Flutter-現有iOS工程引入Flutter

前言

Flutter 是一個頗有潛力的框架，可是目前使用Flutter的APP並不算不少，相關資料並不豐富，介紹現有工程引入Flutter的相關文章也比較少。項目從零開始，引入Flutter操做比較簡單，可是現有工程引入Flutter 須要費不少精力和時間，這裏是我在完成現有iOS工程引入Flutter後寫的一次總結文章。

Flutter 環境搭建

首先是要搭建Flutter環境，以前也寫了一篇相關文章搭建Flutter-iOS開發環境，能夠參考一下 能夠去官網查看：github.com/flutter/flu… 比較簡單，這裏不作贅述。

現有iOS工程引入Flutter

1、創建Flutter module

首先創建flutter module，主要是用於獲取改flutter app中的Generated.xcconfig和framework

cd some/path/ $ flutter create -t module my_flutter 複製代碼

也能夠用

flutter create app
複製代碼

創建flutter app，flutter app中也有Generated.xcconfig和framework

2、新建配置文件

根據官網，須要在工程中創建三個配置文件： Flutter.xcconfig 、Debug.xcconfig、Release.xcconfig 在XCode工程對應目錄，右擊，選擇新建文件（New File），選中建立xcconfig文件，如圖：

在Flutter.xcconfig中填寫：

//這裏填寫前面創建的flutter module 的Generated.xcconfig的路徑
#include "../../my_flutter/.ios/Flutter/Generated.xcconfig" ENABLE_BITCODE=NO 複製代碼

在 Debug.xcconfig中填寫:

#include "../Flutter/Flutter.xcconfig" 複製代碼

在 Release.xcconfig中填寫:

#include "../Flutter/Flutter.xcconfig" FLUTTER_BUILD_MODE=release 複製代碼

若是工程中用cocoapods管理，須要在 Debug.xcconfig和Release.xcconfig添加pod的路徑：

例如 Release.xcconfig中

#include "Flutter.xcconfig" #include "工程路徑/Pods/Target Support Files/******.release.xcconfig"//pod路徑 FLUTTER_BUILD_MODE=release 複製代碼

在準備好這些xcconfig文件後，須要到XCode工程PROJECT（注意是PROJECT,不是Target）中的Configuration選項裏，將對應的target選擇成前面的xcconfig文件，Debug用Debug.xcconfig, Release用 Release.xcconfig

注意：進行Archive打包的時候，不管是Debug包仍是Release包，須要切換到Release.xcconfig，否則會報錯。

3、爲編譯Dart引入相關build phase

在工程的Build Phase中新建一個Run Script,用於編譯時運行腳本， 創建方法如圖：

創建Run Script後，須要移動其對應的位置，須要在Target dependencies以後，若是用cocoapods管理工程須要在，Check Pods Manifest.lock以後：

在腳本框中，填入如下代碼，用於引進Flutter中的xcode_backend腳本：

"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" build 複製代碼

如圖：

4、生成和添加Framework

完成前面的配置後，即可以在XCode對工程進行編譯build (Command+B)，在提示「 Build Success 」 後，在iOS工程文件夾中會生成一個Flutter文件夾，將其加入工程目錄中,建議和剛纔xcconfig所在目錄並列，

右鍵項目目錄 ，選擇 Add Files to 'xxx' ，Options選Create groups，添加編譯生成的Flutter文件夾。須要注意可是：Flutter目錄下有個flutter_assets文件，不能使用Create groups的方式添加，只能用Creat folder references的Options， 不然Flutter頁面會空白渲染不出來。能夠刪了flutter_assets在用Creat folder references從新添加。

在添加完Flutter 文件夾以後，去Embeded Binaries中添加App.framework和Flutter.framework

5、AppDelegate改造

Flutter須要和APP進行交互，須要對AppDelegate 進行改造：

AppDelegate.h文件中：

#import <Flutter/Flutter.h> @interface AppDelegate : FlutterAppDelegate <UIApplicationDelegate, FlutterAppLifeCycleProvider> @end 複製代碼

