MMDrawerController error when reducing center screen alpha

Question

I am using MMDrawerController to create a sidebar in my ios app, i have succesfully implemented it, however i am trying to reduce the alpha of the center view when the sidebar displays, as you typically see on most apps with a similar feature, however i am getting the error

Type of expression is ambiguius without more context

Here is the code in my AppDelegate, the visualstateblock section is throwing the error

func buildNavigationDrawer()
{

    // Instantiate Main.storyboard
    let mainStoryBoard:UIStoryboard = UIStoryboard(name:"Main", bundle:nil)

    // Create View Controllers
    let mainPage:TabBarViewController = mainStoryBoard.instantiateViewController(withIdentifier: "TabBarViewController") as! TabBarViewController



    let rightSideMenu:HomeSideMenuViewController = mainStoryBoard.instantiateViewController(withIdentifier: "HomeSideMenuViewController") as! HomeSideMenuViewController



    // Wrap into Navigation controllers

    let rightSideMenuNav = UINavigationController(rootViewController:rightSideMenu)

    // Cerate MMDrawerController
    drawerContainer = MMDrawerController(center: mainPage, rightDrawerViewController: rightSideMenuNav)

    //drawerContainer!.openDrawerGestureModeMask = MMOpenDrawerGestureMode.PanningCenterView
    drawerContainer!.closeDrawerGestureModeMask = MMCloseDrawerGestureMode.panningCenterView

    drawerContainer!.setDrawerVisualStateBlock { (drawerContainer, rightSideMenuNav) in
        drawerContainer!.centerViewController.view.alpha = 0.3;
    }
    // Assign MMDrawerController to our window's root ViewController
    window?.rootViewController = drawerContainer

}

Thanks for your help

Answer 1

In setDrawerVisualStateBlock the returned MMDrawerController is not optional but still there is a force wrapper ! behind it

this is telling the compiler to take the optional value from the previous line (the one you created)

To solve this either change one of the variables name or use this:

drawerContainer?.setDrawerVisualStateBlock { $0.0.centerViewController.view.alpha = 0.3 }