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@figengungor
Last active October 12, 2018 11:08
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Image Cache Clear Issue
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:http/http.dart' as http;
import 'package:flutter/painting.dart' as painting;
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: PhotosPage(),
);
}
}
class PhotosPage extends StatefulWidget {
@override
_PhotosPageState createState() => _PhotosPageState();
}
class _PhotosPageState extends State<PhotosPage> {
Future<List<Photo>> _futurePhotos;
@override
void initState() {
super.initState();
_futurePhotos = JsonPlaceholderApi().getPhotos();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("Photos"),),
body: RefreshIndicator(
child: Center(
child: FutureBuilder<List<Photo>>(
future: _futurePhotos,
builder: (context, snapshot) {
if (snapshot.hasData) {
return _getGridView(snapshot.data);
} else if (snapshot.hasError) {
return getErrorMessage(snapshot.error, _onRetryPressed);
}
// By default, show a loading spinner
return CircularProgressIndicator();
},
),
), onRefresh: _handleRefresh,
),
);
}
_getGridView(List<Photo> data) {
if (data.isNotEmpty) {
return GridView.builder(
itemCount: data.length,
itemBuilder: (context, index) {
return _getGridItem(data[index]);
},
gridDelegate:
SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
);
} else {
return Center(child: Text('No data found.'));
}
}
_getGridItem(Photo photo) {
return GridTile(
child: Image.network(
photo.thumbnailUrl,
fit: BoxFit.cover,
),
footer: Container(
color: Color(0x60000000),
padding: EdgeInsets.all(8.0),
child: Text(
photo.title,
style: TextStyle(color: Colors.white),
)),
);
}
_onRetryPressed() {
setState(() {
_futurePhotos = JsonPlaceholderApi().getPhotos();
});
}
Future<Null> _handleRefresh() async {
setState(() {
_futurePhotos = JsonPlaceholderApi().getPhotos();
});
painting.imageCache.clear();
return null;
}
}
class JsonPlaceholderApi {
static const String baseUrl = 'jsonplaceholder.typicode.com';
static const String photosPath = 'photos';
Future<List<Photo>> getPhotos() async {
final uri = Uri.https(baseUrl, photosPath);
final jsonResponse = await _getJsonResponse(uri);
final photos = jsonResponse
.map<Photo>((dynamic item) => Photo.fromJson(item))
.toList();
return photos;
}
Future<List<dynamic>> _getJsonResponse(Uri uri) async {
var httpResponse = await http.get(uri);
if (httpResponse.statusCode == HttpStatus.OK) {
var jsonResponse = json.decode(httpResponse.body);
return jsonResponse;
} else {
throw Exception('\nStatus code:${httpResponse.statusCode}');
}
}
}
class Photo {
final int albumId;
final int id;
final String title;
final String url;
final String thumbnailUrl;
Photo.fromJson(Map<String, dynamic> jsonMap)
: this.albumId = jsonMap['albumId'],
this.id = jsonMap['id'],
this.title = jsonMap['title'],
this.url = jsonMap['url'],
this.thumbnailUrl = jsonMap['thumbnailUrl'];
}
getErrorMessage(Object error, VoidCallback onRetryPressed) {
var errorMessage;
if (error is TimeoutException) {
errorMessage = 'Time out';
} else if (error is IOException) {
errorMessage = 'No Internet Connection';
} else {
errorMessage = error.toString();
}
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
"$errorMessage",
textAlign: TextAlign.center,
),
SizedBox(
height: 16.0,
),
RaisedButton(
onPressed: onRetryPressed,
child: Text('Retry'),
),
],
);
}
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