AppDelegate.m 文件中：

#import "AppDelegate.h" @interface AppDelegate () @end @implementation AppDelegate { FlutterPluginAppLifeCycleDelegate *_lifeCycleDelegate; } - (instancetype)init { if (self = [super init]) { _lifeCycleDelegate = [[FlutterPluginAppLifeCycleDelegate alloc] init]; } return self; } - (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions { return [_lifeCycleDelegate application:application didFinishLaunchingWithOptions:launchOptions]; } - (void)applicationDidEnterBackground:(UIApplication*)application { [_lifeCycleDelegate applicationDidEnterBackground:application]; } - (void)applicationWillEnterForeground:(UIApplication*)application { [_lifeCycleDelegate applicationWillEnterForeground:application]; } - (void)applicationWillResignActive:(UIApplication*)application { [_lifeCycleDelegate applicationWillResignActive:application]; } - (void)applicationDidBecomeActive:(UIApplication*)application { [_lifeCycleDelegate applicationDidBecomeActive:application]; } - (void)applicationWillTerminate:(UIApplication*)application { [_lifeCycleDelegate applicationWillTerminate:application]; } - (void)application:(UIApplication*)application didRegisterUserNotificationSettings:(UIUserNotificationSettings*)notificationSettings { [_lifeCycleDelegate application:application didRegisterUserNotificationSettings:notificationSettings]; } - (void)application:(UIApplication*)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData*)deviceToken { [_lifeCycleDelegate application:application didRegisterForRemoteNotificationsWithDeviceToken:deviceToken]; } - (void)application:(UIApplication*)application didReceiveRemoteNotification:(NSDictionary*)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler { [_lifeCycleDelegate application:application didReceiveRemoteNotification:userInfo fetchCompletionHandler:completionHandler]; } - (BOOL)application:(UIApplication*)application openURL:(NSURL*)url options:(NSDictionary<UIApplicationOpenURLOptionsKey, id>*)options { return [_lifeCycleDelegate application:application openURL:url options:options]; } - (BOOL)application:(UIApplication*)application handleOpenURL:(NSURL*)url { return [_lifeCycleDelegate application:application handleOpenURL:url]; } - (BOOL)application:(UIApplication*)application openURL:(NSURL*)url sourceApplication:(NSString*)sourceApplication annotation:(id)annotation { return [_lifeCycleDelegate application:application openURL:url sourceApplication:sourceApplication annotation:annotation]; } - (void)application:(UIApplication*)application performActionForShortcutItem:(UIApplicationShortcutItem*)shortcutItem completionHandler:(void (^)(BOOL succeeded))completionHandler NS_AVAILABLE_IOS(9_0) { [_lifeCycleDelegate application:application performActionForShortcutItem:shortcutItem completionHandler:completionHandler]; } - (void)application:(UIApplication*)application handleEventsForBackgroundURLSession:(nonnull NSString*)identifier completionHandler:(nonnull void (^)(void))completionHandler { [_lifeCycleDelegate application:application handleEventsForBackgroundURLSession:identifier completionHandler:completionHandler]; } - (void)application:(UIApplication*)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler { [_lifeCycleDelegate application:application performFetchWithCompletionHandler:completionHandler]; } - (void)addApplicationLifeCycleDelegate:(NSObject<FlutterPlugin>*)delegate { [_lifeCycleDelegate addDelegate:delegate]; } 複製代碼

6、新建FlutterViewController

主要配置基本上已經完成，只要在main.dart實現Flutter的業務代碼便可

在原有工程中 ，創建FlutterViewController來承載 main.dart實現的Flutter頁面，如：

self.flutterViewController = [[FlutterViewController alloc] initWithProject:nil nibName:nil bundle:nil];
    [self.navigationController pushViewController:self.flutterViewController animated:YES];
複製代碼

後語

到這裏現有iOS工程引入Flutter的工做就完成了，一些細節上的修改須要根據場景進行修改，例如Flutter和Native的數據通訊等。