ios - 如何只显示部分网页内容(swift)

Question

我是编码新手(完全没有任何编程语言背景)。我正在努力学习快速。我想创建一个简单的天气应用程序，在用户进入城市后以文本形式显示天气信息。我正在从 weather-forecast.com 获取内容。我已经弄清楚如何加载网页内容，但我只想显示页面内容的一个片段(一段)，而不是整个页面。有人可以告诉我该怎么做吗？

{
import UIKit

class ViewController: UIViewController, UIWebViewDelegate {

    @IBOutlet weak var cityText: UITextField!

    @IBOutlet weak var webContent: UIWebView!

    @IBAction func GoButtonPressed(sender: AnyObject) {

        let url = NSURL (string: "http://www.weather-forecast.com");
        let requestObj = NSURLRequest(URL: url!); 
        webContent.loadRequest(requestObj);
    }

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

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

Answer 1

这是一个简单的 View Controller 示例，它只加载网站 dribble.com 的一部分。 Controller 具有选择 DOM 元素并仅显示该元素的方法。它非常简单，但功能强大，足以展示您可以如何在此方面进一步开展工作。

import UIKit
import JavaScriptCore
import WebKit

class TestViewController: UIViewController {

    private weak var webView: WKWebView!

    private var userContentController: WKUserContentController!

    override func viewDidLoad() {
        super.viewDidLoad()
        createViews()

        loadPage("https://dribbble.com/", partialContentQuerySelector: ".dribbbles.group")
    }

    private func createViews() {
         userContentController = WKUserContentController()

        let configuration = WKWebViewConfiguration()
        configuration.userContentController = userContentController

        let webView = WKWebView(frame: view.bounds, configuration: configuration)
        webView.setTranslatesAutoresizingMaskIntoConstraints(false)
        view.addSubview(webView)

        let views: [String: AnyObject] = ["webView": webView, "topLayoutGuide": topLayoutGuide]
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[topLayoutGuide][webView]|", options: .allZeros, metrics: nil, views: views))
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[topLayoutGuide][webView]|", options: .allZeros, metrics: nil, views: views))


        self.webView = webView
    }

    private func loadPage(urlString: String, partialContentQuerySelector selector: String) {
        userContentController.removeAllUserScripts()
        let userScript = WKUserScript(source: scriptWithDOMSelector(selector),
        injectionTime: WKUserScriptInjectionTime.AtDocumentEnd,
            forMainFrameOnly: true)

        userContentController.addUserScript(userScript)

        let url = NSURL(string: urlString)!
        webView.loadRequest(NSURLRequest(URL: url))
    }

    private func scriptWithDOMSelector(selector: String) -> String {
        let script =
        "var selectedElement = document.querySelector('\(selector)');" +
        "document.body.innerHTML = selectedElement.innerHTML;"
        return script
    }

}

上面示例中显示的 View Controller 仅加载 dribble 网站内的照片、设计部分。