在swift中改变uiimageview背景颜色

Question

![the result screenshot--][http://i.stack.imgur.com/4YRAJ.png] 我希望改变就像落后一样 ![enter image description here][http://i.stack.imgur.com/cBMsJ.png] 当幻灯片栏打开时，我想让幻灯片背后的背景更暗，覆盖UIimageview，但背景越来越暗，除了UIimageView。有没有办法变暗，包括图像？

   //
    //  ViewController.swift
    //  SideBarMenu
    //
    //  Created by Alexandre on 30/01/2015.
    //  Copyright (c) 2015 Alexandre. All rights reserved.
    //

import UIKit
import Social

class ViewController: UIViewController, SideBarDelegate {

    @IBOutlet weak var backgroundView: UIView!
    @IBOutlet weak var hedgeImage: UIImageView!

    func sideBarWillOpen() {
       /* let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
        let blurView = UIVisualEffectView(effect: blurEffect)
        blurView.frame = CGRectMake(0,0, 200, backgroundView.frame.size.height)
        backgroundView.addSubview(blurView)*/

        backgroundView.backgroundColor    = UIColor.grayColor()
        hedgeImage.backgroundColor = UIColor.grayColor()
    }

    func sideBarWillClose() {
        backgroundView.backgroundColor    = UIColor.whiteColor()
       // hegeImage.backgroundColor = UIColor.whiteColor()
    }

Answer 1

实现这一目标的一种方法是，您可以首先添加一个视图，并将该视图颜色设置为grayColor并在开始时将其隐藏，并将其alpha设置为0.8，当侧栏出现时显示该视图当侧栏隐藏时，你可以隐藏那个视图。

以下是您的简单示例代码：

import UIKit

class ViewController: UIViewController, sideBarDelegate {

    var sideBar : SideBar = SideBar()

    @IBOutlet weak var TransperentView: UIView!
    @IBOutlet weak var imageView: UIImageView!
    override func viewDidLoad() {
        super.viewDidLoad()
        TransperentView.hidden = true
        TransperentView.alpha = 0.8
        TransperentView.backgroundColor = UIColor.grayColor()
        sideBar = SideBar(sourceView: self.view, menuIteams: ["FirstIteam","SecondIteam","ThirdIteam","FourthIteam"])
        sideBar.delegate = self
    }

    func sideBarDidSelectButtonAtIndex(index: Int) {

        sideBar.showSideBar(false)
        TransperentView.hidden = true  //hide view
    }
    @IBAction func index(sender: AnyObject) {

        TransperentView.hidden = false
        sideBar.showSideBar(true)   //show view

    }
}

结果将是：

HERE是更多信息的示例项目。