ios - 对象符合 Swift 协议(protocol)

Question

任何人都可以帮助找到如何在 Swift 中编写这个

NSMutableDictionary<FBOpenGraphObject> *object = [FBGraphObject openGraphObjectForPost];

上面的 ObjectiveC 代码说 objectNSMutableDictionary 符合协议(protocol) FBOpenGraphObject。我试图像

这样 swift 地表示这一点

var object:FBOpenGraphObject, Dictionary = FBGraphObject.openGraphActionForPost()

// specify that this Open Graph object will be posted to Facebook
object.provisionedForPost = true   //This will not work

但这不合适，我无法为对象分配任何值。帮我弄清楚如何在 swift 中表示一个符合协议(protocol)的对象

Answer 1

也许你可以这样做:

var obj = FBGraphObject.openGraphActionForPost()
if let fbObj = obj as? FBOpenGraphObject {
    // specify that this Open Graph object will be posted to Facebook
    fbObj.provisionedForPost = true // use fbObj for FBOpenGraphObject-specific members
    obj["title"] = "Test hot spot" // use obj for Dictionary-specific members
    // Both obj and fbObj vars point to the same object
}