* LCIMConversation.cs:

* LCIMMessageSendOptions.cs:

* LCIMMessageController.cs: chore: 支持发送消息选项

Realtime/Conversation/LCIMConversation.cs

@@ -254,11 +254,15 @@ namespace LeanCloud.Realtime {
         /// </summary>
         /// <param name="message"></param>
         /// <returns></returns>
-        public async Task<LCIMMessage> Send(LCIMMessage message) {
+        public async Task<LCIMMessage> Send(LCIMMessage message,
+            LCIMMessageSendOptions options = null) {
             if (message == null) {
                 throw new ArgumentNullException(nameof(message));
             }
-            await Client.MessageController.Send(Id, message);
+            if (options == null) {
+                options = LCIMMessageSendOptions.Default;
+            }
+            await Client.MessageController.Send(Id, message, options);
             return message;
         }
 

Realtime/Internal/Controller/LCIMMessageController.cs

@@ -21,7 +21,8 @@ namespace LeanCloud.Realtime.Internal.Controller {
         /// <param name="message"></param>
         /// <returns></returns>
         internal async Task<LCIMMessage> Send(string convId,
-            LCIMMessage message) {
+            LCIMMessage message,
+            LCIMMessageSendOptions options) {
             DirectCommand direct = new DirectCommand {
                 FromPeerId = Client.Id,
                 Cid = convId,
@@ -33,8 +34,24 @@ namespace LeanCloud.Realtime.Internal.Controller {
             } else {
                 throw new ArgumentException("Message MUST BE LCIMTypedMessage or LCIMBinaryMessage.");
             }
+            // 暂态消息
+            if (options.Transient) {
+                direct.Transient = options.Transient;
+            }
+            // 消息接收回执
+            if (options.Receipt) {
+                direct.R = options.Receipt;
+            }
+            // 遗愿消息
+            if (options.Will) {
+                direct.Will = options.Will;
+            }
             GenericCommand command = NewCommand(CommandType.Direct);
             command.DirectMessage = direct;
+            // 优先级
+            if (command.Priority > 0) {
+                command.Priority = (int)options.Priority;
+            }
             GenericCommand response = await Client.Connection.SendRequest(command);
             // 消息发送应答
             AckCommand ack = response.AckMessage;

Realtime/Message/LCIMMessageSendOptions.cs

@@ -0,0 +1,45 @@
+namespace LeanCloud.Realtime {
+    /// <summary>
+    /// 消息优先级
+    /// </summary>
+    public enum LCIMMessagePriority {
+        Hight = 1,
+        Normal = 2,
+        Low = 3
+    }
+
+    /// <summary>
+    /// 发送消息选项
+    /// </summary>
+    public class LCIMMessageSendOptions {
+        /// <summary>
+        /// 是否作为暂态消息发送
+        /// </summary>
+        public bool Transient {
+            get; set;
+        }
+
+        /// <summary>
+        /// 是否需要消息回执，仅在普通对话中有效
+        /// </summary>
+        public bool Receipt {
+            get; set;
+        }
+
+        /// <summary>
+        /// 是否作为遗愿消息发送
+        /// </summary>
+        public bool Will {
+            get; set;
+        }
+
+        /// <summary>
+        /// 消息优先级，仅在暂态对话中有效
+        /// </summary>
+        public LCIMMessagePriority Priority {
+            get; set;
+        }
+
+        public static LCIMMessageSendOptions Default = new LCIMMessageSendOptions();
+    }
+}