Xamarin iOS WKWebView DidFinishNavigation和DidStartProvisionalNavigation未被调用

Question

我正在iOS Xamarin中实现WKWebView，我想在加载启动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，但是没有调用它们。我错过了什么

班级定义

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

导航代表功能

    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

补充杰森的答案。

您缺少可选委托方法所需的ExportAttribute，每当您IFooInterface成为ObjC委托时，Xamarin Studio自动完成引擎都会为您生成此Foo键入override（它应列出可选成员而非可选成员）。只有可选成员（c＃接口中的非抽象成员）才需要ExportAttribute。

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选择器作为参数。

您需要在使用语句中添加using Foundation，其中包含ExportAttribute。

[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");
}

希望这有帮助。

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();