Problem pageview reload first page after setState ( Flutter ) - flutter

Question

I have a code, this code create a pageview about some user, data is get from firebase
return new Scaffold(
appBar: new AppBar(
title: new Text("Carousel"),
),
body: StreamBuilder<QuerySnapshot>(
stream: Firestore.instance.collection('users').snapshots(),
builder:
(BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) return new Text('Error: ${snapshot.error}');
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return new CircularProgressIndicator();
default:
return new PageView(
onPageChanged: _onPageViewChange,
controller: _controller,
scrollDirection: Axis.horizontal,
children:
snapshot.data.documents.map((DocumentSnapshot document) {
return new Column(
children: <Widget>[
new Container(
child: new ClipOval(
child: new CachedNetworkImage(
width: 150.0,
height: 150.0,
imageUrl: document['img'],
fit: BoxFit.fill,
placeholder: (context, url) =>
CircularProgressIndicator(),
errorWidget: (context, url, error) =>
Icon(Icons.error),
)),
),
new ListTile(
title: new Text(
isPerson
? 'My name is'
: (isPlace
? 'My favourite is'
: (isNote
? 'I am from'
: (isPhone
? 'My phone is'
: (isLock ? '' : '')))),
textAlign: TextAlign.center),
subtitle: new Text(
isPerson
? document['name']
: (isPlace
? document['place']
: (isNote
? document['note']
: (isPhone
? document['phone']
: (isLock
? document['lock'].toString()
: "")))),
textAlign: TextAlign.center,
),
),
buildButton1(Icons.person)
],
);
}).toList(),
);
}
},
));
}
this is fuction buildButton1()
Widget buildButton1(IconData icon) {
return new Column(
children: <Widget>[
new Container(
padding: EdgeInsets.only(left: 10.0, right: 10.0, top: 20.0),
child: new IconButton(
icon: Icon(icon),
onPressed: () {
setState(() {
//isChecked ? true : false;
isPerson = true;
isNote = false;
isPlace = false;
isPhone = false;
isLock = false;
});
},
iconSize: 32.0,
color: isPerson ? Colors.green : Colors.grey,
),
)
],
);
}
When I press a button to set variable then Pageview reload and show firstpage. How can I solved this problem. This is example picture https://imgur.com/nKC358E
................................................................................................

Answer 1

The issue comes from the _onPageViewChange function.
The last page doesn't return an integer value. If you have 3 pages, than the last returned index will be 1.99999999999... and not 2.
I solved the problem like this
onPageChanged: (index){
setState(() {
if (index > 1.99){
lastPage=true;
}else{
lastPage=false;
}
});
}