我可以获取某个 ID 中每个 <p> 和 </p> 之间的所有文本吗

Question

我使用了下面的代码，但它只能让我得到一个之间的文本，当它应该让我得到 5 <p> 和 </p> 之间的文本时

>             var myHTMLString = try String(contentsOf: myURL, encoding: .ascii)
            while let idRange = myHTMLString.range(of: "post-51"){
                myHTMLString=myHTMLString.substring(from: idRange.upperBound)
                if let paraRange = myHTMLString.range(of: "<p>"){
                    myHTMLString=myHTMLString.substring(from: paraRange.upperBound)
                    if let paraCloseRange = myHTMLString.range(of: "</p>"){
                        HTMLData = myHTMLString.substring(to: paraCloseRange.lowerBound)
                        textViewer.text = HTMLData
                        myHTMLString = myHTMLString.substring(from: paraCloseRange.upperBound)

                    }else{
                        //Handle paragraph close tag not found
                        print("Handle paragraph close tag not found")
                    }
                }else{
                    //Handle paragraph start tag not found
                    print("Handle paragraph start tag not found")
                }
            }

完整的 HTML 字符串是：`

<!-- main content -->
<div id="content" class="main-content-inner col-sm-12 col-md-9">
        <header>
        <h1 class="page-title">Community</h1>
    </header>
<article id="post-51" class="post-51 page type-page status-publish hentry">
    <!-- .entry-header -->
    <div class="entry-content">
        <h1>Your Experience, Your Programs</h1>
<p>The Purdue Honors College is dedicated to providing meaningful opportunities to enhance the honors student experience. We are building an interdisciplinary community of scholars by adding value through specialized programming and events that are connected to our pillars. The Honors College strives to create an environment in which every student can feel connected, learn, and grow as they each pursue greatness. To reach your full potential in the Honors College, students should attend at least three honors programs per semester outside of the regular curriculum requirements. We invite you to be a part of one of our many upcoming events as we ignite the imagination of our community and forge the future of our college.</p>
<hr />
<h3>Events Calendar</h3>
<p>The Honors College hosts events to keep students engaged with their peers and the Honors College faculty.</p>
<p><a href="https://honors.purdue.edu/community/calendar/">Click here to learn more about upcoming events in the Honors College.</a></p>
<hr />
<h3>Honors College and Residences</h3>
<p>The new 324,000-square-foot Honors College and Residences is the first of its kind in the state of Indiana. It encourages scholarship and connects students with faculty while being emblematic of the Mission of the Purdue Honors College: from the locally sourced building materials to LEED certification and interactive learning spaces.</p>
<p><a href="https://honors.purdue.edu/community/honors-college-and-residences/">Click here to learn more about the new Honors College and Residences buildings.</a></p>
<hr />
<h3>Honors Network News</h3>
<p><a href="https://honors.purdue.edu/community/honors-network-news/">Click here to view the Honors Network News archive.</a></p>
<hr />
<h3>News</h3>
<p>Stay up to date with news about the Honors College. Learn about the awesome things our students are doing and follow the Honors College on social media.</p>
<p><a href="https://honors.purdue.edu/community/news/">Click here to view more news about the Honors College.</a></p>
<hr />
<h3>Photo Gallery</h3>
<p><a href="https://honors.purdue.edu/community/photo-gallery/">Click here to view photos of Honors College events.</a></p>
<hr />
<h3>Published Works</h3>
<p><a href="https://honors.purdue.edu/community/published-works/">Click here to view the published works of the Honors College.</a></p>
<hr />
<h3>Signature Programs</h3>
<p><a href="https://honors.purdue.edu/community/signature-programs/">Click here to learn more about Signature Programs from the Honors College.</a></p>
<hr />
            </div><!-- .entry-content -->
    </article><!-- #post-## -->
`

Answer 1

把你的代码改成这个循环遍历所有

找到 id 后。看看我的评论，在满足特定条件后打破 while 循环非常重要。

 var myHTMLString = try String(contentsOf: myURL, encoding: .ascii)
if let idRange = myHTMLString.range(of: "post-51"){
        myHTMLString=myHTMLString.substring(from: idRange.upperBound)
        while let paraRange = myHTMLString.range(of: "<p>"){
            myHTMLString=myHTMLString.substring(from: paraRange.upperBound)
            if let paraCloseRange = myHTMLString.range(of: "</p>"){
                HTMLData = myHTMLString.substring(to: paraCloseRange.lowerBound)
                textViewer.text = HTMLData
                //AFTER YOU GET THE NEEDED INFORMATION, DO A break HERE to get out of while loop or you will loop through all <p>
                myHTMLString = myHTMLString.substring(from: paraCloseRange.upperBound)

            }else{
                //Handle paragraph close tag not found
                print("Handle paragraph close tag not found")
            }
        }
    }else{
        print("Handle id not found")
    }

Answer 2

我认为使用 off-screen Web 视图来临时加载 HTML 并检索您所追求的内容并不是不可能的。以下是如何做到这一点的示例：

class ViewController: UIViewController {

    // Declared as a property of the class to ensure it is not freed
    // from memory (because we're not adding it to the view hierarchy).
    let webView = UIWebView()

    override func viewDidLoad() {
        super.viewDidLoad()

        webView.delegate = self
        webView.loadHTMLString("<html><head></head><body><div id=\"hello\"><p>First</p><p>Second</p><p>Third</p></div></body></html>", baseURL: nil)
    }
}

extension ViewController: UIWebViewDelegate {
    func webViewDidFinishLoad(_ webView: UIWebView) {

        let result = webView.stringByEvaluatingJavaScript(from: "Array.prototype.slice.call(document.getElementById('hello').getElementsByTagName('p')).map(function(p) { return p.innerHTML }).join('|')")
        print(result)
    }
}

请注意stringByEvaluatingJavaScript 无法处理数组响应，因此我们将p 标记的内容与管道| 字符连接起来以将其返回给Swift。然后，您可以拆分管道上的字符串以获取数组。您可以将分隔符更改为您确定不会自然出现在 p 标记中的任何内容。

另外，Array.prototype.slice.call只是将getElementsByTagName返回的HTMLCollection转换成一个数组。