Visual Basic

26-Nov-14 1:09

Hi
I'm having a problem in dragging and dropping multiple rows between datagrids. VB.Net can't do this by default, but i found a solution here: Drag drop multiple selected rows of datagridview with left mouse button[^]

I have put the code in a new class called DD_DataGridView.vb but I can't figure out how to use it.

I have a small test projekt, with 2 Datagridviews. Can anyone give me a hint on how to use the DD_DataGridView class from this projekt.

I'm dragging from DGV1 and dropping in DGV2.
SelectionMode is FullRowSelect

Public Class Form1
    Dim DT1 As DataTable
    Private rowIndexFromMouseDown As Int32
    Dim MouseDwn As String

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        FillDataInGrids()
    End Sub

    Private Sub FillDataInGrids()
        DT1 = New DataTable

        'Table 1 has four columns
        DT1.Columns.Add("Name", Type.GetType("System.String"))
        DT1.Columns.Add("Designation", Type.GetType("System.String"))
        DT1.Columns.Add("Department", Type.GetType("System.String"))
        DT1.Columns.Add("Salary", Type.GetType("System.String"))

        'Now Add some Rows in the first DataTable
        Dim Dr As DataRow
        For i = 1 To 40
            Dr = DT1.NewRow
            Dr("Name") = "Tom " & i.ToString("D3")
            Dr("Designation") = "Developer " & i.ToString("D3")
            Dr("Department") = "Engg " & i.ToString("D3")
            Dr("Salary") = "100" & i.ToString("D3")
            DT1.Rows.Add(Dr)
        Next i

        DGV2.Columns.Add("Name", "Name")
        DGV2.Columns.Add("Designation", "Designation")
        DGV2.Columns.Add("Department", "Department")
        DGV2.Columns.Add("Salary", "Salary")
        DGV2.Rows.Add(5)

        'Now Bind the DataGrid to datatable 1
        DGV1.DataSource = DT1
    End Sub

    Private Sub DGV1_MouseDown(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles DGV1.MouseDown
        rowIndexFromMouseDown = DGV1.HitTest(e.X, e.Y).RowIndex
        If rowIndexFromMouseDown <> -1 Then
            If Control.MouseButtons = MouseButtons.Left Then
                Dim hit As DataGridView.HitTestInfo = DGV1.HitTest(e.X, e.Y)
                DGV1.DoDragDrop(DGV1.Rows(hit.RowIndex), DragDropEffects.Copy)
                MouseDwn = DGV1.Name
            End If
        End If
    End Sub

    Private Sub DGV2_DragEnter(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragEnter
        e.Effect = DragDropEffects.Copy
    End Sub

    Private Sub DGV2_DragOver(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragOver
        e.Effect = DragDropEffects.Copy
    End Sub

    Private Sub DGV2_DragDrop(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragDrop
        Dim clientPoint As Point = DGV2.PointToClient(New Point(e.X, e.Y))
        Dim hit As DataGridView.HitTestInfo = DGV2.HitTest(clientPoint.X, clientPoint.Y)
        Dim myType As Type = GetType(DataGridViewRow)
        Dim r As DataGridViewRow = DGV1.Rows(e.Data.GetData(myType).Index)
        Dim i As Integer

        If hit.RowIndex = -1 Then
            i = DGV2.NewRowIndex
        Else
            i = hit.RowIndex
        End If
        DGV2.Rows.Insert(i)

        For j As Integer = 0 To r.Cells.Count - 1
            DGV2.Rows(i).Cells(j).Value = r.Cells(j).Value
        Next
        MouseDwn = ""
    End Sub
End Class

I guess it's pretty simple, but I have to admit that I'm more a musician than a programmer Big Grin | :-D

Regards, Tommy

Eddy Vluggen26-Nov-14 8:12

26-Nov-14 8:12

You'd copy the code into a new class. Next you'd change the "DataGridView" control to a "DD_DataGridView". The easiest way would be by rebuilding, and checking if the new control is in the toolbox. The harder way involves modifying generated code.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

tommydk27-Nov-14 7:55

27-Nov-14 7:55

Thank you for answering. I forgot to tell that the 2 grids are of type DD_DataGridView.
I guess the problem is somewhere in my own code.
I can only copy one row, even when multiple rows are dragged

Regards, Tommy

Eddy Vluggen28-Nov-14 5:26

28-Nov-14 5:26

That should have been the hardest part; if the code as is posted is correct, and nothing else changed, then the property "AllowMultiRowDrag" should only have to be set to "true", and it ought to work.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

tommydk29-Nov-14 6:19

29-Nov-14 6:19

The problem seems to be that the MouseUp event never fires in DGV1.
If I comment this line out in DGV1_MouseDown, MouseUp fires but then I can't drag and drop.

