Unity项目嵌入现有iOS项目的方法

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UnityAppController * unityController;
@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UIWindow * unityWindow;

- (void)showUnityWindow;
- (void)hideUnityWindow;


@end

#import "AppDelegate.h"
#import "ViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

- (UIWindow *)unityWindow {
    return UnityGetMainWindow();
}

- (void)showUnityWindow {
    
    UIButton * btn = [UIButton buttonWithType:UIButtonTypeSystem];
    [btn setTitle:@"返回iOS世界" forState:UIControlStateNormal];
    [btn setFrame:CGRectMake(100, 100, 100, 40)];
    [btn addTarget:self action:@selector(hideUnityWindow) forControlEvents:UIControlEventTouchUpInside];
    [self.unityWindow addSubview:btn];
    
    [self.unityWindow makeKeyAndVisible];
}

- (void)hideUnityWindow {
    [self.window makeKeyAndVisible];
}


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.window.backgroundColor = [UIColor whiteColor];
    UINavigationController * nav = [[UINavigationController alloc] initWithRootViewController:[[ViewController alloc] init]];
    
    self.window.rootViewController = nav;
    self.unityController = [[UnityAppController alloc] init];
    [self.unityController application:application didFinishLaunchingWithOptions:launchOptions];
    [self.window makeKeyAndVisible];
    
    return YES;
}


- (void)applicationWillResignActive:(UIApplication *)application {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    [_unityController applicationWillResignActive:application];
}


- (void)applicationDidEnterBackground:(UIApplication *)application {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    [_unityController applicationDidEnterBackground:application];
}


- (void)applicationWillEnterForeground:(UIApplication *)application {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    [_unityController applicationWillEnterForeground:application];
}


- (void)applicationDidBecomeActive:(UIApplication *)application {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    [_unityController applicationDidBecomeActive:application];
}


- (void)applicationWillTerminate:(UIApplication *)application {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    [_unityController applicationWillTerminate:application];
}

@end

#import "AppDelegate.h"

inline UnityAppController*  GetAppController()
{
    AppDelegate * delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    return delegate.unityController;
//    return (UnityAppController*)[UIApplication sharedApplication].delegate;
}

[(AppDelegate *)[UIApplication sharedApplication].delegate showUnityWindow];
UnityPause(false);

[(AppDelegate*)[UIApplication sharedApplication].delegate  hideUnityWindow];
UnityPause(true);

1，报错:libil2cpp/include/codegen/il2cpp-codegen.h:368:1: Control may reach end of non-void function 
添加 return NULL;
2，编译时遇到Permission denied错误的是因为当前开发账号对项目目录没有权限执行MapFileParser.sh
解决方法：chmod +x   /Users/......./MapFileParser.sh （MapFileParser.sh所在的目录）
3，clang: error: no such file or directory: 'CoreMotion'，注意Other Linker Flags的导入的顺序
4，加了extern "c",却不认识，一直报少“（”，在Build Settings选项中找到Compile Sources As这项设置成Objective-C++ 就解决问题了