# How do I get the proportion of the Vertical bar?

Hi there,
I have a new question, I would like to scroll my text in my ScrollBar. I managed to do that, but now I would like to be able to get the size of the Vertical bar back from the thing that goes down into my vertical bar. I did some research in the documentation and everything but the only size I can find is the total size of the vertical Bar. Do you have a way to find the proportion of the small scrolling bar in the vertical Bar, so that I can vary the scrolling speed.
Thank you in advance, Mathieu

pinging @JohnK who authored the control

Good question for which I do not have a good answer. The bars are based on the slider control and as far as I know the slider thumb is based on the overall size of the slider and so on the overall size of the scroll viewer and its contents.

I did not build in a method of changing the size of the slider thumb to control the speed. Sorry.

I donâ€™t want to change the size, I want to know the proportion between the vertical bar and the slider thumb so I can maybe do (size of the slider/ size of vertical bar) to control the speed. But It seems we canâ€™t do that for now ^^ Thank you

Hi there,
I might (I hope it is a may or only have ) have a solution. Despite we canâ€™t have the size of the sliders, we can have the number of lines in the TextBlock with the property â€śTextBlock.linesâ€ť, so If I have a speed for 14 lines of text for example, and I want the same speed for a text of 100 lines, Itâ€™s only a cross product I guess. I will try that way, I keep you in touch !

Hey,
So I have tried my way. It works , but itâ€™s not a cross product.
In my case, I have a text of 17 lines, with a speed of 0.005 ( I have chosen this speed). Now I have a text of 120 lines. I would like to know the speed of the slider. If we do( 0.005x120/17) (cross product) , we have a the speed to read the text with the same time between the begin of the text and the end and not the â€śsame proportion speedâ€ť. Itâ€™s not what I wanted. But if you do (0.005x17)/120, you have the same â€śproportionâ€ť speed. It is a kind of â€śspeed/lineâ€ť I was looking for.
I put that there if it can help someone.
Bye, Mathieu

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