Flutter 在Flatter Web中上载多个文件(图像)
我希望用户在一个上载文件元素中上载(到本地内存)多个文件。我用的是颤振网。下面是我当前的代码。有什么想法吗Flutter 在Flatter Web中上载多个文件(图像),flutter,web,dart,Flutter,Web,Dart,我希望用户在一个上载文件元素中上载(到本地内存)多个文件。我用的是颤振网。下面是我当前的代码。有什么想法吗 import 'package:flutter/material.dart'; import 'dart:html' as html; import 'dart:typed_data'; import 'package:phototags/pages/tags_page.dart'; class HomePage extends StatefulWidget { HomePage(
import 'package:flutter/material.dart';
import 'dart:html' as html;
import 'dart:typed_data';
import 'package:phototags/pages/tags_page.dart';
class HomePage extends StatefulWidget {
HomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
// Code idea from: https://github.com/rjcalifornia/web_upload/blob/master/lib/widgets/web_upload.dart
List<Uint8List> _selectedFilesBytes;
GlobalKey<FormState> _formKey = new GlobalKey<FormState>();
List<Widget> children = [];
void startWebFilePicker() async {
html.InputElement uploadInput = html.FileUploadInputElement();
uploadInput.multiple = true;
uploadInput.draggable = true;
uploadInput.click();
uploadInput.onChange.listen((e) {
final files = uploadInput.files;
// _selectedFilesBytes = [];
for (var i = 0; i < files.length; i++) {
final file = files[i];
final reader = new html.FileReader();
reader.onLoadEnd.listen((event) {
_selectedFilesBytes.add(reader.result);
});
reader.onError.listen((event) {
print('there was an error');
});
reader.readAsArrayBuffer(file);
}
setState(() {
for (var imageBytes in _selectedFilesBytes) {
children.add(Image.memory(imageBytes));
}
});
});
}
导入“包装:颤振/材料.省道”;
将“dart:html”导入为html;
导入“dart:键入的_数据”;
导入“package:phototags/pages/tags_page.dart”;
类主页扩展了StatefulWidget{
主页({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_HomePageState createState()=>\u HomePageState();
}
类_HomePageState扩展状态{
//代码来自:https://github.com/rjcalifornia/web_upload/blob/master/lib/widgets/web_upload.dart
列出所选文件字节;
GlobalKey _formKey=新的GlobalKey();
列出子项=[];
void startWebFilePicker()异步{
html.InputElement uploadInput=html.FileUploadInputElement();
uploadInput.multiple=true;
uploadInput.draggable=true;
上传输入。单击();
uploadInput.onChange.listen((e){
最终文件=uploadInput.files;
//_selectedFilesBytes=[];
对于(var i=0;i
当前代码未显示任何错误,但似乎未将任何内容加载到“\u selectedFilesBytes”变量中。图像的位图似乎存储在临时输入所拥有的内存中,当应用程序进入构建时,该内存会被刷新。我已尝试使用
Image.memory(Uint8List.fromList(reader.result));
直接在for()循环中,将children变量转换为widget级别。这就解决了。这可能有解决方案: