Merge branch 'feature-nxdev' of https://gitea.nxsir.cn/code/IM into feature-nxdev

backend/IM_API/Models/MessageState.cs

@@ -0,0 +1,14 @@
+namespace IM_API.Models
+{
+    public enum MessageState
+    {
+        /// <summary>
+        /// 已发送
+        /// </summary>
+        Sent = 0,
+        /// <summary>
+        /// 已撤回
+        /// </summary>
+        Withdrwan = 1
+    }
+}