[2005] Mouse wheel button scroll

[dom_stapleton]

Does any one know how I can enable the user to scroll a ListView control using the mouse wheel button (ie you press the mouse wheel and you can then scroll left, right or up and down by gesturing with the mouse like in Internet Explorer)? Thanks in advance!

[bmilano]

About a year ago, I struggled with this for a while in VS 2003, and I couldn't get anywhere. If I remember correctly, the documentation said that VB accessing the mouse wheel was not supported

[dom_stapleton]

You can access the mouse button in VB 2005 as the MiddleButton.

[dom_stapleton]

Does anyone have any ideas?

[Harsh Gupta]

i dont know about .Net, but BushMobile made a similar application, using scroll button in any control, in VB6. search for it here.

maybe BM have it in his sig!!

[dom_stapleton]

Thanks for your response, Harsh Gupta. The effect I'm trying to emulate is the same as when you press the scroll wheel button in Internet Exporer and you get the following cursor:



The page is then scrolled in the a particular direction and speed depending on the location of the mouse pointer from its position when you press the wheel button.

[sparrow1]

Does any one know how I can enable the user to scroll a ListView control using the mouse wheel button (ie you press the mouse wheel and you can then scroll left, right or up and down by gesturing with the mouse like in Internet Explorer)? Thanks in advance!

Hi,

A little late for answering but it could be the solution how to use the mousewheel.
Here's a link about that;

http://msdn.microsoft.com/library/de...deltatopic.asp

Hope it helps,

sparrow1

[dom_stapleton]

Thanks for your response, sparrow1, but the effect I am trying to achieve only uses the mouse wheel to initiate the event.

What happens is the user can press the mouse wheel button (I know how to catch this), the mouse pointer then turns into the cursor shown in post #6. Then what happens is the user can navigate/scroll through the list view in the direction the user moves the mouse in relation to the postion where the user pressed the mouse wheel buton. It's incredibly hard to describe, it's best if you try it your self. If you have a mouse wheel button, position the pointer in the middle of your browser window and push it and you'll see what I mean.

[mpdeglau]

Here is what you are after. Note that you are going to have to figure out how to get the actual cursor you want....But that shouldn't be to difficult.

Private m_ScrollClicked As Boolean = False  ' if the scroll wheel is down this is set to true
    Private m_StartLocation As Point            ' this is the cursor position relative to the form when the scroll wheel is clicked
 
 
    Private Sub ListView1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListView1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Middle Then
            m_ScrollClicked = True              ' the scroll wheel has been clicked
            m_StartLocation = Windows.Forms.Cursor.Position     'set the position of where the scroll wheel was clicked
            Windows.Forms.Cursor.Current = Cursors.HSplit       'change the cursor
            Timer1.Start()                                      'star the timer
        End If
    End Sub
 
    Private Sub ListView1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListView1.MouseMove
        If m_ScrollClicked = True Then                      'the cursor kept changing back to the default
            Windows.Forms.Cursor.Current = Cursors.HSplit   'so reset it to your cursor when the mouse moves and the scroll is down
        End If
    End Sub
 
    Private Sub ListView1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListView1.MouseUp
        m_ScrollClicked = False                             'when a mouse button goes up, I assume it is the middle
        Windows.Forms.Cursor.Current = Cursors.Default      'change the cusor back to default
        Timer1.Stop()                                       'stop the timer
    End Sub
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        'The timer is what actually moves the listview.  If the current y is less than the clicked you move up
        'if the current y is greater than the clicked y you move down
        Dim i As Integer = ListView1.Items.IndexOf(ListView1.TopItem) 'gets the index of the first item that can be seen
        If m_ScrollClicked = True AndAlso Windows.Forms.Cursor.Position.Y < m_StartLocation.Y Then
            If i > 0 Then   'if there is an item above it, change the top item to that
                ListView1.TopItem = ListView1.Items.Item(i - 1)
            End If
        ElseIf m_ScrollClicked = True AndAlso Windows.Forms.Cursor.Position.Y > m_StartLocation.Y Then
            If i < ListView1.Items.Count - 1 Then   'if there is an item below it, change the item to that
                ListView1.TopItem = ListView1.Items.Item(i + 1)
            End If
        End If
    End Sub

I had the timer set to 500 milliseconds, but you will want to play around with that until you get it moving how you want it to move. Also you can use this code to increase the speed as it gets farther away from the click point, by comming up with a formula to decrease the timer interval as it gets farther away, or by increasing the number of items it moves up or down during after each interval.