Xamarin iOS WKWebView DidFinishNavigation 和 DidStartProvisionalNavigation 没有被调用

Question

我正在 iOS Xamarin 中实现 WKWebView，我想在加载开始和加载完成时做一些事情。我已经实现了 IWKNavigationDelegate 并添加了以下函数，但没有一个被调用。我错过了什么

类定义

 public partial class MasterViewController : UIViewController,IScanSuccessCallback, IWKScriptMessageHandler, IWKNavigationDelegate
{ }

导航委托功能

    public void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
    {
        Console.WriteLine ("DidFinishNavigation");
    }

    public void DidFailNavigation( WKWebView webView, WKNavigation navigation, NSError error )
    {
        // If navigation fails, this gets called
        Console.WriteLine("DidFailNavigation");
    }
    public void DidFailProvisionalNavigation( WKWebView webView, WKNavigation navigation, NSError error )
    {
        // If navigation fails, this gets called
        Console.WriteLine("DidFailProvisionalNavigation");
    }
    public void DidStartProvisionalNavigation( WKWebView webView, WKNavigation navigation )
    {
        // When navigation starts, this gets called
        Console.WriteLine("DidStartProvisionalNavigation");
    }

Answer 1

补充杰森的回答。

您缺少可选委托方法所需的ExportAttribute，当Foo 是ObjC 委托并且您键入override（它应该列出可选的而不是可选的成员）。 ExportAttribute 只有可选成员（c#接口中的非抽象成员）才需要。

在这种特殊情况下，WKNavigationDelegate ObjC 协议的所有成员都是可选的，因此您需要 Export 属性和 ObjC 选择器作为其参数。

你需要将using Foundation添加到你的using语句中，ExportAttribute在里面。

[Export ("webView:didFinishNavigation:")]
public void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
{
    Console.WriteLine ("DidFinishNavigation");
}

[Export ("webView:didFailNavigation:withError:")
public void DidFailNavigation( WKWebView webView, WKNavigation navigation, NSError error )
{
    // If navigation fails, this gets called
    Console.WriteLine("DidFailNavigation");
}

[Export ("webView:didFailProvisionalNavigation:withError:")]
public void DidFailProvisionalNavigation( WKWebView webView, WKNavigation navigation, NSError error )
{
    // If navigation fails, this gets called
    Console.WriteLine("DidFailProvisionalNavigation");
}

[Export ("webView:didStartProvisionalNavigation:")]
public void DidStartProvisionalNavigation( WKWebView webView, WKNavigation navigation )
{
    // When navigation starts, this gets called
    Console.WriteLine("DidStartProvisionalNavigation");
}

希望这会有所帮助。

Answer 2

您需要将 NavigationDelegate 类显式分配给 webview

WKWebView web = new WKWebView();

// if the current class implements IWKNavigationDelegate, you can do this
web.NavigationDelegate = this;

// or you can create a separate class that implements IWKNavigationDelegate
web.NavigationDelegate = new MyWebDelegate();