> ## Documentation Index
> Fetch the complete documentation index at: https://wukong.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# 高级功能

> WuKongIM iOS SDK 高级功能，包括自定义消息类型和扩展功能

高级功能为开发者提供了扩展 WuKongIM iOS SDK 的能力，包括自定义消息类型、附件消息处理等企业级功能。

## 自定义消息

### 自定义普通消息

我们以自定义一个 GIF 消息为例，展示如何创建自定义消息类型。

#### 第一步：继承 WKMessageContent 和定义消息结构

<CodeGroup>
  ```objc Objective-C theme={null}
  @interface WKGIFContent : WKMessageContent

  // GIF的地址
  @property(nonatomic, copy) NSString *url;
  // 宽度
  @property(nonatomic, assign) NSInteger width;
  // 高度
  @property(nonatomic, assign) NSInteger height;

  @end
  ```

  ```swift Swift theme={null}
  class WKGIFContent: WKMessageContent {
      
      // GIF的地址
      var url: String?
      // 宽度
      var width: Int = 0
      // 高度
      var height: Int = 0
  }
  ```
</CodeGroup>

#### 第二步：编码和解码

最终传递的消息内容为 `{"type":3,"url":"xxxx","width":xxx,"height":xxx}`

<CodeGroup>
  ```objc Objective-C theme={null}
  @implementation WKGIFContent

  // 定义消息正文类型
  - (NSNumber*)contentType {
      return @(3);
  }

  // 发送消息时对消息内容编码
  - (NSDictionary *)encodeWithJSON {
      NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
      [dataDict setObject:self.url ?: @"" forKey:@"url"];
      [dataDict setObject:@(self.width) forKey:@"width"];
      [dataDict setObject:@(self.height) forKey:@"height"];
      return dataDict;
  }

  // 收到消息时对消息内容解码
  - (void)decodeWithJSON:(NSDictionary *)contentDic {
      self.url = contentDic[@"url"];
      self.width = contentDic[@"width"] ? [contentDic[@"width"] integerValue] : 100;
      self.height = contentDic[@"height"] ? [contentDic[@"height"] integerValue] : 100;
  }

  // 最近会话显示的内容
  - (NSString *)conversationDigest {
      return @"[GIF表情]";
  }

  @end
  ```

  ```swift Swift theme={null}
  extension WKGIFContent {
      
      // 定义消息正文类型
      override func contentType() -> NSNumber {
          return NSNumber(value: 3)
      }
      
      // 发送消息时对消息内容编码
      override func encodeWithJSON() -> [String: Any] {
          var dataDict: [String: Any] = [:]
          dataDict["url"] = url ?? ""
          dataDict["width"] = width
          dataDict["height"] = height
          return dataDict
      }
      
      // 收到消息时对消息内容解码
      override func decodeWithJSON(_ contentDic: [String: Any]) {
          url = contentDic["url"] as? String
          width = (contentDic["width"] as? Int) ?? 100
          height = (contentDic["height"] as? Int) ?? 100
      }
      
      // 最近会话显示的内容
      override func conversationDigest() -> String {
          return "[GIF表情]"
      }
  }
  ```
</CodeGroup>

#### 第三步：注册

<CodeGroup>
  ```objc Objective-C theme={null}
  [[WKSDK shared] registerMessageContent:WKGIFContent.class];
  ```

  ```swift Swift theme={null}
  WKSDK.shared().registerMessageContent(WKGIFContent.self)
  ```
</CodeGroup>

