diff --git a/Realtime/Internal/Controller/LCIMMessageController.cs b/Realtime/Internal/Controller/LCIMMessageController.cs
index 8378080..71707a5 100644
--- a/Realtime/Internal/Controller/LCIMMessageController.cs
+++ b/Realtime/Internal/Controller/LCIMMessageController.cs
@@ -32,7 +32,7 @@ namespace LeanCloud.Realtime.Internal.Controller {
             } else if (message is LCIMBinaryMessage binaryMessage) {
                 direct.BinaryMsg = ByteString.CopyFrom(binaryMessage.Data);
             } else {
-                throw new ArgumentException("Message MUST BE LCIMTypedMessage or LCIMBinaryMessage.");
+                throw new ArgumentException("Message MUST be LCIMTypedMessage or LCIMBinaryMessage.");
             }
             // 暂态消息
             if (options.Transient) {
diff --git a/Realtime/Message/LCIMAudioMessage.cs b/Realtime/Message/LCIMAudioMessage.cs
index fbc28e5..ead335e 100644
--- a/Realtime/Message/LCIMAudioMessage.cs
+++ b/Realtime/Message/LCIMAudioMessage.cs
@@ -2,14 +2,15 @@
 using LeanCloud.Storage;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 音频消息
+    /// </summary>
     public class LCIMAudioMessage : LCIMFileMessage {
+        /// <summary>
+        /// 时长
+        /// </summary>
         public double Duration {
-            get {
-                if (double.TryParse(File.MetaData["duration"] as string, out double duration)) {
-                    return duration;
-                }
-                return 0;
-            }
+            get; private set;
         }
 
         internal LCIMAudioMessage() {
@@ -21,14 +22,22 @@ namespace LeanCloud.Realtime {
 
         internal override Dictionary<string, object> Encode() {
             Dictionary<string, object> data = base.Encode();
-            Dictionary<string, object> fileData = data["_lcfile"] as Dictionary<string, object>;
-            Dictionary<string, object> metaData = fileData["metaData"] as Dictionary<string, object>;
-            if (File.MetaData.TryGetValue("duration", out object duration)) {
-                metaData["duration"] = duration;
+            Dictionary<string, object> fileData = data[MessageFileKey] as Dictionary<string, object>;
+            Dictionary<string, object> metaData = fileData[MessageDataMetaDataKey] as Dictionary<string, object>;
+            if (File.MetaData.TryGetValue(MessageDataMetaDurationKey, out object duration)) {
+                metaData[MessageDataMetaDurationKey] = duration;
             }
             return data;
         }
 
-        internal override int MessageType => AudioMessageType;
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+            if (File.MetaData.TryGetValue(MessageDataMetaDurationKey, out object duration) &&
+                double.TryParse(duration as string, out double d)) {
+                Duration = d;
+            }
+        }
+
+        public override int MessageType => AudioMessageType;
     }
 }
diff --git a/Realtime/Message/LCIMBinaryMessage.cs b/Realtime/Message/LCIMBinaryMessage.cs
index d0af326..d8d76fa 100644
--- a/Realtime/Message/LCIMBinaryMessage.cs
+++ b/Realtime/Message/LCIMBinaryMessage.cs
@@ -1,5 +1,11 @@
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 二进制消息
+    /// </summary>
     public class LCIMBinaryMessage : LCIMMessage {
+        /// <summary>
+        /// 消息数据
+        /// </summary>
         public byte[] Data {
             get; internal set;
         }
diff --git a/Realtime/Message/LCIMFileMessage.cs b/Realtime/Message/LCIMFileMessage.cs
index 55aad4d..27c82b5 100644
--- a/Realtime/Message/LCIMFileMessage.cs
+++ b/Realtime/Message/LCIMFileMessage.cs
@@ -3,29 +3,41 @@ using System.Collections.Generic;
 using LeanCloud.Storage;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 文件消息
+    /// </summary>
     public class LCIMFileMessage : LCIMTextMessage {
+        /// <summary>
+        /// 文件
+        /// </summary>
         public LCFile File {
             get; set;
         }
 
