添加Flutter到現(xiàn)有iOS的項目

創(chuàng)建iOS項目

如果你已經(jīng)有iOS項目如失，可以直接使用瘸恼。這里我們先創(chuàng)建一個空的iOS項目來模擬已有的項目，取名叫TestOne

創(chuàng)建Flutter模塊

進(jìn)入你的項目同一層目錄奥吩，假如你的項目是在...path1/path2/yourApp,那么你應(yīng)該進(jìn)入到path2目錄中

$ cd ...path1/path2/
$ flutter create -t module my_flutter

上面的命令會創(chuàng)建一個flutter的項目模塊，在flutter文件夾中有一個.ios的隱藏文件夾蕊梧，里面包裹了Cocoapods 和 Ruby 腳本霞赫。

完成后的項目目錄是這樣的：

將Flutter模塊作為依賴添加到主項目

添加Flutter需要使用cocoapods，如果你還沒有安裝肥矢，可以參考這里的詳細(xì)教程：安裝cocoapods

創(chuàng)建Podfile文件

如果你的工程已經(jīng)使用了Cocoapods端衰，就可以跳過此步驟。
安裝完成之后甘改，切換到工程的文件夾下：

cd 工程路徑

初始化pod的環(huán)境：

pod init

此時工程中會出現(xiàn)一個Podfile文件旅东，添加項目依賴的第三方庫就在這個文件中配置。

編輯Podfile文件添加最后兩行代碼：

# Uncomment the next line to define a global platform for your project
# platform :ios, '9.0'

target 'TestOne' do
  # Uncomment the next line if you're using Swift or would like to use dynamic frameworks
  # use_frameworks!

  # Pods for TestOne

  target 'TestOneTests' do
    inherit! :search_paths
    # Pods for testing
  end

  target 'TestOneUITests' do
    inherit! :search_paths
    # Pods for testing
  end

end

#新添加的代碼
flutter_application_path = '../my_flutter'
eval(File.read(File.join(flutter_application_path, '.ios', 'Flutter', 'podhelper.rb')), binding)

其中flutter_application_path代表你的flutter模塊路徑楼誓。
運(yùn)行

pod install

為編譯Dart 代碼添加build phase

打開iOS項目玉锌，選中TARGETTestOne項目的Build Phases選項，點擊左上角+號按鈕,選擇New Run Script Phase,將下面的shell腳本添加到輸入框中：

"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" build
"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" embed

如下圖所示：

然后需要編譯一下項目：Command + B疟羹。
如果你遇到了類似的這個問題：

FlutterPluginRegistrant/libFlutterPluginRegistrant.a(GeneratedPluginRegistrant.o)' does not contain bitcode.You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target.for architecture arm64

將EnableBitCode關(guān)掉就行主守，因為目前Flutter目前還不支持BitCode。

在主app中使用FlutterViewController

修改AppDelegate.h繼承自FlutterAppDelegate：

#import <UIKit/UIKit.h>
#import <Flutter/Flutter.h>

@interface AppDelegate : FlutterAppDelegate
@end

修改AppDelegate.m文件：

#import <FlutterPluginRegistrant/GeneratedPluginRegistrant.h> // Only if you have Flutter Plugins

#include "AppDelegate.h"

@implementation AppDelegate

// This override can be omitted if you do not have any Flutter Plugins.
- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [GeneratedPluginRegistrant registerWithRegistry:self];
  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

@end

如果你是Swift代碼榄融，可以修改AppDelegate.swift這個文件:

import UIKit
import Flutter
import FlutterPluginRegistrant // Only if you have Flutter Plugins.

@UIApplicationMain
class AppDelegate: FlutterAppDelegate {

  // Only if you have Flutter plugins.
  override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    GeneratedPluginRegistrant.register(with: self);
    return super.application(application, didFinishLaunchingWithOptions: launchOptions);
  }

}

但是如果你的delegate已經(jīng)是繼承于別的類的時候参淫，可以通過讓你的delegate實現(xiàn)FlutterAppLifeCycleProvider協(xié)議：

#import <Flutter/Flutter.h>
#import <UIKit/UIKit.h>
#import <FlutterPluginRegistrant/GeneratedPluginRegistrant.h> // Only if you have Flutter Plugins

@interface AppDelegate : UIResponder <UIApplicationDelegate, FlutterAppLifeCycleProvider>
@property (strong, nonatomic) UIWindow *window;
@end

