FlutterBoost 实现Flutter页面内嵌iOS view

在使用Flutter混合开发中会遇到一些原生比Flutter优秀的控件，不想使用Flutter的控件，想在Flutter中使用原生控件。这时就会用到 Flutter页面中内嵌 原生view，这里简单介绍一个 内嵌 iOS 的view。

注：这里使用了 FlutterBoost。网上大部分都是代码执行不起来，本案例起码可以正常使用。

• 原生部分
  这里开始在原生部分进行处理
• 自定义 view FlutterIosTextLabel

#import <Foundation/Foundation.h>
#import <Flutter/Flutter.h>NS_ASSUME_NONNULL_BEGIN@interface FlutterIosTextLabel : NSObject<FlutterPlatformView>@property (nonatomic, strong) UILabel *label;- (instancetype)initWithFrame:(CGRect)frameviewIdentifier:(int64_t)viewIdarguments:(id _Nullable)argsbinaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;@endNS_ASSUME_NONNULL_END

#import "FlutterIosTextLabel.h"@implementation FlutterIosTextLabel//在这里只是创建了一个UILabel
- (instancetype)initWithFrame:(CGRect)frame viewIdentifier:(int64_t)viewId arguments:(id _Nullable)args binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {if (self = [super init]) {self.label = [UILabel new];self.label.backgroundColor = [UIColor yellowColor];self.label.textColor = [UIColor redColor];self.label.textAlignment = NSTextAlignmentCenter;self.label.numberOfLines = 0;NSDictionary *dict = (NSDictionary *)args;NSString *textValue = dict[@"content"];self.label.text = [NSString stringWithFormat:@"我是iOSView \n在显示：%@", textValue];}return self;
}- (nonnull UIView *)view {return self.label;
}@end

• 创建 FlutterIosTextLabelFactory

#import <Foundation/Foundation.h>
#import <Flutter/Flutter.h>NS_ASSUME_NONNULL_BEGIN@interface FlutterIosTextLabelFactory : NSObject<FlutterPlatformViewFactory>- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;@endNS_ASSUME_NONNULL_END

#import "FlutterIosTextLabelFactory.h"
#import "FlutterIosTextLabel.h"@implementation FlutterIosTextLabelFactory
{NSObject<FlutterBinaryMessenger> *_messenger;
}- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {self = [super init];if (self) {_messenger = messenger;}return self;
}- (NSObject<FlutterPlatformView>*)createWithFrame:(CGRect)frame viewIdentifier:(int64_t)viewId arguments:(id _Nullable)args {return [[FlutterIosTextLabel alloc] initWithFrame:frame viewIdentifier:viewId arguments:args binaryMessenger:_messenger];
}-(NSObject<FlutterMessageCodec> *)createArgsCodec{return [FlutterStandardMessageCodec sharedInstance];
}

• 创建 FlutterIosTextLabelPlugin

#import <Foundation/Foundation.h>
#import <Flutter/Flutter.h>NS_ASSUME_NONNULL_BEGIN@interface FlutterIosTextLabelPlugin : NSObject<FlutterPlugin>
+ (void)registerWithRegistrar:(nonnull NSObject<FlutterPluginRegistrar> *)registrar;
@endNS_ASSUME_NONNULL_END

#import "FlutterIosTextLabelPlugin.h"
#import "FlutterIosTextLabelFactory.h"@implementation FlutterIosTextLabelPlugin+ (void)registerWithRegistrar:(nonnull NSObject<FlutterPluginRegistrar> *)registrar {//注册插件//注册 FlutterIosTextLabelFactory//custom_platform_view 为flutter 调用此  textLabel 的标识[registrar registerViewFactory:[[FlutterIosTextLabelFactory alloc] initWithMessenger:registrar.messenger] withId:@"custom_platform_view"];
}
@end

到此原生已经集成完成一半，重点是接下来部分。

在 AppDelegate 中集成使用
修改AppDelegate.h：修改继承为FlutterAppDelegate，并删除window属性，因为FlutterAppDelegate中已经自带window属性

