问微件不在android中显示，但在ios中显示

EN

  Widget build(BuildContext context) {
    return Container(
        decoration: const BoxDecoration(
          image: const DecorationImage(
            fit: BoxFit.fill,
            image: const AssetImage("assets/images/background.png"),
          ),
        ),
        child: SafeArea(
          child: Column(
            children: <Widget>[
              Padding(
                padding: const EdgeInsets.all(100.0),
                child: SizedBox(
                  child: Image.asset("assets/images/logo.png"),
                  height: 120,
                ),
              ),
              Expanded(
                child: Align(
                  alignment: Alignment.bottomRight,
                  child: Padding(
                    padding: const EdgeInsets.fromLTRB(0,0,0,200.0),
                    child: LumiaFab(),
                  ),
                ),
              ),
              Column(
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.fromLTRB(0, 0, 0, 80),
                    child: FlatButton(
                      padding: EdgeInsets.fromLTRB(100,10, 100, 10),
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.all(
                          Radius.circular(10),
                        ),
                      ),
                      color: Colors.white,
                      child: Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: Text(
                          "Login or Sign Up",
                          style: TextStyle(
                            color: Color(0xFF009245),
                            fontSize: 14.0,
                          ),
                        ),
                      ),
                      onPressed: () {},
                    ),
                  ),
                ],
              )
            ],
          ),
        ));