDgv.RowCount -1 Then
   

2. 其次是将焦点设置到当前行和第一个单元格：

   LclDgv.Rows.Insert(dragIndex, dragRow)
   
   LclDgv.Rows(fromIndex).Selected = False
   LclDgv.Rows(dragIndex).Selected = True
   
   For Each C As DataGridViewColumn In LclDgv.Columns
     LclDgv(C.Index, fromIndex).Selected = False
   Next
   
   LclDgv(0, dragIndex).Selected = True
   

回答by Yucel Solmaz

Thank you for everything, code working. I was getting only one error. I solved it.

谢谢你所做的一切，代码工作。我只收到一个错误。我解决了。

if the datagridview "Enable Editing" is set, you receive an error when you throw line spacing. You can try. I solved it as follows:

如果设置了 datagridview“启用编辑”，则在抛出行间距时会收到错误消息。你可以试试。我是这样解决的：

    Private Sub DataGridView1(ByVal sender As Object, ByVal e As DragEventArgs) Handles DataGridView1.DragDrop

    Dim p As Point = DataGridView1.PointToClient(New Point(e.X, e.Y))
                    dragIndex = DataGridView1.HitTest(p.X, p.Y).RowIndex
                    If (e.Effect = DragDropEffects.Move) Then
                        Dim dragRow As DataGridViewRow = CType(e.Data.GetData(GetType(DataGridViewRow)), DataGridViewRow)

                        If dragIndex = DataGridView1.RowCount - 1 Then '**ADD THIS AREA**
                            DataGridView1.Rows.RemoveAt(fromIndex)
                            DataGridView1.Rows.Insert(DataGridView1.RowCount - 1, dragRow)
                        Else
                            If dragIndex < 0 Then dragIndex = DataGridView1.RowCount - 2 '**this is important**
                            DataGridView1.Rows.RemoveAt(fromIndex)
                            DataGridView1.Rows.Insert(dragIndex, dragRow)
                        End If
                    End If
End Sub

Thanks for all other information

感谢所有其他信息