Multiple rows getting selected on mouse move when I am closing ContextMenuStrip by clicking datagridview row
Note: Before looking solution for this issues you have to understand how to do drag and drop from one datagridview to another, See here http://riteshk.blogspot.com/2009/06/how-to-change-mouse-icon-when-drag_23.html
This issue is related to DataGridView DragDropEffects.Move,When you open sub menu from datagridview mouse down event and you have code to activate drag drop event too then on click of datagridview row, control in activating dagDropEffects.Move and when you move the mouse after closing the sub menu, mouse cousor having same effect (Move) and it will select multiple rows on the mouse move event.
Solution
To overcome this problem we have to ignore activating "DragDropEffects.Move" by putting some condition when sub menu get pops up
In the below code I have placed one boolean flag (isSubMenuClicked) and setting true when sub menu display otherwise its false
and check if "columnIndex > -1 and isSubMenuClicked = False" then only control should go and activate the datagridview dragdrop
DataGridView MouseDoubleClick not getting fire
Another problem here on the mouse double click "DataGridView1.DoDragDrop" should not get activate, other wise datagridview mouse double click will not get fire
Solution
To overcome this problem you have to check whether mouse button clicked once or twiced for that I have placed one condition in below code
its "If e.Clicks = 1 Then"
Source Code
Private Sub DataGridView1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles DataGridView1.MouseDown
Dim gridColumnIndex As Integer
'Get the Index of Row which is being Dragged
'We would use this Index on Drop to identify which Row was dragged and get the values from that row
If e.Button = Windows.Forms.MouseButtons.Left Then
gridColumnIndex = DataGridView1.HitTest(e.X, e.Y).RowIndex
'For Mouse Single Click Only
If e.Clicks = 1 Then
'If Grid have any row and sub menu not display
If gridColumnIndex > -1 And isSubMenuClicked = False Then
DataGridView1.DoDragDrop(gridColumnIndex, DragDropEffects.Move)
Else
DataGridView1.ClearSelection()
End If
End If
End If
Dim hitRowIndex As Integer
hitRowIndex = DataGridView1.HitTest(e.X, e.Y).RowIndex
'Open Sun Menu only on Mouse Right click and
'Avoid sub menu to display on datagridview header click
If (e.Button = Windows.Forms.MouseButtons.Right And hitRowIndex > -1) Then
ContextMenuStrip1.Show(DataGridView1, New Point(e.X, e.Y))
isSubMenuClicked = True
Else
isSubMenuClicked = False
End If
End Sub
