How to add margin at top of WKWebView in IOS Swift

Question

I am showing a pdf file in WKWebView in IOS swift, and it showing fine. I am loading pdf file from server. But some part of file is being hidden behind top navigation bar. I want to add margin at top of WKWebView. Here is my current code.

    let myBlog = file
    let url = NSURL(string: myBlog)
    let request = NSURLRequest(url: url! as URL)

    // init and load request in webview.
    webView = WKWebView(frame: self.view.frame)
    webView.navigationDelegate = self
    webView.load(request as URLRequest)

    self.view.addSubview(webView)

    // webView.translatesAutoresizingMaskIntoConstraints = false
    // webView.addConstraints([NSLayoutConstraint(item: webView, attribute: .height, relatedBy: .equal, toItem: view, attribute: .height, multiplier: 1, constant: 0)])

    self.view.addSubview(sv)       
    let pdfVC = UIViewController()
    pdfVC.view.addSubview(webView)
    pdfVC.title = "File"
    self.navigationController?.pushViewController(pdfVC, animated: true)

Here the commented code is how I am trying to add margin and not working.

Answer 1

webView = WKWebView(frame: self.view.frame)

在上面的行中，设置框架，使其离开顶部边缘，并从高度减小给定边缘。

Answer 2

尝试设置layoutMargin，它应该可以解决问题。

self.webView.layoutMargins = UIEdgeInsets(top: 8, left: 8, bottom: 8, right: 8)

Answer 3

First of all set translatesAutoresizingMaskIntoConstraints of webView to false , ie

    webView.translatesAutoresizingMaskIntoConstraints = false

Now, add proper constraints of webView to view's safeAreaLayoutGuide or layoutMarginsGuide , ie

    var guide: UILayoutGuide
    if #available(iOS 11.0, *) {
        guide = self.view.safeAreaLayoutGuide
    } else {
        guide = self.view.layoutMarginsGuide
    }

    NSLayoutConstraint.activate([
        webView.leadingAnchor.constraint(equalTo: guide.leadingAnchor),
        webView.trailingAnchor.constraint(equalTo: guide.trailingAnchor),
        webView.topAnchor.constraint(equalTo: guide.bottomAnchor),
        webView.bottomAnchor.constraint(equalTo: guide.bottomAnchor)
        ])

Answer 4

您可以使用以下行添加上边距

webView = WKWebView(frame: CGRect(x: 0, y: 40, width: self.view.bounds.width, height: self.view.bounds.height - 40)