Question

Here is the situation:

I am trying to control flowLayoutControl’s scroll bar from devexpress controls VerticalScroll.

Now – flowLayoutControl with autoscroll = true. I added a new verticalscroll control and dock it to Right. So now the Devexpress Vertical Scroll control is right on top of FlowLayout scrollbar.

Also the FlowLayoutPanel vertical scroll does not hide when following code is run:

    spotWinFlowLayout1.VerticalScroll.Visible = false

I have setup the following event handlers:

    private void spotWinFlowLayout1_Resize(object sender, EventArgs e)
    {
        SetupVerticalScrollBar();
    }        

    private void SetupVerticalScrollBar()
    {
        vScrollBar1.Minimum = spotWinFlowLayout1.VerticalScroll.Minimum;
        vScrollBar1.Maximum = spotWinFlowLayout1.VerticalScroll.Maximum;
        vScrollBar1.LargeChange = spotWinFlowLayout1.VerticalScroll.LargeChange;
        vScrollBar1.SmallChange = spotWinFlowLayout1.VerticalScroll.SmallChange;            
    }

    private void vScrollBar1_Scroll(object sender, ScrollEventArgs e)
    {
        spotWinFlowLayout1.VerticalScroll.Value = e.NewValue;
    }

Everything is working fine except when on form Load there is already a scrollbar on flowLayoutControl,
spotWinFlowLayout1.VerticalScroll.XXX properties not set yet. So both the scrollbars are out of Sync. But as soon as I resize the form both get Sync.

So when is scrollbar for the FlowLayoutPanel initialized?

Answer 1

So when is scrollbar for the
FlowLayoutPanel initialized?

This might sound like a smartalec answer: “When the control is drawn or placed on the form” which is the reason when you adjust the size of the form they are in sync.( they are being drawn again )

The solution is to manually add the scrollbars yourself.