导航栏搜索框简单封装

//
//  NavigationSearchItemHelper.swift
//  NVRCloudIOS
//
//  Created by Nvr on 2018/11/16.
//  Copyright © 2018 zhangyu. All rights reserved.
//


typealias StringCallBack = (String) -> Void

import UIKit

@objc protocol NavSearchBtnClickProtocol {
    @objc func searchNavClick()
}

class NavigationSearchItemHelper: NSObject {

    var searchBar: UISearchBar?
    var searchItem: UIBarButtonItem!
    //需要添加searchItem到导航栏的控制器
    var vc: UIViewController?
    var searchStringCallBack: StringCallBack!
    var delegate: NavSearchBtnClickProtocol?
    var placeHolder: String = ""
    var title = ""
    var searchBarX:CGFloat = 65
    var hasBackBarItem = true

    func addSearchItem(serachDelegate: UIViewController,vcTitle:String, searchPlaceholder: String,hasBackItem:Bool = true, callBack:@escaping StringCallBack) {
        searchStringCallBack = callBack
        placeHolder = searchPlaceholder
        vc = serachDelegate
        title = vcTitle
        delegate = vc as? NavSearchBtnClickProtocol
        hasBackBarItem = hasBackItem
        addSerchItem()
        addSearchBar()
    }

    func addSerchItem() {
        searchItem = UIBarButtonItem.init(image: #imageLiteral(resourceName: "nav_btn_search_sel"), style: .plain, target: vc, action: #selector(delegate?.searchNavClick))
        vc?.navigationItem.rightBarButtonItem = searchItem
    }

    func addSearchBar() {

        if hasBackBarItem {
            searchBarX = 65
        }else{
            searchBarX = 10
        }


        searchBar = UISearchBar.init(frame: CGRect(x: searchBarX, y: 5, width: screen_width - 20, height: (vc?.navigationController?.navigationBar.frame.height)! - 10))
        searchBar?.barTintColor = UIColor.clear
        if let textfiled = searchBar?.subviews.first?.subviews.last as? UITextField {
            textfiled.tintColor = UIColor.textFeildTint
            textfiled.font = UIFont.systemFont(ofSize: 14)
        }

        searchBar?.tintColor = UIColor.white
        searchBar?.delegate = self
        searchBar?.placeholder = placeHolder
        searchBar?.isHidden = true
        if let bar = searchBar{
            vc?.navigationController?.navigationBar.addSubview(bar)
        }
    }
}

// MARK: UISearchBarDelegate
extension NavigationSearchItemHelper: UISearchBarDelegate {

    func searchBarShouldBeginEditing(_ searchBar: UISearchBar) -> Bool {
        searchBar.showsCancelButton = true

        return true
    }

    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        vc?.title = title
        searchBar.showsCancelButton = false
        searchBar.isHidden = true
        vc?.navigationItem.rightBarButtonItem = searchItem
        searchBar.resignFirstResponder()
        //取消点击后重新加载数据
        searchStringCallBack("")
    }

    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        searchStringCallBack(searchBar.text ?? "")
        searchBar.resignFirstResponder()

    }

}