ihealth_ios/Inhealth/UIViewController+NavigationBar.swift

//
//  UIViewController+NavigationBar.swift
//  Inhealth
//
//  Created by weclouds on 2019/12/10.
//  Copyright © 2019 weclouds. All rights reserved.
//

import UIKit

 class IHTitleView: UIView {
 
    var titleColor  : UIColor?{
         didSet{
             titleLabel?.textColor = titleColor
         }
     }
   var navBarTitle : String?{
        didSet{
            titleLabel?.text = self.navBarTitle
        }
    }
   fileprivate var titleLabel :UILabel?
   fileprivate override init(frame: CGRect) {
        super.init(frame: frame)
        self.frame =   CGRect(x: 0, y: 0, width: KSCREENWIDTH , height: KNavBarHeight)
        setTitleView()
    }
    fileprivate func setTitleView()  {
        titleLabel = UILabel()
        titleLabel!.textColor = UIColor(hexString: "#666666")
        titleLabel!.font = UIFont(name: Alibaba_PuHuiTi_Bold, size: 14)
        addSubview(titleLabel!)
        
        //这里要使用相对位置，否则位置会跑偏
        titleLabel!.snp.makeConstraints { (make) in
            make.top.bottom.left.right.equalToSuperview()
        }
    }
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    //重写这个方法，否则设置的titleView回回到中间
    internal override var intrinsicContentSize: CGSize{
        get{
            return UIView.layoutFittingExpandedSize
        }
    }
}
fileprivate struct AssociatedKeys {
    fileprivate static var navigationBarTitleKey :String = "IHNavigationBarTitleKey"
    fileprivate static var titleViewKey :String = "IHTitleViewKey"
}

extension UIViewController{
    //添加自定义标题属性
    public var navigationBarTitle :String?{
        get{
            return objc_getAssociatedObject(self, &AssociatedKeys.navigationBarTitleKey) as? String
        }
        set{
            objc_setAssociatedObject(self, &AssociatedKeys.navigationBarTitleKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
            setTitleView()
        }
        
      
    }

    fileprivate var titleView :IHTitleView?{
        get{
            return objc_getAssociatedObject(self, &AssociatedKeys.titleViewKey) as? IHTitleView
        }
        set{
            objc_setAssociatedObject(self, &AssociatedKeys.titleViewKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
    
   fileprivate func setTitleView()  {
        //导航栏的渲染方式
        if titleView == nil {
           titleView = IHTitleView()
        }

        self.navigationItem.titleView = titleView
        titleView?.sizeToFit()
         titleView?.navBarTitle = navigationBarTitle
    }
    
    

    

}