Drag and Drop between DGV's - how to determine the source DGV?

[Tim_8]

Hi,
I have a DGV (dgvListOfJobs), populated from an SQL database to show the user a list of 'jobs' (i.e. rows). I also show 7 other DGV's (dgvMonday, dgvTuesday, etc) for each day of the week so the user can drag a job from the list and drop it onto a particular day. Once dropped I update the SQL record with a corresponding date. The user can also drag and drop between days, or drag a job back to the main job list to remove it from the week's jobs (i.e. the SQL writes a null to the date field). This all works fine.
However - if a user picks up a job and drops it onto the same dgv, it still triggers the 'dropped' event and writes a date, or a null, to the SQL. I want to have a check at the start of the 'drop' procedure so if the job was picked up and dropped back into the same DGV, the drop event quits straight away without re-writing the SQL.

I could read the SQL to see if the date matched but this involves an EXTRA sql access and I am trying to speed up the process by removing an SQL event if at all possible.

After Googling for a solution I think it may be something to do with 'DirectCast' but I can only get this to report 'DataGridView' as the source, not the name of a specific dgv - 'dgvThursday' for example.

I notice the 'DragDrop' event paramters include a 'sender' object but cannot work out how to utilise this (and even if it will help!)

[xrjf]

dim dgv as datagridview = DirectCast(sender,DatagridView)
if dgv.name = "..." then

[Tim_8]

Thanks xrj - sorry about the delay replying. i have put this code into the 'Handles dgvListOfJobs.DragDrop'

        Dim mySourceDGV As DataGridView = DirectCast(sender, DataGridView)
        MessageBox.Show("Source = " & mySourceDGV.Name.ToString)

However the messagebox only ever shows 'dgvListOfJobs' as the source, even if I have dragged and dropped a job from 'Monday' for example. Do I need to set something up in the initial 'MouseDown' event ie. when I initially pick up the job?

[xrjf]

On the mouse down event for each source, while initiating the drag, you may set a flag IsMouseDown with a value indicating which is the source. If the mouse down event occurs in let's say DataGridView1, then set IsMouseDown=srcIsNum1. In case the dragging starts with a mouse down event on a cell (or row, column, ...) of DataGridView2, set IsMouseDown=srcIsNum2. Of course flag IsMouseDown can be a class instance and contain much more information; not only the source, but the row, column, or any required data.

    Enum mouseDwn
        srcIsNum1
        srcIsNum2
    End Enum
    Dim IsMouseDown As mouseDwn

[xrjf]

For example:

    Enum mouseDwn
        none = 0
        srcIsNum1
        srcIsNum2
    End Enum
    Dim IsMouseDown As mouseDwn = mouseDwn.none
    Private Sub DataGridView1_CellMouseDown(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseDown
        IsMouseDown = mouseDwn.srcIsNum1
    End Sub
    Private Sub DataGridView2_CellMouseDown(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView2.CellMouseDown
        IsMouseDown = mouseDwn.srcIsNum2
    End Sub
    Private Sub DataGridView2_CellMouseMove(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView2.CellMouseMove
        If IsMouseDown = mouseDwn.srcIsNum2 Then
            With DataGridView2
                .DoDragDrop(CStr(.Rows(e.RowIndex).Cells(e.ColumnIndex).Value), DragDropEffects.Copy)
                IsMouseDown = mouseDwn.none
            End With
        End If
    End Sub
    Private Sub DataGridView1_CellMouseMove(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseMove
        If IsMouseDown = mouseDwn.srcIsNum1 Then
            With DataGridView1
                .DoDragDrop(CStr(.Rows(e.RowIndex).Cells(e.ColumnIndex).Value), DragDropEffects.Copy)
                IsMouseDown = mouseDwn.none
            End With
        End If
    End Sub
    Private Sub DataGridView1_DragEnter(sender As Object, e As System.Windows.Forms.DragEventArgs) Handles DataGridView1.DragEnter
        If e.Data.GetDataPresent(DataFormats.Text) AndAlso _
        IsMouseDown = mouseDwn.srcIsNum2 Then
            e.Effect = DragDropEffects.Copy
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub
    Private Sub DataGridView2_DragEnter(sender As Object, e As System.Windows.Forms.DragEventArgs) Handles DataGridView2.DragEnter
        If e.Data.GetDataPresent(DataFormats.Text) AndAlso _
        IsMouseDown = mouseDwn.srcIsNum1 Then
            e.Effect = DragDropEffects.Copy
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub
    Private Sub DataGridView1_DragDrop(sender As Object, e As System.Windows.Forms.DragEventArgs) Handles DataGridView1.DragDrop
        Try
            Dim row, col As Integer
            getRowAndColumn(sender, row, col, e)
            DataGridView1.Rows(row).Cells(col).Value = e.Data.GetData(DataFormats.Text)
        Catch ex As Exception
        End Try
    End Sub
    Private Sub DataGridView2_DragDrop(sender As Object, e As System.Windows.Forms.DragEventArgs) Handles DataGridView2.DragDrop
        Try
            Dim row, col As Integer
            getRowAndColumn(sender, row, col, e)
            DataGridView2.Rows(row).Cells(col).Value = e.Data.GetData(DataFormats.Text)
        Catch ex As Exception
        End Try
    End Sub
    Sub getRowAndColumn(sender As Object, ByRef row As Int32, ByRef col As Int32, e As System.Windows.Forms.DragEventArgs)
        With DataGridView1
            Dim grvScreenLocation As Point = sender.PointToScreen(sender.Location)
            Dim tempX As Integer = DataGridView.MousePosition.X - grvScreenLocation.X + sender.Left
            Dim tempY As Integer = DataGridView.MousePosition.Y - grvScreenLocation.Y + sender.Top
            Dim hit As DataGridView.HitTestInfo = sender.HitTest(tempX, tempY)
            row = hit.RowIndex
            col = hit.ColumnIndex
            .Rows(row).Cells(col).Value = e.Data.GetData(DataFormats.Text)
        End With
    End Sub