DGV1.DoDragDrop(DGV1.Rows(hit.RowIndex), DragDropEffects.Copy)

The AllowMultiRowDrag should be set to true by the MouseUp event, if more rows are selected.
So basicly it's my own code that sucks Laugh | :laugh:

Eddy Vluggen30-Nov-14 4:46

30-Nov-14 4:46

tommydk wrote:
The AllowMultiRowDrag should be set to true by the MouseUp event

Does it have to be allowed at the latest moment? Try setting it to true when the grid is constructed Smile | :)

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

tommydk12-Feb-15 10:18

12-Feb-15 10:18

I finally gave up on this, and ended with this code.
Not elegant, but it works Laugh | :laugh:

I just pick up the selected rows in DGV1_DragLeave

Public Class Form1
    Dim DT1 As DataTable
    Private rowIndexFromMouseDown As Int32
    Dim MouseDwn As String
    Dim DragList As List(Of Integer)

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        FillDataInGrids()
    End Sub

    Private Sub FillDataInGrids()
        DT1 = New DataTable

        'Table 1 has four columns
        DT1.Columns.Add("Name", Type.GetType("System.String"))
        DT1.Columns.Add("Designation", Type.GetType("System.String"))
        DT1.Columns.Add("Department", Type.GetType("System.String"))
        DT1.Columns.Add("Salary", Type.GetType("System.String"))

        'Now Add some Rows in the first DataTable
        Dim Dr As DataRow
        For i = 1 To 40
            Dr = DT1.NewRow
            Dr("Name") = "Tom " & i.ToString("D3")
            Dr("Designation") = "Developer " & i.ToString("D3")
            Dr("Department") = "Engg " & i.ToString("D3")
            Dr("Salary") = "100" & i.ToString("D3")
            DT1.Rows.Add(Dr)
        Next i

        'DGV2
        DGV2.Columns.Add("Name", "Name")
        DGV2.Columns.Add("Designation", "Designation")
        DGV2.Columns.Add("Department", "Department")
        DGV2.Columns.Add("Salary", "Salary")
        DGV2.Rows.Add(5)
        'Now Bind the DataGrid to datatable 1
        DGV1.DataSource = DT1
    End Sub

    Private Sub DGV1_MouseDown(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles DGV1.MouseDown
        rowIndexFromMouseDown = DGV1.HitTest(e.X, e.Y).RowIndex
        If rowIndexFromMouseDown <> -1 Then
            If Control.MouseButtons = MouseButtons.Left Then
                Dim hit As DataGridView.HitTestInfo = DGV1.HitTest(e.X, e.Y)
                DGV1.DoDragDrop(DGV1.Rows(hit.RowIndex), DragDropEffects.Copy)
                MouseDwn = DGV1.Name
            End If
        End If
    End Sub

    Private Sub DGV1_DragLeave(sender As System.Object, e As System.EventArgs) Handles DGV1.DragLeave
        DragList = New List(Of Integer)
        For counter = 0 To (DGV1.SelectedCells.Count - 1)
            If Not DragList.Contains(DGV1.SelectedCells(counter).RowIndex) Then DragList.Add(DGV1.SelectedCells(counter).RowIndex)
        Next
    End Sub

    Private Sub DGV2_DragEnter(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragEnter
        e.Effect = DragDropEffects.Copy
    End Sub

    Private Sub DGV2_DragOver(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragOver
        e.Effect = DragDropEffects.Copy
    End Sub

    Private Sub DGV2_DragDrop(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles DGV2.DragDrop
        Dim clientPoint As Point = DGV2.PointToClient(New Point(e.X, e.Y))
        Dim hit As DataGridView.HitTestInfo = DGV2.HitTest(clientPoint.X, clientPoint.Y)
        Dim i As Integer

        If hit.RowIndex = -1 Then
            i = DGV2.NewRowIndex
        Else
            i = hit.RowIndex
        End If

        DragList.Reverse()

        For j As Integer = 0 To DragList.Count - 1
            DGV2.Rows.Insert(i)
            For c As Int32 = 0 To DGV1.Rows(j).Cells.Count - 1
                DGV2.Rows(i).Cells(c).Value = DGV1.Rows(DragList.Item(j)).Cells(c).Value
            Next
            i = i + 1
        Next
        DragList.Clear()
        MouseDwn = ""
    End Sub
End Class

Eddy Vluggen12-Feb-15 11:37