swift - NSURLProtocol SWIFT 错误

Question

我正在尝试在我的应用程序中实现一个 NSURLProtocol，它将获取以 myApp://... 开头的 URL

我在新的 SWIFT 文件中创建了协议(protocol)并在 AppDelegate 中实现:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
    NSURLProtocol.registerClass(myURLProtocol)
    return true
} 

但我不断收到此错误。我不知道如何将 canInitWithRequest 定义到我的 webViews..

2014-08-03 21:10:27.632 SubViewTest[6628:156910] * WebKit discarded an uncaught exception in the webView:decidePolicyForNavigationAction:request:frame:decisionListener: delegate: * -canInitWithRequest: only defined for abstract class. Define -[_TtC11SubViewTest13myURLProtocol canInitWithRequest:]!

Answer 1

正如您所得到的异常中所述，myURLProtocol 类应该实现 canInitWithRequest 类函数/方法；准确地说，它应该重写基类的抽象方法。

以下是头文件中 NSURLProtocol 的 canInitWithRequest 方法的注释描述:

/*!
@method canInitWithRequest:
@abstract This method determines whether this protocol can handle
the given request.
@discussion A concrete subclass should inspect the given request and
determine whether or not the implementation can perform a load with
that request. This is an abstract method. Sublasses must provide an
implementation. The implementation in this class calls
NSRequestConcreteImplementation.
@param request A request to inspect.
@result YES if the protocol can handle the given request, NO if not.
*/

所以，答案是:将以下代码添加到您的 myURLProtocol 类中:

class func canInitWithRequest(request: NSURLRequest!) -> Bool {
    return true;
}

备注:您可能需要在返回 true 或 false 之前检查请求对象，只是不要忘记添加此代码:)