问题
I want to implement an imessage app, however being new to the messages framework and iMessage apps being such a new thing there aren't many resources. So I am following the WWDC video and using Apples providing sample app for a guide.
I have three views, the MessageViewController which handles pretty much all the functionality and then a CreateViewController and a DetailsViewController. 
I am simply trying to create an MSMessage from the CreateViewController and display in the DetailsViewController.. then add to the data.
However I get a crash when trying to create the data.
@IBAction func createAction(_ sender: AnyObject) {
    //present full screen for create list
    self.delegate?.createViewControllerDidSelectAdd(self as! CreateViewControllerDelegate)        
}
The data type I am trying to pass is the dictionary from a struct:
struct data {
var title: String!
var date: Date!
var dictionary = ["title" : String(), "Array1" : [String](), "Array2" : [String]() ] as [String : Any]
}
So here's how things are set up;
MessagesViewController
class MessagesViewController: MSMessagesAppViewController, {
// MARK: Responsible for create list button
func composeMessage(for data: dataItem) {
    let messageCaption = NSLocalizedString("Let's make", comment: "")
    let dictionary = data.dictionary
    func queryItems(dictionary: [String:String]) -> [URLQueryItem] {
        return dictionary.map {
            URLQueryItem(name: $0, value: $1)
        }
    }
    var components = URLComponents()
    components.queryItems = queryItems(dictionary: dictionary as! [String : String])
    let layout = MSMessageTemplateLayout()
    layout.image = UIImage(named: "messages-layout-1.png")!
    layout.caption = messageCaption
    let message = MSMessage()
    message.url = components.url!
    message.layout = layout
    message.accessibilityLabel = messageCaption
    guard let conversation = activeConversation else  { fatalError("Expected Convo") }
    conversation.insert(message) { error in
        if let error = error {
            print(error)
        }
    }
}
}
extension MessagesViewController: CreateViewControllerDelegate {
func createViewControllerDidSelectAdd(_ controller: CreateViewControllerDelegate) {
    //CreatesNewDataItem
    composeMessage(for: dataItem())
}
}
CreateViewController
/**
 A delegate protocol for the `CreateViewController` class.
*/
protocol CreateViewControllerDelegate : class {
func createViewControllerDidSelectAdd(_ controller: CreateViewControllerDelegate)
}
class CreateViewController: UIViewController {
static let storyboardIdentifier = "CreateViewController"
weak var delegate: CreateViewControllerDelegate?
@IBAction func create(_ sender: AnyObject) {
    //present full screen for create list
    self.delegate?.createViewControllerDidSelectAdd(self as! CreateListViewControllerDelegate)
}
}
Would someone show where I am going wrong and how I can send a MSMessage? If I am able to send the message I should then be able to receive and resend. 
回答1:
One issue I see, without being able to debug this myself: you are setting your components.queryItems to your dictionary var cast as [String:String], but the dictionary returned from data.dictionary is not a [String:String], but a [String:Any]
In particular, dictionary["Array1"] is an array of Strings, not a single string. Same for dictionary["Array2"]. URLQueryItem expects to be given two strings in its init(), but you're trying to put a string and an array of strings in (though I'm not sure that you're actually getting to that line in your queryItems(dictionary:) method.
Of course, your dataItem.dictionary is returning a dictionary with 4 empty values. I'm not sure that's what you want.
来源:https://stackoverflow.com/questions/39600081/how-to-send-msmessage-in-messages-extension