How to call a method from navbar in Flutter - flutter

Question

I am trying to call a method from navbar, when I call the object the image has been selected not appears in the screen.
My goal is to do this, when I Click in Gallery and select new image, show this like in Screen 2.
The code for this interactions,
File imageFile;
_openGallery(BuildContext context) async{
var picture = await ImagePicker.pickImage(source:ImageSource.gallery);
this.setState((){
imageFile = picture;
});
Navigator.of(context).pop();
}
_openCamera(BuildContext context) async{
var picture = await ImagePicker.pickImage(source:ImageSource.camera);
this.setState((){
imageFile = picture;
});
Navigator.of(context).pop();
}
And the build widget
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
_decideImageView(),
RaisedButton(onPressed: (){
_showChoiceDialog(context);
},child: Text('Select Image'),),
_decideButton(context)
],
),
),
),
bottomNavigationBar: BottomNavigationBar(
type:BottomNavigationBarType.fixed,
onTap: (int index) {
if (index==0)
_openGallery(context);
if (index == 1)
_openCamera(context);
},
items: [
BottomNavigationBarItem(
icon: Icon(Icons.photo_library),
title: Text('Home')
),
BottomNavigationBarItem(
icon: Icon(Icons.camera_alt),
title: Text('Camera')
),
],
),
);
}
The function to decide if you will see a text asking for select a image or return the image on the screen is this one below, the method is called _decideImageView.
Widget _decideImageView(){
if(imageFile == null){
return Text('Kein Bild ausgewählt',
style: TextStyle(
color:Colors.black,
fontFamily: 'Lato',
fontSize: 25,
letterSpacing: 1.0
), );
}
else{
return Image.file(imageFile,width:400,height:400);
}
}

Answer 1

Try to remove this: Navigator.of(context).pop();
on the two ways to pick the picture, that's work for me, but you need to know that's not the best way to create an image picker.