Это единственный способ заставить это работать.
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
End Function
Public Class FenetrePrincipale
Private WithEvents _btnRechercher As New Windows.Forms.ToolStripButton("Rechercher")
Private WithEvents btnRechercherAccesBtn As New Button
Private Sub Rechercher(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRechercherAccesBtn.Click
Try
Me.Cursor = Cursors.WaitCursor
'code...
Finally
Me.Cursor = Cursors.Default
End Try
End Sub
Private Sub RechercherToolStripButton(ByVal sender As Object, ByVal e As System.EventArgs) Handles _btnRechercher.Click
Me.UseWaitCursor = True
SendMessage(Me.Handle, &H20, Me.Handle, New IntPtr(1))
Rechercher(Nothing, Nothing)
Me.UseWaitCursor = False
End Sub
End Class