+        /// <summary>
+        /// 文件大小
+        /// </summary>
         public int Size {
             get {
-                if (int.TryParse(File.MetaData["size"] as string, out int size)) {
+                if (int.TryParse(File.MetaData[MessageDataMetaSizeKey] as string, out int size)) {
                     return size;
                 }
                 return 0;
             }
         }
 
+        /// <summary>
+        /// 文件类型
+        /// </summary>
         public string Format {
             get {
-                if (File.MetaData.TryGetValue("format", out object format)) {
-                    return format as string;
-                }
-                return "unknown/unknown";
+                return File.MimeType;
             }
         }
 
+        /// <summary>
+        /// 文件链接
+        /// </summary>
         public string Url {
             get {
                 return File.Url;
@@ -40,41 +52,46 @@ namespace LeanCloud.Realtime {
             File = file;
         }
 
-        internal override int MessageType => FileMessageType;
+        public override int MessageType => FileMessageType;
 
         internal override Dictionary<string, object> Encode() {
             if (File == null) {
                 throw new Exception("File MUST NOT be null before sent.");
             }
             Dictionary<string, object> fileData = new Dictionary<string, object> {
-                { "objId", File.ObjectId },
-                { "url", File.Url },
-                { "metaData", new Dictionary<string, object> {
-                    { "name", File.Name },
-                    { "format", File.MimeType }
+                { MessageDataObjectIdKey, File.ObjectId },
+                { MessageDataUrlKey, File.Url },
+                { MessageDataMetaDataKey, new Dictionary<string, object> {
+                    { MessageDataMetaNameKey, File.Name },
+                    { MessageDataMetaFormatKey, File.MimeType }
                 } }
             };
-            if (File.MetaData.TryGetValue("size", out object size)) {
-                Dictionary<string, object> metaData = fileData["metaData"] as Dictionary<string, object>;
-                metaData["size"] = size;
+            if (File.MetaData.TryGetValue(MessageDataMetaSizeKey, out object size)) {
+                Dictionary<string, object> metaData = fileData[MessageDataMetaDataKey] as Dictionary<string, object>;
+                metaData[MessageDataMetaSizeKey] = size;
             }
             Dictionary<string, object> data = base.Encode();
-            data["_lcfile"] = fileData;
+            data[MessageFileKey] = fileData;
             return data;
         }
 
-        protected override void DecodeMessageData(Dictionary<string, object> msgData) {
-            base.DecodeMessageData(msgData);
-            Dictionary<string, object> fileData = msgData["_lcfile"] as Dictionary<string, object>;
-            string objectId = fileData["objId"] as string;
-            File = LCObject.CreateWithoutData(LCFile.CLASS_NAME, objectId) as LCFile;
-            if (fileData.TryGetValue("url", out object url)) {
-                File.Url = url as string;
-            }
-            if (fileData.TryGetValue("metaData", out object metaData)) {
-                File.MetaData = metaData as Dictionary<string, object>;
-                if (File.MetaData.TryGetValue("name", out object name)) {
-                    File.Name = name as string;
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+
+            if (msgData.TryGetValue(MessageFileKey, out object fileDataObject)) {
+                Dictionary<string, object> fileData = fileDataObject as Dictionary<string, object>;
+                if (fileData.TryGetValue(MessageDataObjectIdKey, out object objectIdObject)) {
+                    string objectId = objectIdObject as string;
+                    File = LCObject.CreateWithoutData(LCFile.CLASS_NAME, objectId) as LCFile;
+                    if (fileData.TryGetValue(MessageDataUrlKey, out object url)) {
+                        File.Url = url as string;
+                    }
+                    if (fileData.TryGetValue(MessageDataMetaDataKey, out object metaData)) {
+                        File.MetaData = metaData as Dictionary<string, object>;
+                        if (File.MetaData.TryGetValue(MessageDataMetaNameKey, out object name)) {
+                            File.Name = name as string;
+                        }
+                    }
                 }
             }
         }
diff --git a/Realtime/Message/LCIMImageMessage.cs b/Realtime/Message/LCIMImageMessage.cs
index fcf59ef..7d116d2 100644
--- a/Realtime/Message/LCIMImageMessage.cs
+++ b/Realtime/Message/LCIMImageMessage.cs
@@ -2,23 +2,22 @@
 using LeanCloud.Storage;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 图像消息
+    /// </summary>
     public class LCIMImageMessage : LCIMFileMessage {
+        /// <summary>
+        /// 图像宽度
+        /// </summary>
         public int Width {
-            get {
-                if (int.TryParse(File.MetaData["width"] as string, out int width)) {
-                    return width;
-                }
-                return 0;
-            }
+            get; private set;
         }
 
