【发布时间】：2020-09-18 11:25:35
【问题描述】：
我正在使用文件选择器插件来选择图像我想在下面的屏幕上显示选择的图像是我的代码我能够选择图像名称和路径并将它们显示为我的应用程序中的文本但无法将它们显示为图像，显示这些图像后，我想将图像上传到 Firebase 存储。
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:file_picker/file_picker.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => new _MyAppState();
}
class _MyAppState extends State<MyApp> {
final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
String _fileName;
String _path;
Map<String, String> _paths;
String _extension;
bool _loadingPath = false;
bool _multiPick = false;
FileType _pickingType = FileType.any;
TextEditingController _controller = new TextEditingController();
@override
void initState() {
super.initState();
_controller.addListener(() => _extension = _controller.text);
}
void _openFileExplorer() async {
setState(() => _loadingPath = true);
try {
if (_multiPick) {
_path = null;
_paths = await FilePicker.getMultiFilePath(
type: _pickingType,
allowedExtensions: (_extension?.isNotEmpty ?? false)
? _extension?.replaceAll(' ', '')?.split(',')
: null);
} else {
_paths = null;
_path = await FilePicker.getFilePath(
type: _pickingType,
allowedExtensions: (_extension?.isNotEmpty ?? false)
? _extension?.replaceAll(' ', '')?.split(',')
: null);
}
} on PlatformException catch (e) {
print("Unsupported operation" + e.toString());
}
if (!mounted) return;
setState(() {
_loadingPath = false;
_fileName = _path != null
? _path.split('/').last
: _paths != null ? _paths.keys.toString() : '...';
});
}
void _clearCachedFiles() {
FilePicker.clearTemporaryFiles().then((result) {
_scaffoldKey.currentState.showSnackBar(
SnackBar(
backgroundColor: result ? Colors.green : Colors.red,
content: Text((result
? 'Temporary files removed with success.'
: 'Failed to clean temporary files')),
),
);
});
}
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
key: _scaffoldKey,
appBar: new AppBar(
title: const Text('File Picker example app'),
),
body: new Center(
child: new Padding(
padding: const EdgeInsets.only(left: 10.0, right: 10.0),
child: new SingleChildScrollView(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Padding(
padding: const EdgeInsets.only(top: 20.0),
child: new DropdownButton(
hint: new Text('LOAD PATH FROM'),
value: _pickingType,
items: <DropdownMenuItem>[
new DropdownMenuItem(
child: new Text('FROM AUDIO'),
value: FileType.audio,
),
new DropdownMenuItem(
child: new Text('FROM IMAGE'),
value: FileType.image,
),
new DropdownMenuItem(
child: new Text('FROM VIDEO'),
value: FileType.video,
),
new DropdownMenuItem(
child: new Text('FROM MEDIA'),
value: FileType.media,
),
new DropdownMenuItem(
child: new Text('FROM ANY'),
value: FileType.any,
),
new DropdownMenuItem(
child: new Text('CUSTOM FORMAT'),
value: FileType.custom,
),
],
onChanged: (value) => setState(() {
_pickingType = value;
if (_pickingType != FileType.custom) {
_controller.text = _extension = '';
}
})),
),
new ConstrainedBox(
constraints: BoxConstraints.tightFor(width: 100.0),
child: _pickingType == FileType.custom
? new TextFormField(
maxLength: 15,
autovalidate: true,
controller: _controller,
decoration:
InputDecoration(labelText: 'File extension'),
keyboardType: TextInputType.text,
textCapitalization: TextCapitalization.none,
)
: new Container(),
),
new ConstrainedBox(
constraints: BoxConstraints.tightFor(width: 200.0),
child: new SwitchListTile.adaptive(
title: new Text('Pick multiple files',
textAlign: TextAlign.right),
onChanged: (bool value) =>
setState(() => _multiPick = value),
value: _multiPick,
),
),
new Padding(
padding: const EdgeInsets.only(top: 50.0, bottom: 20.0),
child: Column(
children: <Widget>[
new RaisedButton(
onPressed: () => _openFileExplorer(),
child: new Text("Open file picker"),
),
new RaisedButton(
onPressed: () => _clearCachedFiles(),
child: new Text("Clear temporary files"),
),
],
),
),
new Builder(
builder: (BuildContext context) => _loadingPath
? Padding(
padding: const EdgeInsets.only(bottom: 10.0),
child: const CircularProgressIndicator())
: _path != null || _paths != null
? new Container(
padding: const EdgeInsets.only(bottom: 30.0),
height: MediaQuery.of(context).size.height * 0.50,
child: new Scrollbar(
child: new ListView.separated(
itemCount: _paths != null && _paths.isNotEmpty
? _paths.length
: 1,
itemBuilder: (BuildContext context, int index) {
final bool isMultiPath =
_paths != null && _paths.isNotEmpty;
final String name = 'File $index: ' +
(isMultiPath
? _paths.keys.toList()[index]
: _fileName ?? '...');
final path = isMultiPath
? _paths.values.toList()[index].toString()
: _path;
return new ListTile(
title: new Text(
name,
),
subtitle: new Text(_path),
);
},
separatorBuilder:
(BuildContext context, int index) =>
new Divider(),
)),
)
: new Container(),
),
],
),
),
)),
),
);
}
}
【问题讨论】：
标签： flutter dart filepicker.io