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首页导航栏按钮

• 用户登录成功后，显示 搜索好友 和 更多操作 图片按钮

• 在 viewDidLoad 添加 setNavigationBar 方法

• 设置导航栏 左右按钮

  • 在 setNavigationBar 添加:

    private func setupNavigation() -> Void {
      // 设置导航栏左按钮
      let leftButton = UIButton()
      leftButton.setBackgroundImage(UIImage(named: "navigationbar_friendsearch"), for: UIControlState.normal)
      leftButton.setBackgroundImage(UIImage(named: "navigationbar_friendsearch_highlighted"), for: UIControlState.highlighted)
      leftButton.sizeToFit()
      navigationItem.leftBarButtonItem = UIBarButtonItem(customView: leftButton)
      // 设置导航栏右按钮
      let rightButton = UIButton()
      rightButton.setBackgroundImage(UIImage(named: "navigationbar_pop"), for: UIControlState.normal)
      rightButton.setBackgroundImage(UIImage(named: "navigationbar_pop_highlighted"), for: UIControlState.highlighted)
      rightButton.sizeToFit()
      navigationItem.rightBarButtonItem = UIBarButtonItem(customView: rightButton)
    }
    

  • 发现代码非常的相似,可以抽取

    /**
    快速创建带高亮图片的BarButton
    parameter imageName:            正常时的图片名称
    parameter highlightedImageName: 高亮时的图片名称
    returns: UIBarButtonItem
    */
    private func createBarButtonItem(imageName: String, highlightedImageName: String) -> UIBarButtonItem {
      let button = UIButton()
      button.setBackgroundImage(UIImage(named: imageName), for: UIControlState.normal)
      button.setBackgroundImage(UIImage(named: highlightedImageName), for: UIControlState.highlighted)
      button.sizeToFit()
      return UIBarButtonItem(customView: button)
    }
    

  • 调用方式修改为:

    // 设置导航栏左右按钮
    navigationItem.leftBarButtonItem = createBarButtonItem(imageName: "navigationbar_friendsearch", highlightedImageName: "navigationbar_friendsearch_highlighted")
    
    // 设置导航栏右按钮
    navigationItem.rightBarButtonItem = createBarButtonItem(imageName: "navigationbar_pop", highlightedImageName: "navigationbar_pop_highlighted")
    

  • 发现这样代码还是有缺陷,如果在其他控制器需要创建带高亮图片的UIBarButtonItem,需要将这段代码复制过去,说明这段代码放在这里并不是最合适的地方,在OC里面我们通常会放在Category里面,在swift中的extension

    • 新建 UIBarButtonItem+Extension.swift 文件
    • 添加 createBarButtonItem 方法

      extension UIBarButtonItem {
        /**
         快速创建带高亮图片的BarButton
         parameter imageName:            正常时的图片名称
         parameter highlightedImageName: 高亮时的图片名称
         returns: UIBarButtonItem
         */
        class func createBarButtonItem(imageName: String, highlightedImageName: String) -> UIBarButtonItem {
            let button = UIButton()
            button.setBackgroundImage(UIImage(named: imageName), for: UIControlState.normal)
            button.setBackgroundImage(UIImage(named: highlightedImageName), for: UIControlState.highlighted)
            button.sizeToFit()
            return UIBarButtonItem(customView: button)
        }
      }
      

    • 调用方式修改为:

      // 设置导航栏左右按钮
      navigationItem.leftBarButtonItem = UIBarButtonItem.createBarButtonItem(imageName: "navigationbar_friendsearch", highlightedImageName: "navigationbar_friendsearch_highlighted")
      
      // 设置导航栏右按钮
      navigationItem.rightBarButtonItem = UIBarButtonItem.createBarButtonItem(imageName: "navigationbar_pop", highlightedImageName: "navigationbar_pop_highlighted")
      

    • 还不是特别方便,改成使用便利构造函数:

      extension UIBarButtonItem {
        /*
         快速创建带高亮图片的BarButton
         parameter imageName:            正常时的图片名称
         parameter highlightedImageName: 高亮时的图片名称
         returns: UIBarButtonItem
         */
        convenience init(imageName: String, highlightedImageName: String) {
            let button = UIButton()
      
            button.setBackgroundImage(UIImage(named: imageName), for: UIControlState.normal)
            button.setBackgroundImage(UIImage(named: highlightedImageName), for: UIControlState.highlighted)
            button.sizeToFit()
      
            self.init(customView: button)
        }
      }
      

    • 调用

      // 设置导航栏左右按钮
      navigationItem.leftBarButtonItem = UIBarButtonItem(imageName: "navigationbar_friendsearch", highlightedImageName: "navigationbar_friendsearch_highlighted")
      
      // 设置导航栏右按钮
      navigationItem.rightBarButtonItem = UIBarButtonItem(imageName: "navigationbar_pop", highlightedImageName: "navigationbar_pop_highlighted")