+        /// <summary>
+        /// 图像高度
+        /// </summary>
         public int Height {
-            get {
-                if (int.TryParse(File.MetaData["height"] as string, out int height)) {
-                    return height;
-                }
-                return 0;
-            }
+            get; private set;
         }
 
         internal LCIMImageMessage() : base() {
@@ -30,17 +29,29 @@ namespace LeanCloud.Realtime {
 
         internal override Dictionary<string, object> Encode() {
             Dictionary<string, object> data = base.Encode();
-            Dictionary<string, object> fileData = data["_lcfile"] as Dictionary<string, object>;
-            Dictionary<string, object> metaData = fileData["metaData"] as Dictionary<string, object>;
-            if (File.MetaData.TryGetValue("width", out object width)) {
-                metaData["width"] = width;
+            Dictionary<string, object> fileData = data[MessageFileKey] as Dictionary<string, object>;
+            Dictionary<string, object> metaData = fileData[MessageDataMetaDataKey] as Dictionary<string, object>;
+            if (File.MetaData.TryGetValue(MessageDataMetaWidthKey, out object width)) {
+                metaData[MessageDataMetaWidthKey] = width;
             }
-            if (File.MetaData.TryGetValue("height", out object height)) {
-                metaData["height"] = height;
+            if (File.MetaData.TryGetValue(MessageDataMetaHeightKey, out object height)) {
+                metaData[MessageDataMetaHeightKey] = height;
             }
             return data;
         }
 
-        internal override int MessageType => ImageMessageType;
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+            if (File.MetaData.TryGetValue(MessageDataMetaWidthKey, out object width) &&
+                int.TryParse(width as string, out int w)) {
+                Width = w;
+            }
+            if (File.MetaData.TryGetValue(MessageDataMetaHeightKey, out object height) &&
+                int.TryParse(height as string, out int h)) {
+                Height = h;
+            }
+        }
+
+        public override int MessageType => ImageMessageType;
     }
 }
diff --git a/Realtime/Message/LCIMLocationMessage.cs b/Realtime/Message/LCIMLocationMessage.cs
index ffe60c1..310da36 100644
--- a/Realtime/Message/LCIMLocationMessage.cs
+++ b/Realtime/Message/LCIMLocationMessage.cs
@@ -2,7 +2,13 @@
 using LeanCloud.Storage;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 位置消息
+    /// </summary>
     public class LCIMLocationMessage : LCIMTextMessage {
+        /// <summary>
+        /// 位置
+        /// </summary>
         public LCGeoPoint Location {
             get; set;
         }
@@ -17,19 +23,30 @@ namespace LeanCloud.Realtime {
         internal override Dictionary<string, object> Encode() {
             Dictionary<string, object> data = base.Encode();
             Dictionary<string, object> locationData = new Dictionary<string, object> {
-                { "longitude", Location.Longitude },
-                { "latitude", Location.Latitude }
+                { MessageDataLongitudeKey, Location.Longitude },
+                { MessageDataLatitudeKey, Location.Latitude }
             };
-            data["_lcloc"] = locationData;
+            data[MessageLocationKey] = locationData;
             return data;
         }
 
