Swift - Type '*' does not conform to protocol '*'

I got this error message when trying to create a Message class.

尝试创建Message类时出现此错误消息。

'Message' does not conform to protocol 'JSQMessageData'

JSQMessageData got from https://github.com/jessesquires/JSQMessagesViewController

JSQMessageData来自https://github.com/jessesquires/JSQMessagesViewController

My code

import Foundation

class Message : NSObject, JSQMessageData {

    var senderId_ : String!
    var senderDisplayName_ : String!
    var date_ : NSDate
    var isMediaMessage_ : Bool
    var hash_ : Int = 0
    var text_ : String

    init(senderId: String, senderDisplayName: String?, isMediaMessage: Bool, hash: Int, text: String) {
        self.senderId_ = senderId
        self.senderDisplayName_ = senderDisplayName
        self.date_ = NSDate()
        self.isMediaMessage_ = isMediaMessage
        self.hash_ = hash
        self.text_ = text
    }

    func senderId() -> String! {
        return senderId_;
    }

    func senderDisplayName() -> String! {
        return senderDisplayName_;
    }

    func date() -> NSDate! {
        return date_;
    }

    func isMediaMessage() -> Bool! {
        return isMediaMessage_;
    }

    func hash() -> Int? {
        return hash_;
    }

    func text() -> String! {
        return text_;
    }
}

JSQMessageData.h

#import <Foundation/Foundation.h>
#import "JSQMessageMediaData.h"

@protocol JSQMessageData <NSObject>

@required

- (NSString *)senderId;
- (NSString *)senderDisplayName;
- (NSDate *)date;
- (BOOL)isMediaMessage;
- (NSUInteger)hash;

@optional

- (NSString *)text;
- (id<JSQMessageMediaData>)media;

@end

Please advice how to fix this protocol issue. Thank you.

请建议如何解决此协议问题。谢谢。

2 个解决方案

#1

There are two problems:

有两个问题:

1. hash is defined as a method that returns an NSUInteger in the protocol. Also, NSUInteger can't be nil in Objective-C, so you can't return an optional. You need to change its implementation in the Message class to return an UInt

   hash被定义为在协议中返回NSUInteger的方法。另外,NSUInteger在Objective-C中不能为零,因此您无法返回可选项。您需要在Message类中更改其实现以返回UInt

   func hash() -> UInt {
       return UInt(hash_);
   }
   

or simply return hash_ and change hash_ from Int to UInt itself.

或者简单地返回hash_并将hash从Int更改为UInt本身。

2. BOOL can't be nil in Objective-C, so to conform to the protocol you need to change isMediaMessage() to return a non optional Bool by removing the !:

   在Objective-C中BOOL不能为零,因此要符合您需要更改的协议isMediaMessage()以通过删除!来返回非可选的Bool:

   func isMediaMessage() -> Bool {
       return isMediaMessage_;
   }
   

#2

The problem could be "hash", that is an unsigned int in the protocol and just an int in the implementation.

问题可能是“哈希”,即协议中的unsigned int,只是实现中的int。