然后生命周期方法應(yīng)該由FlutterPluginAppLifeCycleDelegate來代理：

@implementation AppDelegate
{
    FlutterPluginAppLifeCycleDelegate *_lifeCycleDelegate;
}

- (instancetype)init {
    if (self = [super init]) {
        _lifeCycleDelegate = [[FlutterPluginAppLifeCycleDelegate alloc] init];
    }
    return self;
}

- (BOOL)application:(UIApplication*)application
didFinishLaunchingWithOptions:(NSDictionary*)launchOptions {
    [GeneratedPluginRegistrant registerWithRegistry:self]; // Only if you are using Flutter plugins.
    return [_lifeCycleDelegate application:application didFinishLaunchingWithOptions:launchOptions];
}

// Returns the key window's rootViewController, if it's a FlutterViewController.
// Otherwise, returns nil.
- (FlutterViewController*)rootFlutterViewController {
    UIViewController* viewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    if ([viewController isKindOfClass:[FlutterViewController class]]) {
        return (FlutterViewController*)viewController;
    }
    return nil;
}

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
    [super touchesBegan:touches withEvent:event];
    
    // Pass status bar taps to key window Flutter rootViewController.
    if (self.rootFlutterViewController != nil) {
        [self.rootFlutterViewController handleStatusBarTouches:event];
    }
}

- (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];
}
@end

使用FlutterViewController

在ViewController.m中添加測試代碼：

#import <Flutter/Flutter.h>
#import "ViewController.h"

@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button addTarget:self
               action:@selector(handleButtonAction)
     forControlEvents:UIControlEventTouchUpInside];
    [button setTitle:@"Press me" forState:UIControlStateNormal];
    [button setBackgroundColor:[UIColor blueColor]];
    button.frame = CGRectMake(80.0, 210.0, 160.0, 40.0);
    [self.view addSubview:button];
}

- (void)handleButtonAction {
    FlutterViewController* flutterViewController = [[FlutterViewController alloc] init];
    [self presentViewController:flutterViewController animated:false completion:nil];
}
@end

swift版：

import UIKit
import Flutter

class ViewController: UIViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    let button = UIButton(type:UIButtonType.custom)
    button.addTarget(self, action: #selector(handleButtonAction), for: .touchUpInside)
    button.setTitle("Press me", for: UIControlState.normal)
    button.frame = CGRect(x: 80.0, y: 210.0, width: 160.0, height: 40.0)
    button.backgroundColor = UIColor.blue
    self.view.addSubview(button)
  }

  @objc func handleButtonAction() {
    let flutterViewController = FlutterViewController()
    self.present(flutterViewController, animated: false, completion: nil)
  }
}

現(xiàn)在運(yùn)行代碼，點擊按鈕愧杯，就能看到一個全屏的Flutter界面在你的app上涎才。
你也可以設(shè)置路由跳轉(zhuǎn)的別的組件上：

• Objective-C:

[flutterViewController setInitialRoute:@"route1"];

• Swift：

flutterViewController.setInitialRoute("route1")

你可以在展示FlutterViewController之前，在Dart代碼中使用SystemNavigator.pop()將其彈出展示棧（就像iOS原生那樣）力九。

例子截圖：

點擊按鈕跳轉(zhuǎn)到flutter頁面：

使用熱重載的方法

熱重載指的是不用重新啟動就看到修改后的效果耍铜，類似web網(wǎng)頁開發(fā)時保存就看到效果的方式。
進(jìn)入flutter模塊跌前，執(zhí)行命令：

$ cd some/path/my_flutter
$ flutter attach
Waiting for a connection from Flutter on iPhone XR...

接下來在xcode中啟動你的app棕兼，進(jìn)入到flutter的頁面，此時你應(yīng)該在控制臺（終端）看到如下信息：

<table><tr><td bgcolor=#D1EEEE>?? To hot reload changes while running, press "r". To hot restart (and rebuild state), press "R".
An Observatory debugger and profiler on Android SDK built for x86 is available at: http://127.0.0.1:61513/
For a more detailed help message, press "h". To detach, press "d"; to quit, press "q".
</td></tr></table>

你可以在my_flutter中編輯Dart code抵乓，然后在終端輸入r來使用熱重載伴挚。你也可以在瀏覽器中輸入上面的URL來查看斷點、分析內(nèi)存和其他的調(diào)試任務(wù)灾炭。

歡迎繼續(xù)學(xué)習(xí)相關(guān)的其他系列教程茎芋，關(guān)注我們TryEnough