#import <UIKit/UIKit.h>
#import <Flutter/Flutter.h>@interface AppDelegate : FlutterAppDelegate
@end

在AppDelegate.m中引入相关头文件

#import "FlutterIosTextLabel.h"
#import "GeneratedPluginRegistrant.h"
#import "FlutterIosTextLabelPlugin.h"

在AppDelegate.m中注册插件，在引入 flutter_boost的情况下，需要等 flutter_boost初始化完成后，用FlutterEngine对插件进行初始化。

@interface AppDelegate ()@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {HYFlutterBoostDelegate* delegate = [[HYFlutterBoostDelegate alloc]init];self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];self.window.backgroundColor = [UIColor whiteColor];HYTabBarController *tab = [[HYTabBarController alloc]init];self.window.rootViewController = tab;[self.window makeKeyAndVisible];[FlutterBoost.instance setup:application delegate:delegate callback:^(FlutterEngine *engine) {NSLog(@"FlutterBoost 开始操作");// 使用 MethodChannel[HYFlutterNavChannel start];[HYFlutterCommonChannel start];// 初始化Flutter内嵌iOSView插件
//        NSObject<FlutterPluginRegistrar> *registrar = [engine registrarForPlugin:@"custom_platform_view_plugin"];
//        FlutterIosTextLabelFactory *factory = [[FlutterIosTextLabelFactory alloc] initWithMessenger:registrar.messenger];
//        [registrar registerViewFactory:factory withId:@"custom_platform_view"];// 升级处理NSObject<FlutterPluginRegistrar> *registrar = [engine registrarForPlugin:@"custom_platform_view_plugin"];[FlutterIosTextLabelPlugin registerWithRegistrar:registrar];}];return YES;
}@end

到此原生集成完毕，接下来在 Flutter中进行集成

• Flutter 部分

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';class CMNativePage extends StatelessWidget {const CMNativePage({Key? key}) : super(key: key);@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: const Text("详情"),),body: const Center(child: IOSCompositionWidget(),),);}
}class IOSCompositionWidget extends StatelessWidget {const IOSCompositionWidget({super.key});@overrideWidget build(BuildContext context) {// This is used in the platform side to register the view.const String viewType = 'custom_platform_view';// Pass parameters to the platform side.final Map<String, dynamic> creationParams = {'content': 'Flutter传给原生iOSView的参数'};return UiKitView(viewType: viewType,creationParams: creationParams,creationParamsCodec: const StandardMessageCodec(),);}
}

注册路由

static const String nativaPage = '/nativaPage';

 nativaPage: (settings, uniqued) {return MaterialPageRoute(settings: settings,builder: (_) {return const CMNativePage();});},

在Flutter地方使用

 TextButton(child: const Text("加载原生控件"),onPressed: () {BoostNavigator.instance.push(HYRouter.nativaPage, arguments: {"home": "home页面传递数值"});// showBottomWidget(context, const CMNativePage());},),

到此Flutter中也完成集成。
如果想要某些弹出样式，自己再进行处理。这里只是简单的使用Flutter 内嵌 iOS原生view。

注意事项：

1. FlutterIosTextLabelFactory中的createArgsCodec方法一定不能遗漏，否则会导致传值不成功。类型也一定要和Dart部分的native.dart->IOSCompositionWidget-> UiKitView-> creationParamsCodec保持一致。否则会导致崩溃。
2. 使用官方文档中的写法是没有问题，但是本案例中使用了flutter_boost，再跟着官网集成就会出现问题。需要更flutter_boost初始化完成，再对FlutterEngine对插件进行初始化。
3. 其中withId:xxx，xxx代表控件的ID，需要和Dart部分的IOSCompositionWidget中的viewType保持一致。命名为：custom_platform_view。
4. 其中registrarForPlugin:xxx，xxx代表插件的ID。命名为：custom_platform_view_plugin。