ios - 为什么我的模拟以编程方式获得与 anchor /约束有关的空白黑屏？
<p><p>这是我的代码。我试图将 webViewanchor 的顶部限制在 ViewController 顶部布局指南的底部，但我只是得到一个黑屏，有时控制台中出现 <strong>错误:</strong> </p>
<pre><code> Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want.
Try this:
(1) look at each constraint and try to figure out which you don't expect;
(2) find the code that added the unwanted constraint or constraints and fix it.
(Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<_UILayoutSupportConstraint:0x608000284d30 _UILayoutSpacer:0x6080001aa560'UIVC-topLayoutGuide'.height == 20 (active)>",
"<_UILayoutSupportConstraint:0x6080002850a0 V:|-(0)- (active, names: '|':UIView:0x7fcfcac26cd0 )>",
"<NSAutoresizingMaskLayoutConstraint:0x608000280fa0 h=--& v=--& WKWebView:0x7fcfcb09a400.midY == 0 (active)>",
"<NSAutoresizingMaskLayoutConstraint:0x608000280ff0 h=--& v=--& WKWebView:0x7fcfcb09a400.height == 0 (active)>",
"<NSLayoutConstraint:0x6080002846f0 V:-(3)- (active)>",
"<NSAutoresizingMaskLayoutConstraint:0x608000281220 h=--& v=--& 'UIView-Encapsulated-Layout-Top' UIView:0x7fcfcac26cd0.minY == 0 (active, names: '|':UIViewControllerWrapperView:0x7fcfcac08120 )>"
)
</code></pre>
<p><strong>代码 -</strong></p>
<pre><code>import UIKit
import WebKit
class webViewController: UIViewController, WKNavigationDelegate {
override func loadView() {
self.view = UIView()
let webView = WKWebView()
// webView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(webView)
let topConstraint = webView.topAnchor.constraint(equalTo: self.topLayoutGuide.bottomAnchor, constant: 3)
topConstraint.isActive = true
let url = NSURL(string: "https://www.google.com")
if let selectedURL = url {
let request = NSURLRequest(url: selectedURL as URL) as URLRequest
webView.load(request)
}
}
}
</code></pre></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>添加导航委托(delegate):</p>
<pre><code>webView.navigationDelegate = self
</code></pre>
<p>然后听错误和导航代表，你将能够看到真正发生或没有发生的事情。</p></p>
<p style="font-size: 20px;">关于ios - 为什么我的模拟以编程方式获得与 anchor /约束有关的空白黑屏？，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/41045099/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/41045099/
</a>
</p>
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