diff --git a/src/HPSocket.Net/Base/Server.cs b/src/HPSocket.Net/Base/Server.cs
index 02594760ddcd1cb61c6e28247c6938005fe0c622..498e0865efd6d37aa17798153ac7db612ea9bdeb 100644
--- a/src/HPSocket.Net/Base/Server.cs
+++ b/src/HPSocket.Net/Base/Server.cs
@@ -6,8 +6,6 @@ using System.Text;
 #if !NET20 && !NET30 && !NET35
 using System.Threading.Tasks;
 using System.Collections.Concurrent;
-#else
-using System.Collections.Generic;
 #endif
 
 namespace HPSocket.Base
@@ -431,18 +429,18 @@ namespace HPSocket.Base
             return obj == null ? default : (T)obj;
         }
 
-		#if NET20 || NET30 || NET35
+#if NET20 || NET30 || NET35
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         public Dictionary<IntPtr, object> GetAllExtra()
         {
             return ExtraData.GetAll();
         }
-		#else
+#else
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         public ConcurrentDictionary<IntPtr, object> GetAllExtra()
@@ -451,7 +449,6 @@ namespace HPSocket.Base
         }
 		#endif
 
-
         /// <inheritdoc />
         public bool RemoveExtra(IntPtr connId) => ExtraData.Remove(connId);
 
diff --git a/src/HPSocket.Net/Common/ExtraData.cs b/src/HPSocket.Net/Common/ExtraData.cs
index 21e38e62397a06fc4d6d3c9409f3b12ca670f72a..125178ae33e15023cb71c42952e9ccf90ea1a53a 100644
--- a/src/HPSocket.Net/Common/ExtraData.cs
+++ b/src/HPSocket.Net/Common/ExtraData.cs
@@ -46,19 +46,16 @@ namespace HPSocket
         }
 
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         public Dictionary<TKey, TValue> GetAll()
         {
-            return _dict;
+            return new Dictionary<TKey, TValue>(_dict);
         }
 
-
-
         /// <summary>
         /// 设置附加数据
-        /// 
         /// </summary>
         /// <param name="key"></param>
         /// <param name="newValue"></param>
@@ -149,17 +146,16 @@ namespace HPSocket
         }
 
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         public ConcurrentDictionary<TKey, TValue> GetAll()
         {
-            return _dict;
+            return new ConcurrentDictionary<TKey, TValue>(_dict);
         }
 
         /// <summary>
         /// 设置附加数据
-        /// 
         /// </summary>
         /// <param name="key"></param>
         /// <param name="newValue"></param>
diff --git a/src/HPSocket.Net/HPSocket.Net.xml b/src/HPSocket.Net/HPSocket.Net.xml
index a8fdbddde796fd86b0375b300745d7bcf812bee0..c2bc5a742f6edd3e3d31cd4831bcaf2bc0fc6371 100644
--- a/src/HPSocket.Net/HPSocket.Net.xml
+++ b/src/HPSocket.Net/HPSocket.Net.xml
@@ -986,7 +986,7 @@
         </member>
         <member name="M:HPSocket.Base.Server.GetAllExtra">
             <summary>
-            获取所有扩展数据
+            获取所有附加数据
             </summary>
             <returns></returns>
         </member>
@@ -1518,14 +1518,13 @@
         </member>
         <member name="M:HPSocket.ExtraData`2.GetAll">
             <summary>
-            获取所有扩展数据
+            获取所有附加数据
             </summary>
             <returns></returns>
         </member>
         <member name="M:HPSocket.ExtraData`2.Set(`0,`1)">
             <summary>
             设置附加数据
-            
             </summary>
             <param name="key"></param>
             <param name="newValue"></param>
@@ -4419,7 +4418,7 @@
         </member>
         <member name="M:HPSocket.IServer.GetAllExtra">
             <summary>
-            获取所有扩展数据
+            获取所有附加数据
             </summary>
             <returns></returns>
         </member>
diff --git a/src/HPSocket.Net/IServer.cs b/src/HPSocket.Net/IServer.cs
index 6cf00124d9d3b3b66db3f164da3a62ce6a396f87..5aa3638ed29e14d6c1ae63c87087a1e575d46517 100644
--- a/src/HPSocket.Net/IServer.cs
+++ b/src/HPSocket.Net/IServer.cs
@@ -1,10 +1,7 @@
 using System;
 using System.Collections.Generic;
 #if !NET20 && !NET30 && !NET35
-using System.Threading.Tasks;
 using System.Collections.Concurrent;
-#else
-using System.Collections.Generic;
 #endif
 
 namespace HPSocket
@@ -339,15 +336,15 @@ namespace HPSocket
         /// <returns></returns>
         T GetExtra<T>(IntPtr connId);
 
-		#if NET20 || NET30 || NET35
+#if NET20 || NET30 || NET35
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         Dictionary<IntPtr, object> GetAllExtra();
-		#else
+#else
         /// <summary>
-        /// 获取所有扩展数据
+        /// 获取所有附加数据
         /// </summary>
         /// <returns></returns>
         ConcurrentDictionary<IntPtr, object> GetAllExtra();