How to fix the size of the marquee

In the OrgChartStatic example, when you hold down the Ctrl key to scroll the wheel, the graphic on the chart will change size. The red box in the OverviewDiv in the upper left corner will change the size. How to achieve the selection does not change the size, but the diagram on the left changes. Size, how to set the width and height of the red marquee

Do you mean the pink box? That is meant to show what is currently in the viewport of the observed diagram, so it would be odd to change that. I’m not clear on what you’re trying to achieve.

I want to achieve the following effect, how can I do it?
thank

You won’t be able to use an overview for that. As I said, the overview will always show the whole observed diagram, with the box serving to represent the viewport.

You’ll need to create something custom. Maybe the Local View sample is something you can draw from. It seems like you just want a smaller diagram that has a smaller scale.

Thank you very much for your answer,How can I modify the border color, border width and background color of the pin box?

You can set the Overview.box. See how the default one is defined at https://gojs.net/latest/extensions/templates.js in the setupOverviewBox function.