1、启动时【目的是为了react native跳转到原生时使用原来的RCTBridge，react native就不行重新加载了】
_bridge= [[RCTBridgealloc]initWithDelegate:self launchOptions:launchOptions];
RCTRootView*rootView = [[RCTRootViewalloc]initWithBridge:_bridge moduleName:@"GroupChatApp" initialProperties:initProps];
self.window= [[UIWindowalloc]initWithFrame:[UIScreenmainScreen].bounds];
UIViewController*rootViewController = [UIViewControllernew];
rootViewController.view= rootView;
self.navigation= [[UINavigationControlleralloc]initWithRootViewController:rootViewController];
self.navigation.navigationBarHidden=YES;
self.window.rootViewController=self.navigation;
