Dart 如何将水平卡片转盘视图添加到颤振应用程序
您好,我正在使用Flatter制作instagram克隆,对于订阅源,我希望图像显示在水平卡片传送带视图中,以显示您关注的用户的帖子 以下是当前提要代码:Dart 如何将水平卡片转盘视图添加到颤振应用程序,dart,flutter,flutter-layout,Dart,Flutter,Flutter Layout,您好,我正在使用Flatter制作instagram克隆,对于订阅源,我希望图像显示在水平卡片传送带视图中,以显示您关注的用户的帖子 以下是当前提要代码: import 'package:flutter/material.dart'; import 'image_post.dart'; import 'dart:async'; import 'package:async/async.dart'; import 'main.dart'; import 'dart:io'; import 'dart
import 'package:flutter/material.dart';
import 'image_post.dart';
import 'dart:async';
import 'package:async/async.dart';
import 'main.dart';
import 'dart:io';
import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
class Feed extends StatefulWidget {
_Feed createState() => new _Feed();
}
class _Feed extends State<Feed> {
List<ImagePost> feedData;
@override
void initState() {
super.initState();
this._loadFeed();
}
buildFeed() {
if (feedData != null) {
return new ListView(
children: feedData,
);
} else {
return new Container(
alignment: FractionalOffset.center,
child: new CircularProgressIndicator());
}
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: const Text('InstaGroove',
style: const TextStyle(
fontFamily: "Billabong", color: Colors.black, fontSize: 35.0)),
centerTitle: true,
backgroundColor: Colors.white,
),
body: new RefreshIndicator(
onRefresh: _refresh,
child: buildFeed(),
),
);
}
Future<Null> _refresh() async {
await _getFeed();
setState(() {
});
return;
}
_loadFeed() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
String json = prefs.getString("feed");
if (json != null) {
List<Map<String, dynamic>> data =
jsonDecode(json).cast<Map<String, dynamic>>();
List<ImagePost> listOfPosts = _generateFeed(data);
setState(() {
feedData = listOfPosts;
});
} else {
_getFeed();
}
}
_getFeed() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
String userId = googleSignIn.currentUser.id.toString();
var url =
'https://us-central1-mp-rps.cloudfunctions.net/getFeed?uid=' + userId;
var httpClient = new HttpClient();
List<ImagePost> listOfPosts;
String result;
try {
var request = await httpClient.getUrl(Uri.parse(url));
var response = await request.close();
if (response.statusCode == HttpStatus.OK) {
String json = await response.transform(utf8.decoder).join();
prefs.setString("feed", json);
List<Map<String, dynamic>> data =
jsonDecode(json).cast<Map<String, dynamic>>();
listOfPosts = _generateFeed(data);
} else {
result =
'Error getting a feed:\nHttp status ${response.statusCode}';
}
} catch (exception) {
result =
'Failed invoking the getFeed function. Exception: $exception';
}
print(result);
setState(() {
feedData = listOfPosts;
});
}
List<ImagePost> _generateFeed(List<Map<String, dynamic>> feedData) {
List<ImagePost> listOfPosts = [];
for (var postData in feedData) {
listOfPosts.add(new ImagePost.fromJSON(postData));
}
return listOfPosts;
}
}
导入“包装:颤振/材料.省道”;
导入“image_post.dart”;
导入“dart:async”;
导入“包:async/async.dart”;
导入“main.dart”;
导入“dart:io”;
导入“dart:convert”;
导入“package:shared_preferences/shared_preferences.dart”;
类提要扩展了StatefulWidget{
_Feed createState()=>new_Feed();
}
类_提要扩展了状态{
列出数据;
@凌驾
void initState(){
super.initState();
这个;
}
buildFeed(){
如果(feedData!=null){
返回新的ListView(
儿童:feedData,
);
}否则{
退回新货柜(
对齐:分馏loffset.center,
子对象:新循环ProgressIndicator());
}
}
@凌驾
小部件构建(构建上下文){
归还新脚手架(
appBar:新的appBar(
标题:常量文本(“InstaGroove”,
样式:consttextstyle(
fontFamily:“Billabong”,颜色:Colors.black,fontSize:35.0),
