diff --git a/NewLife.Remoting/ApiClient.cs b/NewLife.Remoting/ApiClient.cs
index bdb3c63..9e9d24f 100644
--- a/NewLife.Remoting/ApiClient.cs
+++ b/NewLife.Remoting/ApiClient.cs
@@ -6,6 +6,9 @@
 using NewLife.Net;
 using NewLife.Remoting.Http;
 using NewLife.Threading;
+#if !NET40
+using TaskEx = System.Threading.Tasks.Task;
+#endif
 
 namespace NewLife.Remoting;
 
@@ -186,7 +189,7 @@ protected virtual ICluster<String, ISocketClient> InitCluster()
     /// <param name="action">服务操作</param>
     /// <param name="args">参数</param>
     /// <returns></returns>
-    public virtual TResult? Invoke<TResult>(String action, Object? args = null) => Task.Run(() => InvokeAsync<TResult>(action, args)).Result;
+    public virtual TResult? Invoke<TResult>(String action, Object? args = null) => TaskEx.Run(() => InvokeAsync<TResult>(action, args)).Result;
 
     /// <summary>单向发送。同步调用，不等待返回</summary>
     /// <param name="action">服务操作</param>
@@ -380,7 +383,7 @@ private void Client_Received(Object? sender, ReceivedEventArgs e)
     /// <summary>连接后自动登录</summary>
     /// <param name="client">客户端</param>
     /// <param name="force">强制登录</param>
-    protected virtual Task<Object?> OnLoginAsync(ISocketClient client, Boolean force) => Task.FromResult<Object?>(null);
+    protected virtual Task<Object?> OnLoginAsync(ISocketClient client, Boolean force) => TaskEx.FromResult<Object?>(null);
 
     /// <summary>登录</summary>
     /// <returns></returns>
diff --git a/NewLife.Remoting/ApiHttpServer.cs b/NewLife.Remoting/ApiHttpServer.cs
index bb9e3fe..a2914c2 100644
--- a/NewLife.Remoting/ApiHttpServer.cs
+++ b/NewLife.Remoting/ApiHttpServer.cs
@@ -1,6 +1,7 @@
 using NewLife.Http;
 using NewLife.Net;
 using NewLife.Remoting.Http;
+using HttpCodec = NewLife.Remoting.Http.HttpCodec;
 
 namespace NewLife.Remoting;
 
diff --git a/NewLife.Remoting/ApiNetServer.cs b/NewLife.Remoting/ApiNetServer.cs
index 4989b79..6d66deb 100644
--- a/NewLife.Remoting/ApiNetServer.cs
+++ b/NewLife.Remoting/ApiNetServer.cs
@@ -3,6 +3,7 @@
 using NewLife.Messaging;
 using NewLife.Net;
 using NewLife.Remoting.Http;
+using HttpCodec = NewLife.Remoting.Http.HttpCodec;
 
 namespace NewLife.Remoting;
 
diff --git a/NewLife.Remoting/Clients/WsChannel.cs b/NewLife.Remoting/Clients/WsChannel.cs
index 2a35b72..5399471 100644
--- a/NewLife.Remoting/Clients/WsChannel.cs
+++ b/NewLife.Remoting/Clients/WsChannel.cs
@@ -2,6 +2,9 @@
 using NewLife.Net;
 using NewLife.Remoting.Models;
 using NewLife.Serialization;
+#if !NET40
+using TaskEx = System.Threading.Tasks.Task;
+#endif
 
 namespace NewLife.Remoting.Clients;
 
@@ -65,7 +68,7 @@ public virtual async Task ValidWebSocket(ApiHttpClient http)
             _websocket = client;
 
             _source = new CancellationTokenSource();
-            _ = Task.Run(() => DoPull(client, _source.Token));
+            _ = TaskEx.Run(() => DoPull(client, _source.Token));
         }
     }
 
diff --git a/NewLife.Remoting/Http/HttpEncoder.cs b/NewLife.Remoting/Http/HttpEncoder.cs
index 7bc6d8b..c08784d 100644
--- a/NewLife.Remoting/Http/HttpEncoder.cs
+++ b/NewLife.Remoting/Http/HttpEncoder.cs
@@ -258,12 +258,12 @@ public virtual IMessage CreateResponse(IMessage msg, String action, Int32 code,
             p = url.IndexOf('?');
             if (p > 0)
             {
-                message.Action = url[1..p];
-                message.Data = url[(p + 1)..].GetBytes();
+                message.Action = url.Substring(1, p - 1);
+                message.Data = url.Substring(p + 1).GetBytes();
             }
             else
             {
-                message.Action = url[1..];
+                message.Action = url.Substring(1);
                 message.Data = http.Payload;
             }
         }
@@ -279,7 +279,7 @@ public virtual IMessage CreateResponse(IMessage msg, String action, Int32 code,
                 message.Action = uri.AbsolutePath;
                 message.Data = http.Payload;
             }
-            if (message.Action.Length > 1) message.Action = message.Action[1..];
+            if (message.Action.Length > 1) message.Action = message.Action.Substring(1);
         }
 
