WeChat Mini Programs Mobile phone Virtual Button and canvas layout problem

<canvas style="width:{{width}}; height: {{height}};" canvas-id="firstCanvas">
  <cover-view class="button_full" bindtap="saveIMG" style="position: fixed; height:50px; padding:0px; line-height:50px; text-align:center; bottom:0px; color:-sharpFFF;"></cover-view>
</canvas>

the page layout is as above, which is normal when the Android virtual button is displayed, but after putting it away, the layout of the Save Picture button has changed. what is the problem?

Css WeChat-Mini-Programs
Mar.18,2021

Previous: Will database transactional integrity be guaranteed when tomcat shuts down?

Next: Use python image to make random diagrams

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e44e19-44278.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e44e19-44278.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?