如何从 Flutter 调用 HTTP API？

Question

我需要在我的 Flutter 应用程序中实现从 clickatell.com 发送短信的一种方式，他们有 HTTP API。在实现之前，我想测试一下来自flutter的API，不知道如何创建HTTP请求。当我从我的浏览器尝试 HTTP API 时，它有效，但在 Flutter 中无效。 HTTP 看起来像这样： "https://platform.clickatell.com/messages/http/send?apiKey=FeKBZwZ3T2q3BNcjsJvHCA==&to=12345678&content=Test+message+text"

我试图在 flutter 中使用 HTTP 创建 post，并编码 JSON，因为我在文档中发现它是 JSON，但它不起作用. 此外，我在 android 清单文件中添加了互联网权限，它看起来像这样：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.darkomilosevic.sms_test">
    <uses-permission android:name="android.permission.INTERNET" />
   <application
        android:label="SMS test"
        android:name="${applicationName}"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
</manifest>

我的飞镖代码如下所示：

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'SMS test',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Send SMS'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;
  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final String phoneNumber = "12345678";
  final String apiKey = "FeKBZwZ3T2q3BNcjsJvHCA";
  final String smsSubject = "Test sms:";

  Future<http.Response> sendSMS(String messageText) async {
    var url = Uri.parse('https://platform.clickatell.com/messages/http/send');
    return await http.post(url,
        headers: <String, String>{
          'Content-Type': 'application/json; charset=UTF-8'
        },
        body: jsonEncode(<String, String>{
          'apiKey': apiKey,
          'to': phoneNumber,
          'content': 'test+$smsSubject+$messageText'
        }));
  }

  Future sendTextMessage() async {
    await sendSMS(myController.text);
    setState(() {
      myController.clear();
    });
  }

  final myController = TextEditingController();
  @override
  void dispose() {
    myController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
                controller: myController, enableInteractiveSelection: true)
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: sendTextMessage,
        tooltip: 'Send',
        child: const Icon(Icons.sms),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Answer 1

只需尝试 GET 请求。我认为您的 API 不支持 POST 请求。我还检查了 POST 请求，但它给出了 405 错误。

void _onPressed() async {
try {
  final response = await http.get(
    Uri.parse(
        'https://platform.clickatell.com/messages/http/send?apiKey=FeKBZwZ3T2q3BNcjsJvHCA==&to=12345678&content=Test+message+text'),
  );
  final responseData = jsonDecode(response.body);
  log(responseData.toString());
} catch (e) {
  log(e.toString());
}}

如何从 Flutter 调用 HTTP API？

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