Flutter(Dart代码)中如何获取应用的实时图标？

因为flutter_launcher_icons插件仅负责生成各平台的图标资源，并未提供Flutter层直接获取当前启动图标的API，所以需要通过**原生通道（MethodChannel）**实现跨平台的图标获取，以下是具体实现步骤：

Android 端实现 #

1. 编写原生方法获取图标
   在android/app/src/main/kotlin/[你的包名]/MainActivity.kt中添加代码：

   import android.content.pm.PackageManager
   import android.graphics.Bitmap
   import android.graphics.drawable.BitmapDrawable
   import io.flutter.embedding.android.FlutterActivity
   import io.flutter.embedding.engine.FlutterEngine
   import io.flutter.plugin.common.MethodChannel
   
   class MainActivity : FlutterActivity() {
       private val CHANNEL = "com.yourapp/icon_channel"
   
       override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
           super.configureFlutterEngine(flutterEngine)
           MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler { call, result ->
               if (call.method == "getAppIcon") {
                   try {
                       val packageManager = packageManager
                       val appIcon = packageManager.getApplicationIcon(packageName)
                       val bitmap = (appIcon as BitmapDrawable).bitmap
                       val stream = ByteArrayOutputStream()
                       bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream)
                       val byteArray = stream.toByteArray()
                       result.success(byteArray)
                   } catch (e: PackageManager.NameNotFoundException) {
                       result.error("NOT_FOUND", "App icon not found", e)
                   }
               } else {
                   result.notImplemented()
               }
           }
       }
   }
   

2. Flutter 端调用并展示
   在Flutter页面中通过MethodChannel调用原生方法，将字节流转为Image组件：

   import 'dart:typed_data';
   import 'package:flutter/services.dart';
   import 'package:flutter/widgets.dart';
   
   class AppIconDisplay extends StatefulWidget {
     const AppIconDisplay({super.key});
   
     @override
     State<AppIconDisplay> createState() => _AppIconDisplayState();
   }
   
   class _AppIconDisplayState extends State<AppIconDisplay> {
     final MethodChannel _channel = const MethodChannel('com.yourapp/icon_channel');
     Uint8List? _iconBytes;
   
     @override
     void initState() {
       super.initState();
       _fetchAppIcon();
     }
   
     Future<void> _fetchAppIcon() async {
       try {
         final Uint8List bytes = await _channel.invokeMethod('getAppIcon');
         setState(() {
           _iconBytes = bytes;
         });
       } on PlatformException catch (e) {
         print("Failed to get app icon: ${e.message}");
       }
     }
   
     @override
     Widget build(BuildContext context) {
       return _iconBytes != null
           ? Image.memory(_iconBytes!, width: 64, height: 64)
           : const CircularProgressIndicator();
     }
   }
   

iOS 端实现 #

1. 编写原生方法获取图标
   在ios/Runner/AppDelegate.swift中添加代码：

   import UIKit
   import Flutter
   
   @UIApplicationMain
   @objc class AppDelegate: FlutterAppDelegate {
     private let CHANNEL = "com.yourapp/icon_channel"
   
     override func application(
       _ application: UIApplication,
       didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
     ) -> Bool {
       let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
       let channel = FlutterMethodChannel(name: CHANNEL, binaryMessenger: controller.binaryMessenger)
       channel.setMethodCallHandler { [weak self] call, result in
         guard let self = self else { return }
         if call.method == "getAppIcon" {
           if let appIcon = UIApplication.shared.icon {
             if let data = appIcon.pngData() {
               result.success(data)
             } else {
               result.error("CONVERSION_FAILED", "Failed to convert icon to PNG", nil)
             }
           } else {
             result.error("NOT_FOUND", "App icon not found", nil)
           }
         } else {
           result.notImplemented()
         }
       }
       GeneratedPluginRegistrant.register(with: self)
       return super.application(application, didFinishLaunchingWithOptions: launchOptions)
     }
   }
   
   // 扩展UIApplication获取当前图标
   extension UIApplication {
     var icon: UIImage? {
       guard let icons = Bundle.main.infoDictionary?["CFBundleIcons"] as? [String: Any],
             let primaryIcons = icons["CFBundlePrimaryIcon"] as? [String: Any],
             let iconFiles = primaryIcons["CFBundleIconFiles"] as? [String],
             let lastIcon = iconFiles.last else { return nil }
       return UIImage(named: lastIcon)
     }
   }
   

2. Flutter 端复用代码
   Android端的Flutter代码可直接在iOS上使用，无需额外修改。

注意事项 #

• 若应用支持动态切换图标（如Android组件切换、iOSsetAlternateIconName），需在图标切换后重新调用_fetchAppIcon()刷新显示。
• 替换代码中的com.yourapp/icon_channel为自定义通道名称，避免冲突。
• 原生代码修改后需重新运行应用，热重载无法生效。

内容的提问来源于stack exchange，提问作者C. Lyman