ErrorWidget class Null safety

A widget that renders an exception's message.

This widget is used when a build method fails, to help with determining where the problem lies. Exceptions are also logged to the console, which you can read using flutter logs. The console will also include additional information such as the stack trace for the exception.

It is possible to override this widget.

import 'package:flutter/material.dart';

void main() {
  ErrorWidget.builder = (FlutterErrorDetails details) {
    bool inDebug = false;
    assert(() { inDebug = true; return true; }());
    // In debug mode, use the normal error widget which shows
    // the error message:
    if (inDebug) {
      return ErrorWidget(details.exception);
    }
    // In release builds, show a yellow-on-blue message instead:
    return Container(
      alignment: Alignment.center,
      child: const Text(
        'Error!',
        style: const TextStyle(color: Colors.yellow),
        textDirection: TextDirection.ltr,
      ),
    );
  };
  // Here we would normally runApp() the root widget, but to demonstrate
  // the error handling we artificially fail:
  return runApp(Builder(
    builder: (BuildContext context) {
      throw 'oh no, an error';
    },
  ));
}

See also:

Inheritance

Constructors

ErrorWidget(Object exception)
Creates a widget that displays the given exception. [...]
ErrorWidget.withDetails({String message, FlutterError? error})
Creates a widget that displays the given error message. [...]

Properties

hashCode int
The hash code for this object. [...]
@nonVirtual, read-only, inherited
key Key?
Controls how one widget replaces another widget in the tree. [...]
final, inherited
message String
The message to display.
final
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

createElement() LeafRenderObjectElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
createRenderObject(BuildContext context) RenderBox
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget. [...]
override
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
override
didUnmountRenderObject(covariant RenderObject renderObject) → void
A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
A string representation of this object. [...]
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants. [...]
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object. [...]
inherited
toStringShort() String
A short, textual description of this widget.
inherited
updateRenderObject(BuildContext context, covariant RenderObject renderObject) → void
Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject. [...]
@protected, inherited

Operators

operator ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited

Static Properties

builder ErrorWidgetBuilder
The configurable factory for ErrorWidget. [...]
read / write