uni-app引用F2包，pixelRatio指定分辨率时，报错window对象undefined

The issue which is not created via https://antv-issue-helper.surge.sh will be closed immediately.

---

注意：不是用 https://antv-issue-helper.surge.sh 创建的 issue 会被立即关闭。

The report mentions uni-app, the F2 package, pixelRatio, and a window object error, but provides no reproduction steps, files, tests, or entry point. Start by reproducing the error in a uni-app integration and identify where pixelRatio handling accesses window. Done means the error is reproduced, its scope is understood, and the relevant behavior is corrected with a regression check.

Written by the indexing model from the issue text.