How to style AlertDialog Actions in Flutter

问题:

I use this method to show a AlertDialog:

_onSubmit(message) {
    if (message.isNotEmpty) {
      showDialog(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Center(child: Text('Alert')),
            content: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children : <Widget>[
                Expanded(
                  child: Text(
                    message,
                    textAlign: TextAlign.center,
                    style: TextStyle(
                      color: Colors.red,

                    ),
                  ),
                )
              ],
            ),
            actions: <Widget>[
              FlatButton(
                  child: Text('Cancel'),
                  onPressed: () {
                    Navigator.of(context).pop();
                  }),
              FlatButton(
                  child: Text('Ok'),
                  onPressed: () {
                    _inputTextController.clear();
                    Navigator.of(context).pop();
                  })
            ],
          );
        },
      );
    }
  }

Everything is working but the buttons are aligned in right as shown on picture below:

I want to style some how the buttons, for example one on start other on end. I searched in docs but only found how to make them "Stacked full-width buttons". Any ideas how to style the buttons?

回答1:

Customize widget

Edit the the widget itself: Under the AlertDialog there is a ButtonBar widget where you can use alignment: MainAxisAlignment.spaceBetween to align the buttons correctly. See this answer for an example of a custom AlertDialog widget.

Own button row

You could also remove the buttons under actions and add an own custom Row with RaisedButtons in it, somehow like this:

Row (
    mainAxisAlignment: MainAxisAlignment.spaceBetween,
    children: <Widget>[
        RaisedButton(), // button 1
        RaisedButton(), // button 2
    ]
)

In your case you could add a Column around the Row in content and in there add your existing Row and the modified one you created from the above example.

回答2:

Don't add button in actions of AlertDialog. As you can see.

_onSubmit(message) {
    if (message.isNotEmpty) {
      showDialog(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Center(child: Text('Alert')),
            content: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children : <Widget>[
                Expanded(
                  child: Text(
                    message,
                    textAlign: TextAlign.center,
                    style: TextStyle(
                      color: Colors.red,

                    ),
                  ),
                ),

         FlatButton(
                  child: Text('Cancel'),
                  onPressed: () {
                    Navigator.of(context).pop();
                  }),
              FlatButton(
                  child: Text('Ok'),
                  onPressed: () {
                    _inputTextController.clear();
                    Navigator.of(context).pop();
                  })
              ],
            ),
          );
        },
      );
    }
  }

回答3:

Move buttons to content is a good solution.

showDialog(
              context: context,
              barrierDismissible: false,
              builder: (BuildContext context) {
                return AlertDialog(
                  title: Center(child: Text('Alert')),
                  content: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      Container(
                        child: Text(
                          "message",
                          textAlign: TextAlign.center,
                          style: TextStyle(
                            color: Colors.red,
                          ),
                        ),
                      ),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: <Widget>[
                          FlatButton(
                              child: Text('Yes'),
                              onPressed: () {
                                Navigator.of(context).pop();
                              }),
                          FlatButton(
                              child: Text('No'),
                              onPressed: () {
                                Navigator.of(context).pop();
                              })
                        ])
                    ],
                  ),
                );
              });

回答4:

Or you can use RFlutter Alert library for that. It is easily customizable and easy-to-use. Its default style includes rounded corners and you can add buttons as much as you want.

Alert Style:

var alertStyle = AlertStyle(
    animationType: AnimationType.fromTop,
    isCloseButton: false,
    isOverlayTapDismiss: false,
    descStyle: TextStyle(fontWeight: FontWeight.bold),
    animationDuration: Duration(milliseconds: 400),
    alertBorder: RoundedRectangleBorder(
    borderRadius: BorderRadius.circular(0.0),
    side: BorderSide(
        color: Colors.grey,
    ),
    ),
    titleStyle: TextStyle(
    color: Colors.red,
    ),
);

And assing your AlertStyle object to Alert's style field.

Alert(
    context: context,
    style: alertStyle,
    type: AlertType.info,
    title: "RFLUTTER ALERT",
    desc: "Flutter is more awesome with RFlutter Alert.",
    buttons: [
    DialogButton(
        child: Text(
        "COOL",
        style: TextStyle(color: Colors.white, fontSize: 20),
        ),
        onPressed: () => Navigator.pop(context),
        color: Color.fromRGBO(0, 179, 134, 1.0),
        radius: BorderRadius.circular(0.0),
    ),
    ],
).show();

*I'm one of developer of RFlutter Alert.