我试图用当前的名称以相同的名称上传新的照片，然后开始提供错误并且还在模拟器中使用
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════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
The following assertion was thrown building:
'package:flutter/src/material/grid_tile.dart': Failed assertion: line 31 pos 17: 'child != null': is not true.
Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
https://github.com/flutter/flutter/issues/new?template=BUG.md
When the exception was thrown, this was the stack:
#2 new GridTile (package:flutter/src/material/grid_tile.dart:31:17)
#3 _SavedPageState.build.<anonymous closure> (package:hotel_hunter/Screens/savedPage.dart:46:18)
#4 SliverChildBuilderDelegate.build (package:flutter/src/widgets/sliver.dart:442:15)
#5 SliverMultiBoxAdaptorElement._build.<anonymous closure> (package:flutter/src/widgets/sliver.dart:1153:67)
#6 _HashMap.putIfAbsent (dart:collection-patch/collection_patch.dart:137:29)
...
════════════════════════════════════════════════════════════════════════════════════════════════════
════════ (2) Exception caught by widgets library ═══════════════════════════════════════════════════
'package:flutter/src/material/grid_tile.dart': Failed assertion: line 31 pos 17: 'child != null': is not true.
════════════════════════════════════════════════════════════════════════════════════════════════════
════════ (3) Exception caught by widgets library ═══════════════════════════════════════════════════
'package:flutter/src/material/grid_tile.dart': Failed assertion: line 31 pos 17: 'child != null': is not true.
════════════════════════════════════════════════════════════════════════════════════════════════════
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