dart

问题 How can I convert a jpg image selected from photo gallery to png image in flutter? 回答1: Take a look at the image package. The following is a snippet available in the examples section, which converts JPEG to PNG : import 'dart:io'; import 'package:image/image.dart'; void main() { // Read a jpeg image from file. Image image = decodeImage(new File('test.jpg').readAsBytesSync()); // Resize the image to a 120x? thumbnail (maintaining the aspect ratio). Image thumbnail = copyResize(image, 120); //

问题 I'm building an app that shows an image taken from source.unsplash. My request url is: https://source.unsplash.com/random/`$widthx$height` Then the service redirects to some specific image url picked fitting my width and height. I can show the image with: Image.network(url above) , but I cannot access the new redirected url for some other parts of my code which is really necessary. Is there a way to get it? Thanks in advance Something I'm searching for is like Http.Response response = await

问题 I'm building an app that shows an image taken from source.unsplash. My request url is: https://source.unsplash.com/random/`$widthx$height` Then the service redirects to some specific image url picked fitting my width and height. I can show the image with: Image.network(url above) , but I cannot access the new redirected url for some other parts of my code which is really necessary. Is there a way to get it? Thanks in advance Something I'm searching for is like Http.Response response = await

问题 when i retrieve data from our website url, that return this output in one of rest api fields and i try to found if tracks is contained i get url from that which in this below tracks source is that i need to get String test = """ <div class=\"wp-playlist wp-audio-playlist wp-playlist-light\">\n <div class=\"wp-playlist-current-item\"></div>\n <p>\t\t<audio controls=\"controls\" preload=\"none\" width=\"\n\t\t\t\t1118\t\"\n\t\t> </audio></p>\n<div class=\"wp-playlist-next\"></div>\n<div class=\

问题 when i retrieve data from our website url, that return this output in one of rest api fields and i try to found if tracks is contained i get url from that which in this below tracks source is that i need to get String test = """ <div class=\"wp-playlist wp-audio-playlist wp-playlist-light\">\n <div class=\"wp-playlist-current-item\"></div>\n <p>\t\t<audio controls=\"controls\" preload=\"none\" width=\"\n\t\t\t\t1118\t\"\n\t\t> </audio></p>\n<div class=\"wp-playlist-next\"></div>\n<div class=\

问题 I have a main widget screen contain two main widgets a Header (marked with red) and a list (marked with purple) here is my code for that : class ScreenClient extends StatefulWidget { _ClientState createState() => _ClientState(); } class _ClientState extends State<ScreenClient> { @override Widget build(BuildContext context) { return Column( mainAxisAlignment: MainAxisAlignment.start, children: <Widget>[ ClientHeader(), // this is my header widget red Expanded( child: ClientList(), // this is

问题 Using the example in How to Create DropdownButton with a list of JSON Data and I want it to populate my DropDownButton in Flutter I have created the following working example: main.dart import 'package:flutter/material.dart'; import 'dart:convert'; void main() => runApp(MyApp()); class MyApp extends StatefulWidget { MyApp({Key key}) : super(key: key); @override _MyAppState createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { final String jsonData = '[{"id":"e20c","name":

问题 UPI not working in a flutter, I tried much time into my app with differents UPI app and different library from pub.dev upi_india (not working) upi_pay (not working) flutter_upi (not working) Errors : Too many attempts more than 10 time Risk threshold exceed Payment failure (code : U16) you've exceeded maximum transaction amount set by your bank GPay, BHIM, PhonePe, PayTm all transactions failed in this apps using with flutter 3rd party upi libraries Some of the libraries are discontinued from

问题 UPI not working in a flutter, I tried much time into my app with differents UPI app and different library from pub.dev upi_india (not working) upi_pay (not working) flutter_upi (not working) Errors : Too many attempts more than 10 time Risk threshold exceed Payment failure (code : U16) you've exceeded maximum transaction amount set by your bank GPay, BHIM, PhonePe, PayTm all transactions failed in this apps using with flutter 3rd party upi libraries Some of the libraries are discontinued from

问题 @override Widget build(BuildContext context) { super.build(context); SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values); return AnnotatedRegion<SystemUiOverlayStyle>( value: SystemUiOverlayStyle( statusBarColor: Colors.transparent, ), child: Scaffold( key: _scaffoldKeyProfilePage, body: DefaultTabController( length: 2, child:RefreshIndicator( onRefresh: _onRefresh, child: NestedScrollView( headerSliverBuilder: (context, _) { return [ SliverList( delegate: SliverChildListDelegate(