IOS WebApp集成方式 黑屏，PDRCoreAppFrame,宽高都是0

我参考官方Demo（HBuilder-Integrate）在Xcode搭建了一个项目，使用 WebView集成方式 打开页面，正常，

使用 WebApp集成方式运行，界面黑屏，使用Reveal查看元素，发现 PDRCoreAppFrame 的度和高都是0，所以界面展示成黑屏，如果在Reveal中设置PDRCoreAppFrame的宽高后，界面元素又展示出来了，

采用 WebApp集成方式 时，为什么 PDRCoreAppFrame 布局的宽高是0？代码都是参考官方Demo项目代码

代码如下：

PDRCore *h5Engine = [PDRCore Instance];  
    [self setStatusBarStyle:h5Engine.settings.statusBarStyle];  
    // 获取当前是否是全屏  
    _isFullScreen = [UIApplication sharedApplication].statusBarHidden;  
    if ( _isFullScreen != h5Engine.settings.fullScreen ) {  
        _isFullScreen = h5Engine.settings.fullScreen;  
        if ( [self  respondsToSelector:@selector(setNeedsStatusBarAppearanceUpdate)] ) {  
            [self setNeedsStatusBarAppearanceUpdate];  
        } else {  
            [[UIApplication sharedApplication] setStatusBarHidden:_isFullScreen];  
        }  
    }  

    CGRect newRect = self.view.bounds;  
    if ( [self reserveStatusbarOffset] && [PTDeviceOSInfo systemVersion] > PTSystemVersion6Series) {  
        if ( !_isFullScreen ) {  
            newRect.origin.y += kStatusBarHeight;  
            newRect.size.height -= kStatusBarHeight;  
        }  
        _statusBarView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, newRect.size.width, kStatusBarHeight+1)];  
        _statusBarView.backgroundColor = h5Engine.settings.statusBarColor;  
        _statusBarView.autoresizingMask =  UIViewAutoresizingFlexibleWidth;  
        [self.view addSubview:_statusBarView];  
    }  
    _containerView = [[UIView alloc] initWithFrame:newRect];  
    _containerView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;  

    // 设置5+内核的Delegate，5+API在修改状态风格和应用是否全屏时会调用  
    h5Engine.coreDeleagete = self;  
    h5Engine.persentViewController = self;  

    [self.view addSubview:_containerView];  

    // 设置WebApp所在的目录，该目录下必须有mainfest.json  
    NSString* pWWWPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:@"Pandora/apps/MEBDcloudDemo/www"];  

    // 如果路径中包含中文，或Xcode工程的targets名为中文则需要对路径进行编码  
    //NSString* pWWWPath2 =  (NSString *)CFURLCreateStringByAddingPercentEscapes( kCFAllocatorDefault, (CFStringRef)pTempString, NULL, NULL,  kCFStringEncodingUTF8 );  

    // 用户在集成5+SDK时，需要在5+内核初始化时设置当前的集成方式，  
    // 请参考AppDelegate.m文件的- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions方法  
    if ([[PDRCore Instance] respondsToSelector:@selector(startAsAppClient)]) {  
        [[PDRCore Instance] performSelector:@selector(startAsAppClient)];  
    }  

    // 设置5+SDK运行的View  
    [[PDRCore Instance] setContainerView:_containerView];  

    // 传入参数可以在页面中通过plus.runtime.arguments参数获取  
    NSString* pArgus = @"id=plus.runtime.arguments";  
    // 启动该应用  
    pAppHandle = [[[PDRCore Instance] appManager] openAppAtLocation:pWWWPath withIndexPath:@"tab-webview-main.html" withArgs:pArgus withDelegate:nil];

运行效果：

Reveal界面元素布局：

通过Reveal调整界面元素布局：

模拟器运行效果：