标题:对,
背景颜色:Colors.white,
),
正文:新的刷新指示器(
onRefresh:\u refresh,
子级:buildFeed(),
),
);
}
Future\u refresh()异步{
等待_getFeed();
设置状态(){
});
返回;
}
_loadFeed()异步{
SharedReferences prefs=等待SharedReferences.getInstance();
String json=prefs.getString(“提要”);
if(json!=null){
列表数据=
jsonDecode(json.cast();
listOfPosts=\u generateFeed(数据);
设置状态(){
feedData=邮件列表;
});
}否则{
_getFeed();
}
}
_getFeed()异步{
SharedReferences prefs=等待SharedReferences.getInstance();
字符串userId=googleSignIn.currentUser.id.toString();
变量url=
'https://us-central1-mp-rps.cloudfunctions.net/getFeed?uid='+用户ID;
var httpClient=新的httpClient();
邮件列表;
字符串结果;
试一试{
var request=wait-httpClient.getUrl(Uri.parse(url));
var response=wait request.close();
if(response.statusCode==HttpStatus.OK){
String json=wait response.transform(utf8.decoder.join();
prefs.setString(“提要”,json);
列表数据=
jsonDecode(json.cast();
listOfPosts=\u generateFeed(数据);
}否则{
结果=
'获取提要时出错:\nHttp status${response.statusCode}';
}
}捕获(例外){
结果=
'调用getFeed函数失败。异常:$Exception';
}
打印(结果);
设置状态(){
feedData=邮件列表;
});
}
列表_generateFeed(列表feedData){
listOfPosts=[];
for(feedData中的var postData){
添加(新的ImagePost.fromJSON(postData));
}
返回邮件列表;
}
}
我在谷歌和youtube上做了一些研究,但我不知道如何将卡片转盘添加到我的应用程序的提要部分。我还是一个新手,所以任何帮助都是令人惊奇的!提前谢谢!!:) 试试这段代码。这是一个示例图像转盘屏幕。目前,使用的是硬编码图像列表,您可以根据api调用中的图像列表创建
image.network()
的动态列表
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
class TestImageCarousel extends StatefulWidget {
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return _TestImageCarousel();
}
}
class _TestImageCarousel extends State<TestImageCarousel> {
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return Material(
child: Stack(
children: <Widget>[
PageView(
onPageChanged: (id) {
//code to handle page change
},
scrollDirection: Axis.horizontal,
children: getImageList(),
),
],
));
}
}
/*
Get image list to populate in carousel
*/
getImageList() {
return <Widget>[
Padding(
padding: EdgeInsets.only(left: 1, right: 1),
child: Image.network("https://www.gstatic.com/webp/gallery/1.jpg",
fit: BoxFit.fill),
),
Padding(
padding: EdgeInsets.only(left: 1, right: 1),
child: Image.network("https://www.gstatic.com/webp/gallery/2.jpg",
fit: BoxFit.fill),
),
Padding(
padding: EdgeInsets.only(left: 1, right: 1),
child: Image.network("https://www.gstatic.com/webp/gallery/3.jpg",
fit: BoxFit.fill),
),
Padding(
padding: EdgeInsets.only(left: 1, right: 1),
child: Image.network("https://www.gstatic.com/webp/gallery/4.jpg",
fit: BoxFit.fill),
)
];
}
import'包装:flift/cupertino.dart';
进口“包装:颤振/材料.省道”;
类TestImageCarousel扩展StatefulWidget{
@凌驾
状态createState(){
//TODO:实现createState
返回_TestImageCarousel();
}
}
类_TestImageCarousel扩展状态{
@凌驾
void initState(){
super.initState();
}
@凌驾
小部件构建(构建上下文){
退货(
子:堆栈(
儿童:[
页面浏览(
onPageChanged:(id){
//处理页面更改的代码
},
滚动方向:轴水平,
子项:getImageList(),
),
],
));
}
}
/*
获取要在旋转木马中填充的图像列表
*/
getImageList(){
返回[
填充物(
填充:仅限边设置(左:1,右:1),
子项:Image.network(“https://www.gstatic.com/webp/gallery/1.jpg",
适合:BoxFit.填充),
),
填充物(
填充:仅限边设置(左:1,右:1),
子项:Image.network(“https://www.gstatic.com/webp/gallery/2.jpg",
适合:BoxFit.填充),
),
填充物(
填充:仅限边设置(左:1,右:1),
子项:Image.network(“https://www.gstatic.com/webp/gallery/3.jpg",
适合:BoxFit.填充),
),
填充物(
填充:仅限边设置(左:1,右:1),
子项:Image.network(“https://www.gstatic.com/webp/gallery/4.jpg",
适合:BoxFit.填充),
)
];
}
现在,您可以通过网络调用获取提要图像列表,并将列表绑定到image.network(“src”)
。您还可以添加页面控制器以获得自动旋转木马效果。在InkWell()
中添加此图像以获取onTap侦听器