Flutter教程Channel调用iOS原生代码

如何在Flutter中通过MethodChannel调用iOS原生代码？我在尝试与iOS原生功能交互时遇到了困难，具体步骤应该怎么操作？

需要传递参数给原生代码时，应该如何正确编码和解码数据？iOS端和Flutter端的代码应该如何对应？

如果调用过程中出现错误，比如channel未注册或者方法未实现，应该如何排查和解决？有没有完整的示例代码可以参考？

3 回复

在Flutter中通过Platform Channels可以调用iOS原生代码。首先，在Flutter端创建MethodChannel对象：

const platform = MethodChannel('com.example/native');

然后定义一个方法来调用原生代码：

Future<void> callNativeCode() async {
  try {
    final String result = await platform.invokeMethod('getNativeData');
    print("Received from iOS: $result");
  } on PlatformException catch (e) {
    print("Failed: '${e.message}'");
  }
}

在iOS端，打开AppDelegate.swift文件，在application(_:didFinishLaunchingWithOptions:)方法里注册通道：

let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
let channel = FlutterMethodChannel(name: "com.example/native", binaryMessenger: controller.binaryMessenger)
channel.setMethodCallHandler({
  (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
  if call.method == "getNativeData" {
    result("Hello from iOS")
  } else {
    result(FlutterMethodNotImplemented)
  }
})

这样就完成了Flutter调用iOS原生代码的设置。记得在pubspec.yaml中添加权限和依赖项。

更多关于Flutter教程Channel调用iOS原生代码的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html


在Flutter中通过MethodChannel调用iOS原生代码是一种常见的需求。首先，在iOS端创建一个Flutter项目后，在AppDelegate中初始化MethodChannel：

FlutterViewController *controller = (FlutterViewController *)self.window.rootViewController;
NSString *channelName = @"com.example/native";
FlutterMethodChannel *channel = [FlutterMethodChannel methodChannelWithName:channelName
                                                                  binaryMessenger:controller];

然后实现方法处理函数：

[channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
    if ([@"getDeviceModel" isEqualToString:call.method]) {
        NSString *deviceModel = [[UIDevice currentDevice] model];
        result(deviceModel);
    } else {
        result(FlutterMethodNotImplemented);
    }
}];

在Flutter端通过MethodChannel调用：

final platform = MethodChannel('com.example/native');

Future<void> getDeviceModel() async {
  String deviceModel;
  try {
    deviceModel = await platform.invokeMethod('getDeviceModel');
  } catch (e) {
    print(e.toString());
  }
}

确保两端方法名一致，iOS端处理完返回结果后，会通过result()传递到Flutter端。

Flutter与iOS原生代码交互方法

在Flutter中调用iOS原生代码通常通过MethodChannel实现，以下是基本步骤：

1. 在Flutter中设置MethodChannel

import 'package:flutter/services.dart';

// 创建MethodChannel
const platform = MethodChannel('com.example/app');

// 调用原生方法示例
Future<void> callNativeMethod() async {
  try {
    final String result = await platform.invokeMethod('getNativeData');
    print('Received from native: $result');
  } on PlatformException catch (e) {
    print("Failed to invoke method: '${e.message}'.");
  }
}

2. 在iOS端设置接收方法

在AppDelegate.swift中：

import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
    
    // 设置MethodChannel
    let channel = FlutterMethodChannel(name: "com.example/app",
                                      binaryMessenger: controller.binaryMessenger)
    
    channel.setMethodCallHandler({
      (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
      
      // 根据方法名处理不同调用
      if call.method == "getNativeData" {
        // 返回数据给Flutter
        result("Hello from iOS!")
      } else {
        result(FlutterMethodNotImplemented)
      }
    })
    
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

关键点说明

  1. Channel名称：Flutter和iOS端的channel名称必须一致
  2. 数据类型：支持基本数据类型、List和Map
  3. 异步处理：iOS端的回调是异步的，需要调用FlutterResult
  4. 错误处理：双方都需要做好错误处理

这种方法可以实现双向通信，Flutter可以调用iOS原生代码，iOS也可以主动发送消息给Flutter。

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