This short video demonstrates how anchors can be used to build a flexible interface. The small white arrows show the anchors settings. This layout will properly scale to any screen size. Recommended video tutorial:
The anchors feature is simple to use and is very effective with implementing flexible layouts. By default the views position is relative to the top left corner. There is nothing special about this corner and there is no real reason for all views to be position based on the distance from this...
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The edit fields need to have left right anchors set.
For the button, I normally set the size and then use
btn.horizontalcenter = 50%x