-        protected override void DecodeMessageData(Dictionary<string, object> msgData) {
-            base.DecodeMessageData(msgData);
-            Dictionary<string, object> locationData = msgData["_lcloc"] as Dictionary<string, object>;
-            Location = new LCGeoPoint((double)locationData["latitude"], (double)locationData["longitude"]);
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+            if (msgData.TryGetValue(MessageLocationKey, out object val)) {
+                Dictionary<string, object> locationData = val as Dictionary<string, object>;
+                double latitude = 0, longitude = 0;
+                if (locationData.TryGetValue(MessageDataLatitudeKey, out object lat) &&
+                    double.TryParse(lat as string, out double la)) {
+                    latitude = la;
+                }
+                if (locationData.TryGetValue(MessageDataLongitudeKey, out object lon) &&
+                    double.TryParse(lon as string, out double lo)) {
+                    longitude = lo;
+                }
+                Location = new LCGeoPoint(latitude, longitude);
+            }
         }
 
-        internal override int MessageType => LocationMessageType;
+        public override int MessageType => LocationMessageType;
     }
 }
diff --git a/Realtime/Message/LCIMMessage.cs b/Realtime/Message/LCIMMessage.cs
index 77fc128..e62fbcb 100644
--- a/Realtime/Message/LCIMMessage.cs
+++ b/Realtime/Message/LCIMMessage.cs
@@ -2,31 +2,41 @@
 using System.Collections.Generic;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 消息基类
+    /// </summary>
     public abstract class LCIMMessage {
-        internal const int TextMessageType = -1;
-        internal const int ImageMessageType = -2;
-        internal const int AudioMessageType = -3;
-        internal const int VideoMessageType = -4;
-        internal const int LocationMessageType = -5;
-        internal const int FileMessageType = -6;
-        internal const int RecalledMessageType = -127;
-            
+        /// <summary>
+        /// 消息所在对话 Id
+        /// </summary>
         public string ConversationId {
             get; set;
         }
 
+        /// <summary>
+        /// 消息 Id
+        /// </summary>
         public string Id {
             get; set;
         }
 
+        /// <summary>
+        /// 发送者 Id
+        /// </summary>
         public string FromClientId {
             get; set;
         }
 
+        /// <summary>
+        /// 发送时间戳
+        /// </summary>
         public long SentTimestamp {
             get; internal set;
         }
 
+        /// <summary>
+        /// 发送时间
+        /// </summary>
         public DateTime SentAt {
             get {
                 return DateTimeOffset.FromUnixTimeMilliseconds(SentTimestamp)
@@ -34,10 +44,16 @@ namespace LeanCloud.Realtime {
             }
         }
 
+        /// <summary>
+        /// 送达时间戳
+        /// </summary>
         public long DeliveredTimestamp {
             get; internal set;
         }
 
+        /// <summary>
+        /// 送达时间
+        /// </summary>
         public DateTime DeliveredAt {
             get {
                 return DateTimeOffset.FromUnixTimeMilliseconds(DeliveredTimestamp)
@@ -45,10 +61,16 @@ namespace LeanCloud.Realtime {
             }
         }
 
+        /// <summary>
+        /// 已读时间戳
+        /// </summary>
         public long ReadTimestamp {
             get; internal set;
         }
 
+        /// <summary>
+        /// 已读时间
+        /// </summary>
         public DateTime ReadAt {
             get {
                 return DateTimeOffset.FromUnixTimeMilliseconds(ReadTimestamp)
@@ -56,10 +78,16 @@ namespace LeanCloud.Realtime {
             }
         }
 
+        /// <summary>
+        /// 修改时间戳
+        /// </summary>
         public long PatchedTimestamp {
             get; internal set;
         }
 
+        /// <summary>
+        /// 修改时间
+        /// </summary>
         public DateTime PatchedAt {
             get {
                 return DateTimeOffset.FromUnixTimeMilliseconds(PatchedTimestamp)
@@ -67,18 +95,30 @@ namespace LeanCloud.Realtime {
             }
         }
 
+        /// <summary>
+        /// 提醒成员 Id 列表
+        /// </summary>
         public List<string> MentionIdList {
             get; set;
         }
 
+        /// <summary>
+        /// 是否提醒所有人
+        /// </summary>
         public bool MentionAll {
             get; set;
         }
 
+        /// <summary>
+        /// 是否提醒当前用户
+        /// </summary>
         public bool Mentioned {
             get; internal set;
         }
 
