Swift - UIWebView和UIToolBar使用

功能介绍：

使用UIWebView和UIToolBar创建一个简单的浏览器，熟悉这两个控件的使用

• 输入网址，点击“搜索”或者点击键盘return键进行搜索
• 加载过程有加载进度条显示
• 有后退、前进和重新加载功能

代码：

import UIKit

class ViewController: UIViewController, UITextFieldDelegate, UIWebViewDelegate {

    var toolBar : UIToolbar!
    var progressView : UIProgressView!
    var textField : UITextField!
    var searchButton : UIButton!
    var webView : UIWebView!
    var loadIndicator : UIActivityIndicatorView!
    
    var timer : Timer!
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        //创建工具条
        setupToolBar()
        
        //创建进度条
        progressView = UIProgressView(progressViewStyle: .bar)
        progressView.frame = CGRect(x: 0, y: self.toolBar.frame.maxY, width: self.view.bounds.width, height: 10)
        progressView.progressViewStyle = .bar
        //设置初始值
        progressView.progress = 0
        view.addSubview(progressView)
        
        //创建定时器
        timer = Timer(timeInterval: 0.2, target: self, selector: #selector(loadProgress), userInfo: nil, repeats: true)
        timer.invalidate()
        
        //创建go按钮
        searchButton = UIButton(frame: CGRect(x: view.bounds.width - 20 - 40, y: progressView.frame.maxY + 5, width: 40, height: 40))
        searchButton.setTitle("搜索", for: .normal)
        searchButton.setTitleColor(UIColor.blue, for: .normal)
        searchButton.addTarget(self, action: #selector(goButtonAction), for: .touchUpInside)
        view.addSubview(searchButton)
        
        //创建输入框
        textField = UITextField(frame: CGRect(x: 10, y: progressView.frame.maxY + 5, width: view.bounds.width - 10 * 2 - 40 - 10, height: 40))
        textField.layer.borderWidth = 1.0
        textField.layer.borderColor = UIColor.black.cgColor
        textField.placeholder = "输入网址"
        textField.delegate = self
        view.addSubview(textField)
        
        //创建webView
        webView = UIWebView(frame: CGRect(x: 0, y: textField.frame.maxY + 10, width: self.view.bounds.width, height: self.view.bounds.height - textField.frame.maxY - 10))
        webView.delegate = self
        view.addSubview(webView)
        
        //创建加载圈
        loadIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
        loadIndicator.center = view.center
        view.addSubview(loadIndicator)
        
    }
    
    func setupToolBar() {
        //创建一个工具条
        self.toolBar = UIToolbar(frame: CGRect(x: 0, y: 20, width: self.view.bounds.width, height: 44))
        self.view.addSubview(self.toolBar)
        
        //后退按钮
        let backButton = UIBarButtonItem(image:UIImage.init(named: "back") , style: .plain, target: self, action: #selector(backAction))
        
        //第一个占位
        let space1 = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        
        //重新加载按钮
        let reloadButton = UIBarButtonItem(image: UIImage.init(named: "reload"), style: .plain, target: self, action: #selector(reloadAction))
        
        //第二个占位
        let space2 = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        
        //停止按钮
        let stopButton = UIBarButtonItem(image: UIImage.init(named: "stop"), style: .plain, target: self, action: #selector(stopAction))
        
        //第三个占位
        let space3 = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        
        //前进按钮
        let forwardButton = UIBarButtonItem(image: UIImage.init(named: "forward"), style: .plain, target: self, action: #selector(forwardAction))
        
        
        
        self.toolBar.items = [backButton, space1, reloadButton, space2, stopButton, space3, forwardButton]
        
        
    }
    
    // MARK: - events
    //加载URL
    func loadUrl(urlString:String) {
        if urlString.isEmpty {
            return
        }
        let url = URL(string: urlString)
        let urlRequest = URLRequest(url: url!)
        webView.loadRequest(urlRequest)
    }
    
    //后退
    @objc func backAction() {
       webView.goBack()
    }
    
    //重新加载
    @objc func reloadAction() {
        webView.reload()
    }
    
    //停止
    @objc func stopAction() {
        webView.stopLoading()
    }
    
    //前进
    @objc func forwardAction() {
        webView.goForward()
    }
    
    //加载进度计算
    @objc func loadProgress() {
        //如果进度条已满
        if progressView.progress >= 1.0 {
            //停用定时器
            timer.invalidate()
        } else {
            progressView.setProgress(progressView.progress + 0.02, animated: true)
        }
    }

    @objc func goButtonAction() {
        //收起键盘
        textField.resignFirstResponder()
        if (textField.text?.isEmpty)! {
            let alert = UIAlertController(title: "警告", message: "请输入网址", preferredStyle: .alert)
            let alertAction = UIAlertAction(title: "好的", style: .default, handler: nil)
            alert.addAction(alertAction)
            self.present(alert, animated: true, completion: nil)
            return
        }
        
        loadUrl(urlString: textField.text!)
    }
    
    //MARK: - UITextField Delegate
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        loadUrl(urlString: textField.text!)
        return true
    }
    
    //MARK: - UIWebView Delegate
    func webViewDidStartLoad(_ webView: UIWebView) {
        progressView.setProgress(0, animated: false)
        timer.fire()
        loadIndicator.startAnimating()
    }
    
    func webViewDidFinishLoad(_ webView: UIWebView) {
        loadIndicator.stopAnimating()
        progressView.setProgress(1, animated: false)
        timer.invalidate()
    }
    
    func webView(_ webView: UIWebView, didFailLoadWithError error: Error) {
        let alertController = UIAlertController(title: "出错!",
                                                message: error.localizedDescription,
                                                preferredStyle: .alert)
        let okAction = UIAlertAction(title: "确定", style: .cancel, handler: nil)
        alertController.addAction(okAction)
        self.present(alertController, animated: true, completion: nil)
    }
}

实现效果：

注意：

在iOS 9的时候,默认非HTTS的网络是被禁止的,我们可以在info.plist文件中添加NSAppTransportSecurity字典,将NSAllowsArbitraryLoads设置为YES来禁用ATS;