你好，我想在屏幕上显示代码底部的填充部分，延迟10秒.我该怎么做

Question

我想在屏幕上显示代码底部的填充部分，延迟10秒。我该怎么做？

我的代码：

import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutter_clipboard_manager/flutter_clipboard_manager.dart';
import 'package:http/http.dart' as http;
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'URL Shortener',
theme: ThemeData(
primarySwatch: Colors.purple,
),
home: StartPage(),
);
}
}
class StartPage extends StatefulWidget {
@override
_StartPageState createState() => _StartPageState();
}
class _StartPageState extends State<StartPage> {
bool visibilityTag = false;
void _changed(bool visibility, String field) {
setState(() {
if (field == "tag") {
visibilityTag = visibility;
}
});
}
final GlobalKey<ScaffoldState> _globalKey = GlobalKey<ScaffoldState>();
String shortUrl = "";
String value = "";
String buttonText = "COPY!";
bool isChanged = true;
TextEditingController urlcontroller = TextEditingController();
getData() async {
var url = 'https://api.shrtco.de/v2/shorten?url=${urlcontroller.text}';
var response = await http.get(url);
var result = jsonDecode(response.body);
if (result['ok']) {
setState(() {
shortUrl = result['result']['short_link'];
});
} else {
print(response);
}
}
copy(String url) {
FlutterClipboardManager.copyToClipBoard(url).then((value) {});
}
buildRow(String data, bool original) {
return SingleChildScrollView(
child: original
? Container(
alignment: Alignment.center,
child: Text(
data,
))
: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Text(
data,
),
ElevatedButton(
child: Text(buttonText),
style: ElevatedButton.styleFrom(
primary: Colors.blue,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0)),
minimumSize: Size(300, 40),
),
onPressed: () {
copy(shortUrl);
setState(() {
if (isChanged == true) {
buttonText = "COPIED!";
}
});
},
),
],
),
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[300],
body: ListView(
children: [
SvgPicture.asset(
'assets/logo.svg',
),
SvgPicture.asset(
'assets/illustration.svg',
),
Center(
child: Text(
"Let's get started!",
style: TextStyle(
fontSize: 20,
color: Color.fromRGBO(53, 50, 62, 10),
fontWeight: FontWeight.bold),
),
),
Center(
child: SizedBox(
width: 200,
height: 60,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
"Paste your first link into the field to shorten it",
textAlign: TextAlign.center,
style: TextStyle(
fontSize: 15,
color: Color.fromRGBO(76, 74, 85, 10),
fontWeight: FontWeight.bold)),
),
),
),
SizedBox(
height: 130,
child: Stack(
alignment: Alignment.center,
children: [
Container(
alignment: Alignment.centerRight,
color: Color.fromRGBO(59, 48, 84, 1),
child: SvgPicture.asset(
'assets/shape.svg',
color: Color.fromRGBO(75, 63, 107, 1),
),
),
Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
SizedBox(
width: 300,
height: 40,
child: TextField(
onChanged: (text) {
value = "URL : " + text;
},
controller: urlcontroller,
textAlign: TextAlign.center,
decoration: InputDecoration(
contentPadding: EdgeInsets.all(10.0),
border: OutlineInputBorder(
borderRadius: const BorderRadius.all(
const Radius.circular(10.0),
),
borderSide: BorderSide(
width: 0,
style: BorderStyle.none,
),
),
fillColor: Colors.white,
filled: true,
hintText: 'Shorten a link here ...'),
),
),
SizedBox(
height: 10,
),
SizedBox(
width: 300,
child: ElevatedButton(
onPressed: getData,
style: ElevatedButton.styleFrom(
primary: Colors.blue,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0)),
minimumSize: Size(60, 40),
),
child: Text('SHORTEN IT!'),
),
),
],
),
],
),
),
Padding(
padding: const EdgeInsets.all(13.0),
child: Container(
color: Colors.white,
width: double.infinity,
child: Column(
children: [
SizedBox(
height: 10,
),
buildRow(value, true),
buildRow(shortUrl, false),
],
),
),
)
],
),
);
}
}

你好，我想在屏幕上显示代码底部的填充部分，延迟10秒。我该怎么做？你好，我想在屏幕上显示代码底部的填充部分，延迟10秒。我该怎么做？你好，我想在屏幕上显示代码底部的填充部分，延迟10秒。我该怎么做？你好，我想在屏幕上显示代码底部的填充部分，延迟10秒。我该怎么做？

Answer 1

On State创建类似于bool的

bool showCopyButton = false;

更改为true

SizedBox(
width: 300,
child: ElevatedButton(
onPressed: ()async {
print("Button Click");
await getData();
setState(() {
showCopyButton = true;
});
},
style: ElevatedButton.styleFrom(
primary: Colors.blue,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10.0)),
minimumSize: Size(60, 40),
),
child: Text('SHORTEN IT!'),
),
),

用类似Visibility的包裹

Visibility(
visible: showCopyButton,
child: Padding(
padding: const EdgeInsets.all(13.0),
child: Container(
color: Colors.white,
width: double.infinity,
child: Column(
children: [
SizedBox(
height: 10,
),
buildRow("Text ", true),
buildRow("asdad", false),
],
),
),
),
)

或者你可以像一样只使用if

if (showCopyButton)
Padding(
padding: const EdgeInsets.all(13.0),
child: Container(
color: Colors.white,
width: double.infinity,
child: Column(
children: [
SizedBox(
height: 10,
),
buildRow("Text ", true),
buildRow("asdad", false),
],
),
),
),

顺便说一句，在实现它之前，你需要使用wait。

Answer 2

希望这有帮助：

导入"package:flutter/material.dart"；

class Screen extends StatefulWidget {
@override
_ScreenState createState() => _ScreenState();
}
class _ScreenState extends State<Screen> {
bool _paddingVisible = false;
@override
void initState() {
super.initState();
Future.delayed(const Duration(seconds: 10), () {
// Check if mounted == true, because the screen might closed
// before 10 seconds pass
if (mounted) {
// Setting padding visibility to true after 10 seconds
setState(() {
_paddingVisible = true;
});
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: ListView(
children: [
// All your widgets
// When _paddingVisible becomes true it will be displayed
if (_paddingVisible) SizedBox(height: 10),
],
),
);
}
}