+        /// <summary>
+        /// 是否是暂态消息
+        /// </summary>
         public bool IsTransient {
             get; internal set;
         }
diff --git a/Realtime/Message/LCIMRecalledMessage.cs b/Realtime/Message/LCIMRecalledMessage.cs
index 3706dda..352e585 100644
--- a/Realtime/Message/LCIMRecalledMessage.cs
+++ b/Realtime/Message/LCIMRecalledMessage.cs
@@ -7,6 +7,6 @@ namespace LeanCloud.Realtime {
         public LCIMRecalledMessage() {
         }
 
-        internal override int MessageType => RecalledMessageType;
+        public override int MessageType => RecalledMessageType;
     }
 }
diff --git a/Realtime/Message/LCIMTextMessage.cs b/Realtime/Message/LCIMTextMessage.cs
index 8a8ba8c..65244cb 100644
--- a/Realtime/Message/LCIMTextMessage.cs
+++ b/Realtime/Message/LCIMTextMessage.cs
@@ -1,7 +1,13 @@
 using System.Collections.Generic;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 文本消息
+    /// </summary>
     public class LCIMTextMessage : LCIMTypedMessage {
+        /// <summary>
+        /// 文本
+        /// </summary>
         public string Text {
             get; set;
         }
@@ -16,16 +22,16 @@ namespace LeanCloud.Realtime {
         internal override Dictionary<string, object> Encode() {
             Dictionary<string, object> data = base.Encode();
             if (!string.IsNullOrEmpty(Text)) {
-                data["_lctext"] = Text;
+                data[MessageTextKey] = Text;
             }
             return data;
         }
 
-        internal override int MessageType => TextMessageType;
+        public override int MessageType => TextMessageType;
 
-        protected override void DecodeMessageData(Dictionary<string, object> msgData) {
-            base.DecodeMessageData(msgData);
-            if (msgData.TryGetValue("_lctext", out object value)) {
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+            if (msgData.TryGetValue(MessageTextKey, out object value)) {
                 Text = value as string;
             }
         }
diff --git a/Realtime/Message/LCIMTypedMessage.cs b/Realtime/Message/LCIMTypedMessage.cs
index 08a5d6d..3c1b677 100644
--- a/Realtime/Message/LCIMTypedMessage.cs
+++ b/Realtime/Message/LCIMTypedMessage.cs
@@ -1,16 +1,85 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using Newtonsoft.Json;
 using LeanCloud.Storage.Internal.Codec;
 using LeanCloud.Storage.Internal;
 
 namespace LeanCloud.Realtime {
-    public abstract class LCIMTypedMessage : LCIMMessage {
+    /// <summary>
+    /// 已知类型消息
+    /// </summary>
+    public class LCIMTypedMessage : LCIMMessage {
+        /// <summary>
+        /// 文本消息
+        /// </summary>
+        public const int TextMessageType = -1;
+        /// <summary>
+        /// 图像消息
+        /// </summary>
+        public const int ImageMessageType = -2;
+        /// <summary>
+        /// 音频消息
+        /// </summary>
+        public const int AudioMessageType = -3;
+        /// <summary>
+        /// 视频消息
+        /// </summary>
+        public const int VideoMessageType = -4;
+        /// <summary>
+        /// 位置消息
+        /// </summary>
+        public const int LocationMessageType = -5;
+        /// <summary>
+        /// 文件消息
+        /// </summary>
+        public const int FileMessageType = -6;
+        /// <summary>
+        /// 撤回消息
+        /// </summary>
+        public const int RecalledMessageType = -127;
+
+        /// <summary>
+        /// 保留字段
+        /// </summary>
+        protected const string MessageTypeKey = "_lctype";
+        protected const string MessageAttributesKey = "_lcattrs";
+        protected const string MessageTextKey = "_lctext";
+        protected const string MessageLocationKey = "_lcloc";
+        protected const string MessageFileKey = "_lcfile";
+
+        protected const string MessageDataLongitudeKey = "longitude";
+        protected const string MessageDataLatitudeKey = "latitude";
+        
+        protected const string MessageDataObjectIdKey = "objId";
+        protected const string MessageDataUrlKey = "url";
+        protected const string MessageDataMetaDataKey = "metaData";
+        protected const string MessageDataMetaNameKey = "name";
+        protected const string MessageDataMetaFormatKey = "format";
+        protected const string MessageDataMetaSizeKey = "size";
+        protected const string MessageDataMetaWidthKey = "width";
+        protected const string MessageDataMetaHeightKey = "height";
+        protected const string MessageDataMetaDurationKey = "duration";
+
+
         private Dictionary<string, object> customProperties;
 