### 完整 GIF 消息实现示例

```objc theme={null}
@interface WKGIFContent : WKMessageContent

@property(nonatomic, copy) NSString *url;
@property(nonatomic, assign) NSInteger width;
@property(nonatomic, assign) NSInteger height;
@property(nonatomic, copy) NSString *thumbnail; // 缩略图
@property(nonatomic, assign) NSTimeInterval duration; // 动画时长
@property(nonatomic, assign) NSInteger fileSize; // 文件大小

@end

@implementation WKGIFContent

- (NSNumber*)contentType {
    return @(3);
}

- (NSDictionary *)encodeWithJSON {
    NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
    [dataDict setObject:self.url ?: @"" forKey:@"url"];
    [dataDict setObject:@(self.width) forKey:@"width"];
    [dataDict setObject:@(self.height) forKey:@"height"];
    
    if (self.thumbnail) {
        [dataDict setObject:self.thumbnail forKey:@"thumbnail"];
    }
    if (self.duration > 0) {
        [dataDict setObject:@(self.duration) forKey:@"duration"];
    }
    if (self.fileSize > 0) {
        [dataDict setObject:@(self.fileSize) forKey:@"file_size"];
    }
    
    return dataDict;
}

- (void)decodeWithJSON:(NSDictionary *)contentDic {
    self.url = contentDic[@"url"];
    self.width = contentDic[@"width"] ? [contentDic[@"width"] integerValue] : 100;
    self.height = contentDic[@"height"] ? [contentDic[@"height"] integerValue] : 100;
    self.thumbnail = contentDic[@"thumbnail"];
    self.duration = contentDic[@"duration"] ? [contentDic[@"duration"] doubleValue] : 0;
    self.fileSize = contentDic[@"file_size"] ? [contentDic[@"file_size"] integerValue] : 0;
}

- (NSString *)conversationDigest {
    return @"[GIF动图]";
}

// 搜索关键词
- (NSString *)searchableWord {
    return @"[GIF] [动图] [表情]";
}

// 验证消息内容
- (BOOL)isValid {
    return self.url.length > 0 && self.width > 0 && self.height > 0;
}

@end

// 注册 GIF 消息类型
[[WKSDK shared] registerMessageContent:WKGIFContent.class];

// 发送 GIF 消息
- (void)sendGIFMessage:(WKChannel *)channel gifURL:(NSString *)gifURL width:(NSInteger)width height:(NSInteger)height {
    WKGIFContent *gifContent = [[WKGIFContent alloc] init];
    gifContent.url = gifURL;
    gifContent.width = width;
    gifContent.height = height;
    
    if ([gifContent isValid]) {
        [[WKSDK shared].chatManager sendMessage:gifContent channel:channel];
    }
}
```

### 自定义附件消息

自定义附件消息的流程与普通消息差异不大，我们以图片消息为例。

#### 第一步：继承 WKMediaMessageContent

<Note>
  注意这里是继承 WKMediaMessageContent 不是 WKMessageContent
</Note>

最终传递的消息内容为 `{"type":4,"url":"xxxx","width":xxx,"height":xxx}`

<CodeGroup>
  ```objc Objective-C theme={null}
  @interface WKImageContent : WKMediaMessageContent

  @property(nonatomic, assign) CGFloat width; // 图片宽度
  @property(nonatomic, assign) CGFloat height; // 图片高度
  @property(nonatomic, strong) NSData *imageData; // 图片数据

  @end
  ```

  ```swift Swift theme={null}
  class WKImageContent: WKMediaMessageContent {
      
      var width: CGFloat = 0 // 图片宽度
      var height: CGFloat = 0 // 图片高度
      var imageData: Data? // 图片数据
  }
  ```
</CodeGroup>

