I need to load list cities dynamically from rest webservice and let user choose a city from alert dialog. My code:
createDialog() {
fetchCities().then((response) {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Wybierz miasto'),
content: Container(
height: 200.0,
width: 400.0,
child: ListView.builder(
shrinkWrap: true,
itemCount: response.length,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text(response[index].name),
onTap: () => citySelected(response[index].id),
);
},
),
),
);
}
);
});
}
Result - dialog is always 200x400, even if only 2 cities are available, there is an unnecessary room left at the bottom:
How to make dialog width/height to fit actual items size? If I ommit height and width parameters, I'm getting exception and no dialog shown. In native Android Java I never need to specify any dimensions, because dialog sizes itself automatically to fit.
How to fix my code to get dialog sized correctly? Note: that I don't know item count, it's dynamic.
[edit]
As suggested, I wrapped content with column:
createDialog() {
fetchCities().then((response) {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Wybierz miasto'),
content: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Container(
child: ListView.builder(
shrinkWrap: true,
itemCount: response.length,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text(response[index].name),
onTap: () => citySelected(response[index].id),
);
},
),
)
]
),
);
}
);
});
}
Result - exception:
I/flutter ( 5917): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════ I/flutter ( 5917): The following assertion was thrown during performLayout(): I/flutter ( 5917): RenderViewport does not support returning intrinsic dimensions. I/flutter ( 5917): Calculating the intrinsic dimensions would require instantiating every child of the viewport, which I/flutter ( 5917): defeats the point of viewports being lazy.
More generic code to test:
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Select city'),
content: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Container(
child: ListView.builder(
shrinkWrap: true,
itemCount: 2,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text("City"),
onTap: () => {},
);
},
),
)
]
),
);
}
);
