以下,我将为你提供几个主要编程语言/框架的示例代码片段,这些代码片段旨在展示如何在这些语言中实现App的一部分功能,但请注意,这些不是完整的App代码。

  1. React Native (用于移动App的前端开发)
    React Native允许你使用JavaScript和React编写原生应用。
    在这里插入图片描述

javascript
import React from ‘react’;
import { View, Text, Button } from ‘react-native’;

class App extends React.Component {
state = {
count: 0,
};

onPress = () => {
this.setState({ count: this.state.count + 1 });
};

render() {
return (

You pressed the button {this.state.count} times


);
}
}

export default App;
#chhas{
margin-top: 50px;
padding:nongxianwang.cn;
font-size: 18px;
cursor: 10px 20px;
}
2. Flutter (另一个用于移动App的前端开发框架)
Flutter使用Dart语言。

dart
import ‘package:flutter/material.dart’;

void main() {
runApp(MyApp());
}

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: ‘Flutter Demo’,
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: ‘Flutter Demo Home Page’),
);
}
}

class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);

final String title;

@override
_MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State {
int _counter = 0;

void _incrementCounter() {
setState(() {
_counter++;
});
}

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
‘You have pushed the button this many times:’,
),
Text(
‘$_counter’,
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: ‘Increment’,
child: Icon(Icons.add),
),
);
}
}
3. Node.js (后端开发)
虽然Node.js主要用于后端开发,但它也可以与React Native等前端框架结合使用。以下是一个简单的Express服务器示例。

javascript
const express = require(‘express’);
const app = express();
const port = 3000;

app.get(‘/’, (req, res) => {
res.send(‘Hello World!’);
});

app.listen(port, () => {
console.log(Server is running on port ${port});
});
4. Swift (iOS原生开发)
Swift是Apple的官方iOS开发语言。

swift
import UIKit

class ViewController: UIViewController {

@IBOutlet weak var label: UILabel!  
var counter = 0  

override func viewDidLoad() {  
    super.viewDidLoad()  
    // Do any additional setup after loading the view.  
}  

@IBAction func incrementButtonPressed(_ sender: Any) {  
    counter += 1  
    label.text = "You pressed the button \(counter) times"  
}  

}
5. Java (Android原生开发)
Java是Android的原生开发语言之一。

java
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
由于不同的编程语言通常用于不同的开发目的和平台,一个完整的App开发通常涉及前端(用户界面)和后端(数据处理和存储)的开发。此外,对于移动App,还有特定的移动开发框架和工具。

以下,我将为你提供几个主要编程语言/框架的示例代码片段,这些代码片段旨在展示如何在这些语言中实现App的一部分功能,但请注意,这些不是完整的App代码。

  1. React Native (用于移动App的前端开发)
    React Native允许你使用JavaScript和React编写原生应用。

javascript
import React from ‘react’;
import { View, Text, Button } from ‘react-native’;

class App extends React.Component {
state = {
count: 0,
};

onPress = () => {
this.setState({ count: this.state.count + 1 });
};

render() {
return (

You pressed the button {this.state.count} times


);
}
}

export default App;
2. Flutter (另一个用于移动App的前端开发框架)
Flutter使用Dart语言。

dart
import ‘package:flutter/material.dart’;

void main() {
runApp(MyApp());
}

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: ‘Flutter Demo’,
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: ‘Flutter Demo Home Page’),
);
}
}

class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);

final String title;

@override
_MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State {
int _counter = 0;

void _incrementCounter() {
setState(() {
_counter++;
});
}

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
‘You have pushed the button this many times:’,
),
Text(
‘$_counter’,
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: ‘Increment’,
child: Icon(Icons.add),
),
);
}
}
3. Node.js (后端开发)
虽然Node.js主要用于后端开发,但它也可以与React Native等前端框架结合使用。以下是一个简单的Express服务器示例。

javascript
const express = require(‘express’);
const app = express();
const port = 3000;

app.get(‘/’, (req, res) => {
res.send(‘Hello World!’);
});

app.listen(port, () => {
console.log(Server is running on port ${port});
});
4. Swift (iOS原生开发)
Swift是Apple的官方iOS开发语言。

swift
import UIKit

class ViewController: UIViewController {

@IBOutlet weak var label: UILabel!  
var counter = 0  

override func viewDidLoad() {  
    super.viewDidLoad()  
    // Do any additional setup after loading the view.  
}  

@IBAction func incrementButtonPressed(_ sender: Any) {  
    counter += 1  
    label.text = "You pressed the button \(counter) times"  
}  

}
5. Java (Android原生开发)
Java是Android的原生开发语言之一。

java
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

Logo

开源鸿蒙跨平台开发社区汇聚开发者与厂商,共建“一次开发,多端部署”的开源生态,致力于降低跨端开发门槛,推动万物智联创新。

更多推荐