-        internal virtual int MessageType {
+        /// <summary>
+        /// 完整的消息数据
+        /// </summary>
+        protected Dictionary<string, object> data = new Dictionary<string, object>();
+
+        /// <summary>
+        /// 消息类型
+        /// </summary>
+        public virtual int MessageType {
             get; private set;
         }
 
+        /// <summary>
+        /// 消息属性访问
+        /// </summary>
+        /// <param name="key"></param>
+        /// <returns></returns>
         public object this[string key] {
             get {
                 if (customProperties == null) {
@@ -30,18 +99,19 @@ namespace LeanCloud.Realtime {
         }
 
         internal virtual Dictionary<string, object> Encode() {
-            Dictionary<string, object> msgData = new Dictionary<string, object> {
-                { "_lctype", MessageType }
-            };
+            Dictionary<string, object> msgData = data != null ?
+                new Dictionary<string, object>(data) : new Dictionary<string, object>();
+            msgData[MessageTypeKey] = MessageType;
             if (customProperties != null && customProperties.Count > 0) {
-                msgData["_lcattrs"] = LCEncoder.Encode(customProperties);
+                msgData[MessageAttributesKey] = LCEncoder.Encode(customProperties);
             }
             return msgData;
         }
 
-        protected virtual void DecodeMessageData(Dictionary<string, object> msgData) {
-            MessageType = (int)msgData["_lctype"];
-            if (msgData.TryGetValue("_lcattrs", out object attrObj)) {
+        internal virtual void Decode(Dictionary<string, object> msgData) {
+            data = msgData;
+            MessageType = (int)msgData[MessageTypeKey];
+            if (msgData.TryGetValue(MessageAttributesKey, out object attrObj)) {
                 customProperties = LCDecoder.Decode(attrObj) as Dictionary<string, object>;
             }
         }
@@ -50,36 +120,38 @@ namespace LeanCloud.Realtime {
             Dictionary<string, object> msgData = JsonConvert.DeserializeObject<Dictionary<string, object>>(json,
                 new LCJsonConverter());
             LCIMTypedMessage message = null;
-            int msgType = (int)msgData["_lctype"];
-            switch (msgType) {
-                case TextMessageType:
-                    message = new LCIMTextMessage();
-                    break;
-                case ImageMessageType:
-                    message = new LCIMImageMessage();
-                    break;
-                case AudioMessageType:
-                    message = new LCIMAudioMessage();
-                    break;
-                case VideoMessageType:
-                    message = new LCIMVideoMessage();
-                    break;
-                case LocationMessageType:
-                    message = new LCIMLocationMessage();
-                    break;
-                case FileMessageType:
-                    message = new LCIMFileMessage();
-                    break;
-                case RecalledMessageType:
-                    message = new LCIMRecalledMessage();
-                    break;
-                default:
-                    // TODO 用户自定义类型消息
-
-                    break;
+            int msgType = (int)msgData[MessageTypeKey];
+            if (customMessageDict.TryGetValue(msgType, out Func<LCIMTypedMessage> msgConstructor)) {
+                // 已注册的类型消息
+                message = msgConstructor.Invoke();
+            } else {
+                // 未注册的类型消息
+                message = new LCIMTypedMessage();
             }
-            message.DecodeMessageData(msgData);
+            message.Decode(msgData);
             return message;
         }
+
+        // 内置已知类型消息
+        static readonly Dictionary<int, Func<LCIMTypedMessage>> customMessageDict = new Dictionary<int, Func<LCIMTypedMessage>> {
+            { TextMessageType, () => new LCIMTextMessage() },
+            { ImageMessageType, () => new LCIMImageMessage() },
+            { AudioMessageType, () => new LCIMAudioMessage() },
+            { VideoMessageType, () => new LCIMVideoMessage() },
+            { LocationMessageType, () => new LCIMLocationMessage() },
+            { FileMessageType, () => new LCIMFileMessage() },
+            { RecalledMessageType, () => new LCIMRecalledMessage() }
+        };
+
+        /// <summary>
+        /// 注册自定义类型消息
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="msgType"></param>
+        /// <param name="msgConstructor"></param>
+        public static void Register<T>(int msgType, Func<T> msgConstructor)
+            where T : LCIMTypedMessage {
+            customMessageDict[msgType] = msgConstructor;
+        }
     }
 }
diff --git a/Realtime/Message/LCIMVideoMessage.cs b/Realtime/Message/LCIMVideoMessage.cs
index 9754dd6..09f6a91 100644
--- a/Realtime/Message/LCIMVideoMessage.cs
+++ b/Realtime/Message/LCIMVideoMessage.cs
@@ -2,14 +2,29 @@
 using LeanCloud.Storage;
 
 namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 视频消息
+    /// </summary>
     public class LCIMVideoMessage : LCIMFileMessage {
+        /// <summary>
+        /// 宽度
+        /// </summary>
+        public int Width {
+            get; private set;
+        }
+
+        /// <summary>
+        /// 高度
+        /// </summary>
+        public int Height {
+            get; private set;
+        }
+
+        /// <summary>
+        /// 时长
+        /// </summary>
         public double Duration {
-            get {
-                if (double.TryParse(File.MetaData["duration"] as string, out double duration)) {
-                    return duration;
-                }
-                return 0;
-            }
+            get; private set;
         }
 
         internal LCIMVideoMessage() {
@@ -21,20 +36,36 @@ namespace LeanCloud.Realtime {
 
         internal override Dictionary<string, object> Encode() {
             Dictionary<string, object> data = base.Encode();
-            Dictionary<string, object> fileData = data["_lcfile"] as Dictionary<string, object>;
-            Dictionary<string, object> metaData = fileData["metaData"] as Dictionary<string, object>;
-            if (File.MetaData.TryGetValue("width", out object width)) {
-                metaData["width"] = width;
+            Dictionary<string, object> fileData = data[MessageFileKey] as Dictionary<string, object>;
+            Dictionary<string, object> metaData = fileData[MessageDataMetaDataKey] as Dictionary<string, object>;
+            if (File.MetaData.TryGetValue(MessageDataMetaWidthKey, out object width)) {
+                metaData[MessageDataMetaWidthKey] = width;
             }
-            if (File.MetaData.TryGetValue("height", out object height)) {
-                metaData["height"] = height;
+            if (File.MetaData.TryGetValue(MessageDataMetaHeightKey, out object height)) {
+                metaData[MessageDataMetaHeightKey] = height;
             }
-            if (File.MetaData.TryGetValue("duration", out object duration)) {
-                metaData["duration"] = duration;
+            if (File.MetaData.TryGetValue(MessageDataMetaDurationKey, out object duration)) {
+                metaData[MessageDataMetaDurationKey] = duration;
             }
             return data;
         }
 
-        internal override int MessageType => VideoMessageType;
+        internal override void Decode(Dictionary<string, object> msgData) {
+            base.Decode(msgData);
+            if (File.MetaData.TryGetValue(MessageDataMetaWidthKey, out object width) &&
+                int.TryParse(width as string, out int w)) {
+                Width = w;
+            }
+            if (File.MetaData.TryGetValue(MessageDataMetaHeightKey, out object height) &&
+                int.TryParse(height as string, out int h)) {
+                Height = h;
+            }
+            if (File.MetaData.TryGetValue(MessageDataMetaDurationKey, out object duration) &&
+                double.TryParse(duration as string, out double d)) {
+                Duration = d;
+            }
+        }
+
+        public override int MessageType => VideoMessageType;
     }
 }