.NET scroll bars-> when you scroll them to maximum position scroll.value is not max

[MrPolite]

what the heck, I dont understand this at all. I opened a blank project, added two scroll bars, each having a minimum value of 0 and a maximum value of a 100. when I run the program, and I scroll the scrollbars to the maximum value position, it appears that scrollbar.value never goes any higher than 91....

Private Sub HScrollBar1_Scroll(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles HScrollBar1.Scroll
        Me.Text = HScrollBar1.Value.ToString
    End Sub
 
    Private Sub VScrollBar1_Scroll(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ScrollEventArgs) Handles VScrollBar1.Scroll
        Me.Text = VScrollBar1.Value.ToString
    End Sub

would someone try the same thing and see is this happens to you too? because this totally doesnt make any sense to me

[dogfish227]

yep same here

[MrPolite]

uuh this is stupid, a big part of my app depends on this scrollbar controls. What the heck!

Maybe we are doing something wrong? Because it's hard to believe that these controls that have been used over years have a bug

[<ABX]

Nothing wrong with the control, it was designed this way

See why?

[pax]

Hi.

I do not agree that it was designed that way...
It seems like MS thought it was easier to write a note than to fix the bug.

Why would they design it that way anyway? I mean, what is it good for?
VB6 wasn't designed like that...

[MrPolite]

uuh huh?! what the hell? I agree with pax, I see absolutly no reason whatsoever why someone would NEED to have the scroll bars that way. I don't see any reason why anyone wouldnt want a properly working scrollbar control. Microsoft is stupid

[<ABX]

If you set the scrollbars.LargeChange Value to 1 then it will fix your problem.

[MrPolite]

Originally posted by <ABX
If you set the scrollbars.LargeChange Value to 1 then it will fix your problem.

well there is a problem with that. The LargeChange property has cetainly a purpose and setting it to 1 all the time would ruin its purpose. When the user clicks on a point on the scrollbar, he/she expects the scrollbar to "jump" to that point, and with the LargeChange set to 1 the scrollbar would only change a tad bit instead of having a large change.

I would fix it if there was a way to somehow figure out when the user clicks on the up and down arrows on the scrollbar, and when on other parts of the scrollbar, but apparently there isnt a way to do that either

[pax]

Hi MrPolite

You can use this inherited class instead of the real scrollbar.

Public Class MyScroll
    Inherits HScrollBar
 
    Dim OldMax As Integer
 
    Public Shadows Property LargeChange() As Integer
        Get
            Return MyBase.LargeChange
        End Get
        Set(ByVal Value As Integer)
            'To avoid maximum changing when largechange is changed
            OldMax = Me.Maximum
            MyBase.LargeChange = Value
            Me.Maximum = OldMax
        End Set
    End Property
    Public Shadows Property Maximum() As Integer
        Get
            'Return the REAL max
            Return MyBase.Maximum - Me.LargeChange + 1
        End Get
        Set(ByVal Value As Integer)
            'calculate 'virtual' max
            MyBase.Maximum = Value + Me.LargeChange - 1
        End Set
    End Property
 
    Public Sub New()
        'Without this the fix won't work with default maximum value
        Me.Maximum = MyBase.Maximum
    End Sub
End Class

[MrPolite]

Originally posted by pax
Hi MrPolite

You can use this inherited class instead of the real scrollbar.

Wow thank you


hmm your code is very simple and yet very complex I would never come up with something like that. Almost works perfectly fine, but still one problem: You wont get the Max value until you release the mouse button I guess I can live with this one

btw is there a way to use the old scrollbars? if I have to include a file, could someone post the file please? cuz I dont have the old VB

[pax]

Hi.

If you are thinking about the scrollbar from the "Grand Ol'e VB6" i think you would need to install the entire VB6. Maybe it's enough to regsvr32 the mscomctl32.dll, but I think there might be a license problem.

Anyway, you could also use the one in MS Forms 2.0. That would require your end user to have MS Office, but it's the only other way that I can think of.

[MrPolite]

naah
too much effort needed I'll stick with your version

[HighCommander]

Hi MrPolite

You can use this inherited class instead of the real scrollbar.

Public Class MyScroll
    Inherits HScrollBar
 
    Dim OldMax As Integer
 
    Public Shadows Property LargeChange() As Integer
        Get
            Return MyBase.LargeChange
        End Get
        Set(ByVal Value As Integer)
            'To avoid maximum changing when largechange is changed
            OldMax = Me.Maximum
            MyBase.LargeChange = Value
            Me.Maximum = OldMax
        End Set
    End Property
    Public Shadows Property Maximum() As Integer
        Get
            'Return the REAL max
            Return MyBase.Maximum - Me.LargeChange - Me.Minimum  + 1
        End Get
        Set(ByVal Value As Integer)
            'calculate 'virtual' max
            MyBase.Maximum = Value + Me.LargeChange + Me.Minimum - 1
        End Set
    End Property
 
    Public Sub New()
        'Without this the fix won't work with default maximum value
        Me.Maximum = MyBase.Maximum
    End Sub
End Class

Granted this post is old, but it is still relevant. My scroll bar is 1 based and not 0 based.
I was having a problem when I scrolled to max, It would get "Stuck" there until I altered the scroll.value.
So, I made a small tweak to your code, because not ever scrollbar is going to be zero based. So in the get and set I added Me.Minimum to the calculations.
Now even if Minimum is 5, the scrollbar will scroll properly. Thanks for a nice starting point.

And for the coder who was mentioning that the max isn't actually reached until you release the mouse button, It is that way on a standard scrollbar as well.

I always set my Minimum first, so I didn't see the need for shadowing that property.