#### 第二步：编码解码和将需要上传的数据写入本地路径

<CodeGroup>
  ```objc Objective-C theme={null}
  @implementation WKImageContent

  // 定义消息正文类型
  - (NSNumber*)contentType {
      return @(4);
  }

  // 将图片数据写入到本地路径，这样后面的上传任务会将此路径的附件上传到服务器
  - (void)writeDataToLocalPath {
      [super writeDataToLocalPath];
      [self.imageData writeToFile:self.localPath atomically:YES];
  }

  // 附件消息当附件上传成功后会获取到上传后的self.remoteUrl下载地址，我们只需要将此下载地址编码到json里
  // 附件的上传任务进度管理请查看 [WKSDK shared].mediaManager
  - (NSDictionary *)encodeWithJSON {
      NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
      [dataDict setObject:self.remoteUrl ?: @"" forKey:@"url"];
      [dataDict setObject:@(self.width) forKey:@"width"];
      [dataDict setObject:@(self.height) forKey:@"height"];
      return dataDict;
  }

  // 当收到消息需要解码，这时候我们只需要将下载地址url赋值给self.remoteUrl后
  // 下载任务会通过self.remoteUrl的下载地址进行下载附件
  // 附件的下载任务进度管理请查看 [WKSDK shared].mediaManager
  - (void)decodeWithJSON:(NSDictionary *)contentDic {
      self.remoteUrl = contentDic[@"url"];
      self.width = contentDic[@"width"] ? [contentDic[@"width"] floatValue] : 0;
      self.height = contentDic[@"height"] ? [contentDic[@"height"] floatValue] : 0;
  }

  - (NSString *)conversationDigest {
      return @"[图片]";
  }

  @end
  ```

  ```swift Swift theme={null}
  extension WKImageContent {
      
      // 定义消息正文类型
      override func contentType() -> NSNumber {
          return NSNumber(value: 4)
      }
      
      // 将图片数据写入到本地路径
      override func writeDataToLocalPath() {
          super.writeDataToLocalPath()
          if let data = imageData, let path = localPath {
              try? data.write(to: URL(fileURLWithPath: path))
          }
      }
      
      // 编码消息内容
      override func encodeWithJSON() -> [String: Any] {
          var dataDict: [String: Any] = [:]
          dataDict["url"] = remoteUrl ?? ""
          dataDict["width"] = width
          dataDict["height"] = height
          return dataDict
      }
      
      // 解码消息内容
      override func decodeWithJSON(_ contentDic: [String: Any]) {
          remoteUrl = contentDic["url"] as? String
          width = (contentDic["width"] as? CGFloat) ?? 0
          height = (contentDic["height"] as? CGFloat) ?? 0
      }
      
      override func conversationDigest() -> String {
          return "[图片]"
      }
  }
  ```
</CodeGroup>

#### 第三步：注册

<CodeGroup>
  ```objc Objective-C theme={null}
  [[WKSDK shared] registerMessageContent:WKImageContent.class];
  ```

  ```swift Swift theme={null}
  WKSDK.shared().registerMessageContent(WKImageContent.self)
  ```
</CodeGroup>

### 完整图片消息实现示例

```objc theme={null}
@interface WKCustomImageContent : WKMediaMessageContent

@property(nonatomic, assign) CGFloat width;
@property(nonatomic, assign) CGFloat height;
@property(nonatomic, strong) NSData *imageData;
@property(nonatomic, copy) NSString *thumbnail; // 缩略图
@property(nonatomic, assign) NSInteger originalSize; // 原始文件大小
@property(nonatomic, assign) NSInteger compressedSize; // 压缩后大小

@end

@implementation WKCustomImageContent

- (NSNumber*)contentType {
    return @(104); // 自定义图片消息类型
}

- (void)writeDataToLocalPath {
    [super writeDataToLocalPath];
    
    if (self.imageData && self.localPath) {
        // 保存原始图片
        [self.imageData writeToFile:self.localPath atomically:YES];
        
        // 生成缩略图
        [self generateThumbnail];
    }
}

- (void)generateThumbnail {
    if (!self.imageData) return;
    
    UIImage *image = [UIImage imageWithData:self.imageData];
    if (!image) return;
    
    // 生成缩略图
    CGSize thumbnailSize = CGSizeMake(200, 200);
    UIGraphicsBeginImageContextWithOptions(thumbnailSize, NO, 0.0);
    [image drawInRect:CGRectMake(0, 0, thumbnailSize.width, thumbnailSize.height)];
    UIImage *thumbnailImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    if (thumbnailImage) {
        NSData *thumbnailData = UIImageJPEGRepresentation(thumbnailImage, 0.7);
        self.thumbnail = [thumbnailData base64EncodedStringWithOptions:0];
    }
}

- (NSDictionary *)encodeWithJSON {
    NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
    [dataDict setObject:self.remoteUrl ?: @"" forKey:@"url"];
    [dataDict setObject:@(self.width) forKey:@"width"];
    [dataDict setObject:@(self.height) forKey:@"height"];
    
    if (self.thumbnail) {
        [dataDict setObject:self.thumbnail forKey:@"thumbnail"];
    }
    if (self.originalSize > 0) {
        [dataDict setObject:@(self.originalSize) forKey:@"original_size"];
    }
    if (self.compressedSize > 0) {
        [dataDict setObject:@(self.compressedSize) forKey:@"compressed_size"];
    }
    
    return dataDict;
}

- (void)decodeWithJSON:(NSDictionary *)contentDic {
    self.remoteUrl = contentDic[@"url"];
    self.width = contentDic[@"width"] ? [contentDic[@"width"] floatValue] : 0;
    self.height = contentDic[@"height"] ? [contentDic[@"height"] floatValue] : 0;
    self.thumbnail = contentDic[@"thumbnail"];
    self.originalSize = contentDic[@"original_size"] ? [contentDic[@"original_size"] integerValue] : 0;
    self.compressedSize = contentDic[@"compressed_size"] ? [contentDic[@"compressed_size"] integerValue] : 0;
}

- (NSString *)conversationDigest {
    return @"[图片]";
}

- (NSString *)searchableWord {
    return @"[图片] [照片] [image]";
}

- (BOOL)isValid {
    return (self.imageData != nil || self.remoteUrl.length > 0) && self.width > 0 && self.height > 0;
}

@end

// 注册自定义图片消息类型
[[WKSDK shared] registerMessageContent:WKCustomImageContent.class];

// 发送自定义图片消息
- (void)sendCustomImageMessage:(WKChannel *)channel image:(UIImage *)image {
    WKCustomImageContent *imageContent = [[WKCustomImageContent alloc] init];
    imageContent.imageData = UIImageJPEGRepresentation(image, 0.8);
    imageContent.width = image.size.width;
    imageContent.height = image.size.height;
    imageContent.originalSize = imageContent.imageData.length;
    
    if ([imageContent isValid]) {
        [[WKSDK shared].chatManager sendMessage:imageContent channel:channel];
    }
}
```

