flutter Material风格-弹出框、面板

1.SimpleDialog

简单对话框 

class _MyHomePageState extends State<MyHomePage> {
  dialog() {
    showDialog(context: context,
      builder: (BuildContext context){
      return SimpleDialog(
        title: Text("data"),
      );
      }
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: RaisedButton(
          child: Text("btn"),
          color: Colors.amberAccent,
          textColor: Colors.grey,
          onPressed: dialog,
        ),
      ),
    );
  }
}

 添加SimpleDialogOption

dialog() {
    showDialog(context: context,
      builder: (BuildContext context){
      return 
        SimpleDialog(
        title: Text("data"),
        children: <Widget>[
          SimpleDialogOption(
            child: Text("aa"),
            onPressed: (){
              print("aa");
            },
          ),
          SimpleDialogOption(
            child: Icon(Icons.pets),
            onPressed: (){
              print("pets");
            },
          ),
        ],
      );
      }
    );
  }

 

2.AlertDialog

报警对话框

Center(
              child: AlertDialog(
                title: Text("alert"),
                content: Text("How are you!!!"),
              ),
          )

内容可以使用任意控件

content: Icon(Icons.toys),

 添加按钮

AlertDialog(
                title: Text("alert"),
                content: Text("是否要删除数据?"),
                actions: [
                  FlatButton(child: Text("否")),
                  FlatButton(child: Text("是")),
                ],
                //高度
                elevation: 20 ,
              )

各种属性

AlertDialog(
                title: Text("alert"),
                content: Text("是否要删除数据?"),
                actions: [
                  FlatButton(child: Text("否")),
                  FlatButton(child: Text("是")),
                ],
                //高度
                elevation: 10 ,
                //背景色
                backgroundColor: Colors.white54,
                //形状
                shape: CircleBorder(),
              )

弹出

class _MyHomePageState extends State<MyHomePage> {
  alert() {
    showDialog(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Text("对话框"),
            content: Text("确定要删除数据吗?"),
            actions: <Widget>[
              FlatButton(
                child: Text("是的"),
                onPressed: () {
                  Navigator.pop(context);
                },
              ),
              FlatButton(
                child: Text("取消"),
                onPressed: () {
                  Navigator.pop(context);
                },
              ),
            ],
          );
        });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: RaisedButton(
          child: Text("按钮"),
          color: Colors.amberAccent,
          textColor: Colors.grey,
          onPressed: alert,
        ),
      ),
    );
  }
}

点击是或否触发事件

enum Action { OK, Cancel }

class _MyHomePageState extends State<MyHomePage> {
  String btn = "按钮";

  Future alert() async {
    final action = await showDialog(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Text("对话框"),
            content: Text("确定要删除数据吗?"),
            actions: <Widget>[
              FlatButton(
                child: Text("是的"),
                onPressed: () {
                  Navigator.pop(context,Action.OK);
                },
              ),
              FlatButton(
                child: Text("取消"),
                onPressed: () {
                  Navigator.pop(context,Action.Cancel);
                },
              ),
            ],
          );
        });
    switch (action) {
      case Action.OK:
        setState(() {
          //更新界面内容
          btn = "按钮OK";
        });
        break;
      case Action.Cancel:
        setState(() {
          btn = "按钮取消";
        });
        break;
      default:
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: RaisedButton(
          child: Text(btn),
          color: Colors.amberAccent,
          textColor: Colors.grey,
          onPressed: alert,
        ),
      ),
    );
  }
}

3.SnackBar

class app extends StatefulWidget {
  @override
  _appState createState() => _appState();
}

class _appState extends State<app> {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: RaisedButton(
        child: Text(""),
        color: Colors.lightBlue,
        onPressed: () {
          Scaffold.of(context).showSnackBar(SnackBar(
            content: Text("是否要退出"),
            action: SnackBarAction(
              label: "是",
              onPressed: (){
                Navigator.pop(context);
              },
            ),
          ));
        },
      ),
    );
  }
}

 //可以设置持续时间  duration: Duration(seconds: 5),

 注意Scaffold.of(context).showSnackBar() 上层  build(BuildContext context) 要在Scaffold(）之下 否则会报错：

Scaffold.of() called with a context that does not contain a Scaffold

4.BottomSheet

和snack不同，它会持久的显示底部的滑动窗口

Container(
          child: RaisedButton(
            child: Text("data"),
            onPressed: () {
              showModalBottomSheet(
                context: context,
                builder: (BuildContext context) {
                  return new Container(
                    height: 30.0,
                    child: Text("data"),
                  );
                },
              ).then((val) {});
            },
          ),
        )

5.ExpansionPanel 

收缩面板 

报错：RenderListBody must have unlimited space along its main axis.

主轴要有无线空间

class _MyHomePageState extends State<MyHomePage> {
  bool _isExpanded = false;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Container(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              ExpansionPanelList(
                //控制点击收缩
                expansionCallback: (int panelIndex, bool isExpanded){
                  setState(() {
                    _isExpanded = !isExpanded;
                  });
                },
                children: [
                  ExpansionPanel(
                      headerBuilder: (BuildContext context, bool isExpanded) {
                        return Container(
                          padding: EdgeInsets.all(16.0),
                          child: Text("aa"),
                        );
                      },
                      body: Container(
                        padding: EdgeInsets.all(16.0),
                         double.infinity,
                        child: Text("bbb"),
                      ),
                    //默认展开
                    isExpanded: _isExpanded,
                    canTapOnHeader: true
                  ),
                ],
              )
            ],
          ),
        ));
  }
}