Swift系列之——UISearchBar的简单使用

本篇博客的语法适用于Swift3.0以上。

UISearchBar是一个苹果自带的搜索条，由一个文本框和几个按钮组成，当用户在文本框内输入部分内容之后，程序即可按照指定的规则执行搜索。

下面是UISearchBar的长相：

//
//  ViewController.swift
//  UISearchBarTest
//
//  Created by Mac on 2017/8/4.
//  Copyright © 2017年 Jing. All rights reserved.
//

import UIKit

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate {

    var tableArray: NSArray = ["UI",
                               "UIView",
                               "View",
                               "ViewController",
                               "Controller",
                               "UIViewController",
                               "Search",
                               "UISearchBar",
                               "Swift"]

    var searchArray: NSArray = []
    var isSearch = false//默认在非搜索状态下

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.tableView.tableHeaderView = self.searchBar;
        self.view.addSubview(tableView);
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    //使用懒加载方式来创建UITableView
    lazy var tableView: UITableView = {
        let tempTableView = UITableView (frame: self.view.bounds, style: UITableViewStyle.plain)
        tempTableView.delegate = self
        tempTableView.dataSource = self
        tempTableView.tableFooterView = UIView.init()

        return tempTableView
    }()

    //使用懒加载方式来创建UISearchBar
    lazy var searchBar: UISearchBar = {
        let tempSearchBar = UISearchBar(frame:CGRect(x: 0, y: 64, width: self.view.bounds.size.width, height: 40))
//        tempSearchBar.prompt = "查找图书";
        tempSearchBar.placeholder = "请输入搜索关键字";
        tempSearchBar.showsCancelButton = true;
        tempSearchBar.delegate = self

        return tempSearchBar
    }()

    //根据输入的关键字来过滤搜索结果
    func filterBySubstring(filterStr: NSString!) {
        isSearch = true
        let predicate = NSPredicate(format: "SELF CONTAINS[c] %@", filterStr)
        searchArray = tableArray.filtered(using: predicate) as NSArray
        tableView.reloadData()
    }

    //MARK: UITableViewDelegate
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if isSearch {
            return searchArray.count
        }
        else{
            return tableArray.count
        }
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let identifier = "cellId"
        var cell = tableView.dequeueReusableCell(withIdentifier: identifier)

        if cell == nil {
            cell = UITableViewCell.init(style: UITableViewCellStyle.default, reuseIdentifier: identifier)
        }

        let row = indexPath.row
        if isSearch {
            cell?.textLabel?.text = searchArray[row] as? String
        }
        else{
            cell?.textLabel?.text = tableArray[row] as? String
        }

        return cell!
    }

    //MARK: UISearchBarDelegate
    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        isSearch = false
        searchBar.resignFirstResponder()
        tableView.reloadData()
    }

    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        filterBySubstring(filterStr: searchBar.text! as NSString)
    }

    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        filterBySubstring(filterStr: searchText as NSString)
    }

}