## 高级消息类型示例

### 位置消息

```objc theme={null}
@interface WKLocationContent : WKMessageContent

@property(nonatomic, assign) double latitude;   // 纬度
@property(nonatomic, assign) double longitude;  // 经度
@property(nonatomic, copy) NSString *address;   // 地址描述
@property(nonatomic, copy) NSString *title;     // 位置标题

@end

@implementation WKLocationContent

- (NSNumber*)contentType {
    return @(102);
}

- (NSDictionary *)encodeWithJSON {
    NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
    [dataDict setObject:@(self.latitude) forKey:@"latitude"];
    [dataDict setObject:@(self.longitude) forKey:@"longitude"];
    [dataDict setObject:self.address ?: @"" forKey:@"address"];
    if (self.title) {
        [dataDict setObject:self.title forKey:@"title"];
    }
    return dataDict;
}

- (void)decodeWithJSON:(NSDictionary *)contentDic {
    self.latitude = contentDic[@"latitude"] ? [contentDic[@"latitude"] doubleValue] : 0;
    self.longitude = contentDic[@"longitude"] ? [contentDic[@"longitude"] doubleValue] : 0;
    self.address = contentDic[@"address"];
    self.title = contentDic[@"title"];
}

- (NSString *)conversationDigest {
    return [NSString stringWithFormat:@"[位置] %@", self.title ?: self.address];
}

- (BOOL)isValid {
    return self.latitude != 0 && self.longitude != 0 && self.address.length > 0;
}

@end

// 注册位置消息
[[WKSDK shared] registerMessageContent:WKLocationContent.class];
```

### 名片消息

```objc theme={null}
@interface WKContactCardContent : WKMessageContent

@property(nonatomic, copy) NSString *uid;        // 用户ID
@property(nonatomic, copy) NSString *name;       // 用户名称
@property(nonatomic, copy) NSString *avatar;     // 用户头像
@property(nonatomic, copy) NSString *phone;      // 电话号码
@property(nonatomic, copy) NSString *email;      // 邮箱地址

@end

@implementation WKContactCardContent

- (NSNumber*)contentType {
    return @(103);
}

- (NSDictionary *)encodeWithJSON {
    NSMutableDictionary *dataDict = [NSMutableDictionary dictionary];
    [dataDict setObject:self.uid ?: @"" forKey:@"uid"];
    [dataDict setObject:self.name ?: @"" forKey:@"name"];
    [dataDict setObject:self.avatar ?: @"" forKey:@"avatar"];
    if (self.phone) {
        [dataDict setObject:self.phone forKey:@"phone"];
    }
    if (self.email) {
        [dataDict setObject:self.email forKey:@"email"];
    }
    return dataDict;
}

- (void)decodeWithJSON:(NSDictionary *)contentDic {
    self.uid = contentDic[@"uid"];
    self.name = contentDic[@"name"];
    self.avatar = contentDic[@"avatar"];
    self.phone = contentDic[@"phone"];
    self.email = contentDic[@"email"];
}

- (NSString *)conversationDigest {
    return [NSString stringWithFormat:@"[名片] %@", self.name];
}

- (BOOL)isValid {
    return self.uid.length > 0 && self.name.length > 0;
}

@end

// 注册名片消息
[[WKSDK shared] registerMessageContent:WKContactCardContent.class];
```