         return message;
diff --git a/NewLife.Remoting/JsonEncoder.cs b/NewLife.Remoting/JsonEncoder.cs
index f3294a3..318e8fa 100644
--- a/NewLife.Remoting/JsonEncoder.cs
+++ b/NewLife.Remoting/JsonEncoder.cs
@@ -95,7 +95,7 @@ public virtual Packet Encode(String action, Int32? code, Packet? value)
     public virtual IMessage CreateRequest(String action, Object? args)
     {
         // 二进制优先
-        var (pk, str) = EncodeValue(args);
+        var pk = EncodeValue(args, out var str);
 
         if (Log != null && str.IsNullOrEmpty() && pk != null) str = $"[{pk?.Total}]";
         WriteLog("{0}=>{1}", action, str);
@@ -114,7 +114,7 @@ public virtual IMessage CreateRequest(String action, Object? args)
     public IMessage CreateResponse(IMessage msg, String action, Int32 code, Object? value)
     {
         // 编码响应数据包，二进制优先
-        var (pk, str) = EncodeValue(value);
+        var pk = EncodeValue(value, out var str);
 
         if (Log != null && str.IsNullOrEmpty() && pk != null) str = $"[{pk?.Total}]";
         WriteLog("{0}[{2:X2}]=>{1}", action, str, msg is DefaultMessage dm ? dm.Sequence : 0);
@@ -129,9 +129,9 @@ public IMessage CreateResponse(IMessage msg, String action, Int32 code, Object?
         return rs;
     }
 
-    internal (Packet?, String) EncodeValue(Object? value)
+    internal Packet? EncodeValue(Object? value, out String str)
     {
-        var str = "";
+        str = "";
         Packet? pk = null;
 
         if (value != null)
@@ -160,6 +160,6 @@ public IMessage CreateResponse(IMessage msg, String action, Int32 code, Object?
             }
         }
 
-        return (pk, str);
+        return pk;
     }
 }
\ No newline at end of file
diff --git a/NewLife.Remoting/NewLife.Remoting.csproj b/NewLife.Remoting/NewLife.Remoting.csproj
index 2bf62e0..d8bf6fb 100644
--- a/NewLife.Remoting/NewLife.Remoting.csproj
+++ b/NewLife.Remoting/NewLife.Remoting.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net45;net461;netstandard2.0;netstandard2.1;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net40;net45;net461;netstandard2.0;netstandard2.1;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
     <AssemblyTitle>协议通信库</AssemblyTitle>
     <Description>提供高性能RPC客户端服务端，提供Http/WebSocket客户端服务端，提供应用级客户端</Description>
     <Company>新生命开发团队</Company>
@@ -44,15 +44,18 @@
     <Compile Remove="Models\TokenModel.cs" />
   </ItemGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0">
+  <ItemGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
   </ItemGroup>
 
-  <ItemGroup>
-    <PackageReference Include="NewLife.Core" Version="10.10.2024.601" />
+  <ItemGroup Condition="'$(TargetFramework)'!='net40'">
+    <PackageReference Include="NewLife.Core" Version="10.10.2024.0601" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)'=='net40'">
+    <PackageReference Include="NewLife.Core" Version="10.10.2024.0620-net40" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/NewLife.Remoting/WsClient.cs b/NewLife.Remoting/WsClient.cs
index 35990b3..4b4904e 100644
--- a/NewLife.Remoting/WsClient.cs
+++ b/NewLife.Remoting/WsClient.cs
@@ -1,4 +1,5 @@
-using System.Net.WebSockets;
+#if !NET40
+using System.Net.WebSockets;
 using NewLife.Collections;
 using NewLife.Data;
 using NewLife.Log;
@@ -442,4 +443,5 @@ private void DoWork(Object? state)
         WriteLog(msg);
     }
     #endregion
-}
\ No newline at end of file
+}
+#endif
\ No newline at end of file
diff --git a/XUnitTest/JsonEncoderTests.cs b/XUnitTest/JsonEncoderTests.cs
index 3d2d567..cc271dc 100644
--- a/XUnitTest/JsonEncoderTests.cs
+++ b/XUnitTest/JsonEncoderTests.cs
@@ -357,44 +357,44 @@ public void EncodeValue()
 
         {
             var value = new Packet(Rand.NextBytes(64));
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(value, pk);
             Assert.Empty(str);
         }
         {
             var value = Rand.NextBytes(64);
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(value.ToHex(), pk.ToHex(64));
             Assert.Empty(str);
         }
         {
             var value = new UserInfo2 { Name = "Stone", Age = 18 };
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(1 + value.Name.Length + 1, pk.Total);
             Assert.Empty(str);
         }
         {
             var value = DateTime.Now;
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(value.ToFullString(), pk.ToStr());
             Assert.Equal(value.ToFullString(), str);
         }
         {
             var value = 123.456d;
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(value.ToString(), pk.ToStr());
             Assert.Equal(value.ToString(), str);
         }
         {
             var value = new UserInfo { Name = "Stone", Age = 18 };
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             var json = value.ToJson();
             Assert.Equal(json, pk.ToStr());
             Assert.Equal(json, str);
         }
         {
             var value = new Exception("this is an error");
-            var (pk, str) = encoder.EncodeValue(value);
+            var pk = encoder.EncodeValue(value, out var str);
             Assert.Equal(value.Message, pk.ToStr());
             Assert.Equal(value.Message, str);
         }