AlertDialog class

A material design alert dialog.

An alert dialog informs the user about situations that require acknowledgement. An alert dialog has an optional title and an optional list of actions. The title is displayed above the content and the actions are displayed below the content.

If the content is too large to fit on the screen vertically, the dialog will display the title and the actions and let the content overflow, which is rarely desired. Consider using a scrolling widget for content, such as SingleChildScrollView, to avoid overflow. (However, be aware that since AlertDialog tries to size itself using the intrinsic dimensions of its children, widgets such as ListView, GridView, and CustomScrollView, which use lazy viewports, will not work. If this is a problem, consider using Dialog directly.)

For dialogs that offer the user a choice between several options, consider using a SimpleDialog.

Typically passed as the child widget to showDialog, which displays the dialog.

This snippet shows a method in a State which, when called, displays a dialog box and returns a Future that completes when the dialog is dismissed.
Future<void> _neverSatisfied() async {
  return showDialog<void>(
    context: context,
    barrierDismissible: false, // user must tap button!
    builder: (BuildContext context) {
      return AlertDialog(
        title: Text('Rewind and remember'),
        content: SingleChildScrollView(
          child: ListBody(
            children: <Widget>[
              Text('You will never be satisfied.'),
              Text('You\’re like me. I’m never satisfied.'),
        actions: <Widget>[
            child: Text('Regret'),
            onPressed: () {

See also:



AlertDialog({Key key, Widget title, EdgeInsetsGeometry titlePadding, TextStyle titleTextStyle, Widget content, EdgeInsetsGeometry contentPadding: const EdgeInsets.fromLTRB(24.0, 20.0, 24.0, 24.0), TextStyle contentTextStyle, List<Widget> actions, Color backgroundColor, double elevation, String semanticLabel, ShapeBorder shape})
Creates an alert dialog. [...]


actions List<Widget>
The (optional) set of actions that are displayed at the bottom of the dialog. [...]
backgroundColor Color
The background color of the surface of this Dialog. [...]
content Widget
The (optional) content of the dialog is displayed in the center of the dialog in a lighter font. [...]
contentPadding EdgeInsetsGeometry
Padding around the content. [...]
contentTextStyle TextStyle
Style for the text in the content of this AlertDialog. [...]
elevation double
The z-coordinate of this Dialog. [...]
semanticLabel String
The semantic label of the dialog used by accessibility frameworks to announce screen transitions when the dialog is opened and closed. [...]
shape ShapeBorder
The shape of this dialog's border. [...]
title Widget
The (optional) title of the dialog is displayed in a large font at the top of the dialog. [...]
titlePadding EdgeInsetsGeometry
Padding around the title. [...]
titleTextStyle TextStyle
Style for the text in the title of this AlertDialog. [...]
hashCode int
The hash code for this object. [...]
read-only, inherited
key Key
Controls how one widget replaces another widget in the tree.
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


build(BuildContext context) Widget
Describes the part of the user interface represented by this widget. [...]
createElement() StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
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.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toDiagnosticsNode({String name, DiagnosticsTreeStyle style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug}) String
Returns a string representation of this object.
toStringDeep({String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner: ', ', DiagnosticLevel minLevel: DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.


operator ==(dynamic other) bool
The equality operator. [...]