1.懶加載

private lazy var label : UILabel = {
       
        let label = UILabel()
        label.textColor = UIColor.blackColor()
        label.textAlignment = NSTextAlignment.Center
        label.font = UIFont.systemFontOfSize(18)
        
        return label
    }()

2.重寫model的set方法賦值（可選類型要先判斷為不為nil，為nil強轉會崩）

var model : WBModel? {
        
        didSet {
            label.text = model!.title
            
            //如果拼接的話要轉
            if let string = model?.title {
                label.text = "cell  \(string)"
            }
        }
        
    }

3.按鈕的點擊 ：

無參數Selector("btnWithLogin”) 或者 #selector(LoginViewController.btnWithLogin)

有參數Selector(“btnWithLogin:”)
#selector(MyDetailHeardView.btnWithLogin(_:))

btn_sure.addTarget(self, action: Selector(“btnWithLogin:"), forControlEvents: UIControlEvents.TouchUpInside)

注意：@objc別忘了這個！！！！！！
@objc private func btnWithLogin(btn : UIButton) -> Void {
        
        if delegate != nil {
            delegate?.myDetailHeardViewDidClick(btn.tag)
        }
    }

4.代理delegate

1.定義
protocol LoginInputViewDelegate : NSObjectProtocol {
    
    func didClickWithForget()
}

class LoginInputView: UIView {
    
    
    weak var delegate : LoginInputViewDelegate?
    
    //MARK: - 點擊了忘記密碼，別忘了@objc
    @objc private func btnWithForget() -> Void {
        
        if delegate != nil {
            delegate?.didClickWithForget()
        }
    }

    private lazy var btn_forget : UIButton = {
       
        let btn_forget = UIButton(type: UIButtonType.Custom)
        btn_forget.addTarget(self, action: #selector(LoginInputView.btnWithForget), forControlEvents: UIControlEvents.TouchUpInside)
        
        return btn_forget
    }()
}

2.實現
extension LoginViewController : LoginInputViewDelegate {
    
    func didClickWithForget() {
        print("點擊了忘記密碼")
    }
    
}

5.重寫frame的set方法,注意：如果頭部要出現空隙，y+的同時，height要-

    //重寫frame
    override var frame:CGRect{
        didSet {
            
            var newFrame = frame
            newFrame.origin.x += 10/2
            newFrame.size.width -= 10
            newFrame.origin.y += 10
            newFrame.size.height -= 10
            super.frame = newFrame
            
            
        }
    }

6. 移除通知

deinit
    {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

7.下載圖片dispatch_group_create用法

private func cachesImages(viewModels: [StatusViewModel])
    {
        // 0.創建一個組
        let group = dispatch_group_create()
        
        for viewModel in viewModels
        {
            // 1.從模型中取出配圖數組
            guard let picurls = viewModel.thumbnail_pic else
            {
                 // 如果當前微博沒有配圖就跳過, 繼續下載下一個模型的
                continue
            }
            // 2.遍歷配圖數組下載圖片
            for url in picurls
            {
                // 將當前的下載操作添加到組中
                dispatch_group_enter(group)
                
                // 3.3利用SDWebImage下載圖片
                
                SDWebImageManager.sharedManager().downloadImageWithURL(url, options: SDWebImageOptions(rawValue: 0), progress: nil, completed: { (image, error, _, _, _) -> Void in
                    NJLog("圖片下載完成")
                    // 將當前下載操作從組中移除
                    dispatch_group_leave(group)
                })
            }
        }
        
        // 監聽下載操作
        dispatch_group_notify(group, dispatch_get_main_queue()) { () -> Void in
            NJLog("全部下載完成")
            self.statuses = viewModels
        }
    }