问题
I have created a webapp that is exhibiting different behavior between an installed PWA and in normal mobile safari on iOS after an orientation change. When I flip my iPhone or iPad from portrait to landscape and back to portrait again, sometimes the portrait orientation will be zoomed in (and sometimes not). This only occurs in the installed progressive web app (PWA) and not when viewed in the normal mobile safari. Additionally, this behavior occurs only for an iOS PWA (both iPhone and iPad) and not for an Android PWA.
Do you have any ideas as to why this is occurring and/or possible remedies? I have already tried disabling zoom on orientation change, reordering my css for the different orientations, setting the focus to a large constant div prior to and after orientation change, and increasing default font/input sizes.
来源：https://stackoverflow.com/questions/50977145/unintended-zoom-on-orientation-change-in-pwa-but-not-mobile-safari-ios