Overflow Error in Flutter when keyboard open

问题

I am designing a login page it overflowed when I click on any text form field it open keyboard and through overflow warning like this see attached image. I also want a Raised button icon should be on the right side of the button.

Widget build(BuildContext context) {
    return Container(
      child: Scaffold(
        body: Stack(
          fit: StackFit.expand,
          children: <Widget>[
            Container(
              decoration: BoxDecoration(
                  image: new DecorationImage(
                      image: new AssetImage('assets/login_page_bg_1.jpg'),
                      fit: BoxFit.cover,
                      colorFilter: new ColorFilter.mode(
                          Colors.black.withOpacity(0.55), BlendMode.dstATop))),
            ),
            Column(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Expanded(
                  flex: 1,
                  child: Container(
                    margin: new EdgeInsets.only(top: 42.0),
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        Image.asset('assets/logo.png',
                            width: 250.0, height: 200.21),
                      ],
                    ),
                  ),
                ),
                Expanded(
                  flex: 2,
                  child: Container(
                    margin: new EdgeInsets.only(bottom: 40.0),
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        //form filed goes here
                        Text('Login As User',
                            textAlign: TextAlign.center,
                            style: TextStyle(
                                fontWeight: FontWeight.bold, fontSize: 35.0)),
                        TextFormField(
                            keyboardType: TextInputType.emailAddress,
                            decoration: InputDecoration(
                              hintText: 'you@example.com',
                              labelText: 'Email Address',
                            ),
                        new Container(
                          // width: MediaQuery.of(context).size.width,
                          child: RaisedButton.icon(
                            color: Color.fromARGB(251, 188, 74, 1),
                            label: Text('LOGIN'),
                            icon: Icon(Icons.send,
                                size: 10.0, color: Colors.black),
                            onPressed: () {
                              this.submit();
                            }, ),)],),),)],)],),),);

Intital state

Error/overflowed State

回答1:

This is happening because when the keyboard comes on screen, the height of the canvas to draw decreases. One solution is to wrap your root container inside SingleChildScrollView like this :

Widget build(BuildContext context) {
return Scaffold(
      body: Stack(
        fit: StackFit.loose,
        children: <Widget>[
          Container(
            decoration: BoxDecoration(
                image: new DecorationImage(
                    image: new AssetImage('assets/login_page_bg_1.jpg'),
                    fit: BoxFit.cover,
                    colorFilter: new ColorFilter.mode(
                        Colors.black.withOpacity(0.55), BlendMode.dstATop)
                        )
            ),
          ),
          Column(
            mainAxisAlignment: MainAxisAlignment.start,
            children: <Widget>[
              SizedBox(height: 42,),
              Expanded(
                flex: 1,
                child: Center(
                  child:
                    Image.asset('assets/logo.png',
                        width: 250.0, height: 200.21),
                ),
              ),
              Expanded(
                flex: 2,
                child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                    //form filed goes here
                    Text('Login As User',
                    textAlign: TextAlign.center,
                    style: TextStyle(
                        fontWeight: FontWeight.bold, fontSize: 35.0)),
                TextFormField(
                  keyboardType: TextInputType.emailAddress,
                  decoration: InputDecoration(
                    hintText: 'you@example.com',
                    labelText: 'Email Address',
                  )
                ),
                  new Container(
                    // width: MediaQuery.of(context).size.width,
                    child: RaisedButton.icon(
                      color: Color.fromARGB(251, 188, 74, 1),
                      label: Text('LOGIN'),
                      icon: Icon(Icons.send,
                          size: 10.0, color: Colors.black),
                      onPressed: () {
                        //this.submit();
                      }, ),)],)),
              SizedBox(height: 40,)

            ],)],),);

It will make your screen scrollable when the height of the content gets more than the available height of the viewport.

回答2:

Set following property to false

Scaffold(
  resizeToAvoidBottomInset: false, 
  ... 
)

---

If you're having issues with overflow error, use SingleChildScrollView with it.

Scaffold(
  resizeToAvoidBottomInset: false, // set it to false
  body: SingleChildScrollView(child: YourBody()),
)

回答3:

A much simpler solution (source) seems to be just setting the Scaffold property resizeToAvoidBottomPadding to false. This works great with me:

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        resizeToAvoidBottomPadding: false,
        appBar: AppBar(...),
        body: ...

来源：https://stackoverflow.com/questions/55312583/overflow-error-in-flutter-when-keyboard-open