## 消息类型管理器

```objc theme={null}
@interface MessageTypeManager : NSObject

+ (instancetype)sharedManager;
- (void)registerMessageType:(Class)messageClass;
- (void)registerMultipleMessageTypes:(NSArray<Class> *)messageClasses;
- (NSArray<NSNumber *> *)getRegisteredTypes;
- (BOOL)isTypeRegistered:(NSInteger)type;

@end

@implementation MessageTypeManager

+ (instancetype)sharedManager {
    static MessageTypeManager *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[MessageTypeManager alloc] init];
    });
    return instance;
}

- (instancetype)init {
    self = [super init];
    if (self) {
        _registeredTypes = [NSMutableSet set];
    }
    return self;
}

- (void)registerMessageType:(Class)messageClass {
    if ([messageClass isSubclassOfClass:[WKMessageContent class]]) {
        [[WKSDK shared] registerMessageContent:messageClass];
        
        // 获取消息类型
        WKMessageContent *content = [[messageClass alloc] init];
        NSNumber *type = [content contentType];
        [self.registeredTypes addObject:type];
        
        NSLog(@"注册消息类型: %@ (type: %@)", NSStringFromClass(messageClass), type);
    }
}

- (void)registerMultipleMessageTypes:(NSArray<Class> *)messageClasses {
    for (Class messageClass in messageClasses) {
        [self registerMessageType:messageClass];
    }
}

- (NSArray<NSNumber *> *)getRegisteredTypes {
    return [self.registeredTypes allObjects];
}

- (BOOL)isTypeRegistered:(NSInteger)type {
    return [self.registeredTypes containsObject:@(type)];
}

@end

// 使用示例
MessageTypeManager *manager = [MessageTypeManager sharedManager];

// 批量注册自定义消息类型
[manager registerMultipleMessageTypes:@[
    WKGIFContent.class,
    WKLocationContent.class,
    WKCustomImageContent.class,
    WKContactCardContent.class
]];

// 检查消息类型
NSArray *registeredTypes = [manager getRegisteredTypes];
NSLog(@"已注册的消息类型: %@", registeredTypes);
```

## 下一步

<CardGroup cols={2}>
  <Card title="多媒体管理" icon="file-image" href="/zh/sdk/wukongim/ios/media">
    回到多媒体管理功能
  </Card>

  <Card title="会话管理" icon="users" href="/zh/sdk/wukongim/ios/conversation">
    回到会话管理功能
  </Card>

  <Card title="频道管理" icon="hash" href="/zh/sdk/wukongim/ios/channel">
    回到频道管理功能
  </Card>

  <Card title="聊天管理" icon="message-circle" href="/zh/sdk/wukongim/ios/chat">
    回到聊天管理功能
  </Card>
</CardGroup>

## 总结

iOS SDK 现已完成所有核心功能文档：

✅ **集成指南** - 完整的安装和配置指导\
✅ **连接管理** - 连接状态和网络管理\
✅ **聊天管理** - 消息收发和历史消息\
✅ **频道管理** - 频道信息和成员管理\
✅ **会话管理** - 会话列表和未读消息\
✅ **多媒体管理** - 文件上传下载和进度管理\
✅ **高级功能** - 自定义消息和扩展特性

iOS SDK 文档已全面完成，为开发者提供了从入门到高级的完整技术指导！🎉