flutter _overlay!=null

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Package:flutter/src/widgets/overlay.dart': Failed assertion: line 133 pos 12: '_overlay != null':
Asked 4 years, 8 months ago
Modified 1 year, 4 months ago
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16


entry is a instance of OverlayEntry class

entry?.remove();
Error

Package:flutter/src/widgets/overlay.dart': Failed assertion: line 133 pos 12: '_overlay != null':
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asked Jul 20, 2018 at 13:42
Ravindra Bhanderi's user avatar
Ravindra Bhanderi
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4 Answers
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12


If there is no OverlayEntry inserted to the Overlay and you try to call the remove method, you will get that error: Failed assertion: '_overlay != null'. So before removing the entry, add a condition to judge whether it is legal or not. It's more like a hack code, you can add a variable like isEntryNotNull for convenience and understandable as well. And when you insert a new OverlayEntry into Overlay, reassign it to the entry variable, then the condition will work fine.

if (entry != null) {
    
    
  entry.remove();
  entry = null;
}
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edited Mar 9, 2020 at 15:34
xiawi's user avatar
xiawi
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answered Mar 9, 2020 at 8:59
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While this code may answer the question, adding comments to explain how it works increase the long-term value of the answer. – 
xiawi
 Mar 9, 2020 at 9:22
Well, if there is no OverlayEntry inserted to the Overlay and you try to call the remove method, you will get that error: Failed assertion: '_overlay != null'. So before removing the entry, add a condition to judge whether it is legal or not. It's more like a hack code, you can add a variable like isEntryNotNull for convinience and understandable as well. And when you insert a new OverlayEntry into Overlay, reassign it to the entry variable, then the condition will work fine. – 
halface_sun
 Mar 9, 2020 at 10:10
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12


Resolved

After lots of research a try I found below a simple solution.

entry?.remove();
entry = null;
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edited Mar 13, 2020 at 5:49
answered Mar 11, 2020 at 5:10
Ravindra Bhanderi's user avatar
Ravindra Bhanderi
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6


try this, it is working for me

 if (overlayEntry != null && overlayEntry.mounted) {
    
    
  overlayEntry?.remove();
  overlayEntry = null;
}
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answered Nov 22, 2021 at 10:47
saigopi.me's user avatar
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2


You can check if the overlay is mounted like this

  if (floatingDropdown?.mounted ?? false) {
    
    
    floatingDropdown?.remove();
  }
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