diff --git a/ComputingServices/ComputingServices.vbproj b/ComputingServices/ComputingServices.vbproj
index 5da91ba..ca77106 100644
--- a/ComputingServices/ComputingServices.vbproj
+++ b/ComputingServices/ComputingServices.vbproj
@@ -231,6 +231,7 @@
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
     <Compile Include="Taskhost.d\Invoke\JSON\Argument.vb" />
+    <Compile Include="Taskhost.d\Invoke\RemoteCall.vb" />
     <Compile Include="Taskhost.d\Invoke\TaskInvoke.vb" />
     <Compile Include="Linq\LinqPool.vb" />
     <Compile Include="Linq\ILinq%28Of T%29.vb" />
diff --git a/ComputingServices/Taskhost.d/Extensions.vb b/ComputingServices/Taskhost.d/Extensions.vb
index 5fb7218..c7ff7c5 100644
--- a/ComputingServices/Taskhost.d/Extensions.vb
+++ b/ComputingServices/Taskhost.d/Extensions.vb
@@ -1,48 +1,49 @@
 #Region "Microsoft.VisualBasic::4c6028116bed86fe45bf6a4e74f0af36, ComputingServices\Taskhost.d\Extensions.vb"
 
-    ' Author:
-    ' 
-    '       asuka (amethyst.asuka@gcmodeller.org)
-    '       xie (genetics@smrucc.org)
-    '       xieguigang (xie.guigang@live.com)
-    ' 
-    ' Copyright (c) 2018 GPL3 Licensed
-    ' 
-    ' 
-    ' GNU GENERAL PUBLIC LICENSE (GPL3)
-    ' 
-    ' 
-    ' This program is free software: you can redistribute it and/or modify
-    ' it under the terms of the GNU General Public License as published by
-    ' the Free Software Foundation, either version 3 of the License, or
-    ' (at your option) any later version.
-    ' 
-    ' This program is distributed in the hope that it will be useful,
-    ' but WITHOUT ANY WARRANTY; without even the implied warranty of
-    ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    ' GNU General Public License for more details.
-    ' 
-    ' You should have received a copy of the GNU General Public License
-    ' along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-
-
-    ' /********************************************************************************/
-
-    ' Summaries:
-
-    '     Module Extensions
-    ' 
-    '         Properties: EnvironmentLocal, IPAddress, PublicShared
-    ' 
-    '         Constructor: (+1 Overloads) Sub New
-    '         Function: [AddressOf], AddressEquals, (+2 Overloads) Invoke
-    ' 
-    ' 
-    ' /********************************************************************************/
+' Author:
+' 
+'       asuka (amethyst.asuka@gcmodeller.org)
+'       xie (genetics@smrucc.org)
+'       xieguigang (xie.guigang@live.com)
+' 
+' Copyright (c) 2018 GPL3 Licensed
+' 
+' 
+' GNU GENERAL PUBLIC LICENSE (GPL3)
+' 
+' 
+' This program is free software: you can redistribute it and/or modify
+' it under the terms of the GNU General Public License as published by
+' the Free Software Foundation, either version 3 of the License, or
+' (at your option) any later version.
+' 
+' This program is distributed in the hope that it will be useful,
+' but WITHOUT ANY WARRANTY; without even the implied warranty of
+' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+' GNU General Public License for more details.
+' 
+' You should have received a copy of the GNU General Public License
+' along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+
+' /********************************************************************************/
+
+' Summaries:
+
+'     Module Extensions
+' 
+'         Properties: EnvironmentLocal, IPAddress, PublicShared
+' 
+'         Constructor: (+1 Overloads) Sub New
+'         Function: [AddressOf], AddressEquals, (+2 Overloads) Invoke
+' 
+' 
+' /********************************************************************************/
 
 #End Region
 
+Imports System.Reflection
 Imports System.Runtime.CompilerServices
 Imports Microsoft.VisualBasic.Net.Tcp
 
@@ -85,9 +86,7 @@ Namespace TaskHost
 #End If
         End Sub
 
-        Public ReadOnly Property PublicShared As System.Reflection.BindingFlags =
-            System.Reflection.BindingFlags.Public Or
-            System.Reflection.BindingFlags.Static
+        Public ReadOnly Property PublicShared As BindingFlags = BindingFlags.Public Or BindingFlags.Static
 
         ''' <summary>
         ''' 
@@ -107,7 +106,7 @@ Namespace TaskHost
 
         <Extension> Public Function Invoke(info As InvokeInfo, host As TaskRemote) As Object
             If host Is Nothing Then
-                Return TaskInvoke.TryInvoke(info)
+                Return RemoteCall.doCall(info)
             Else
                 Dim rtvl = host.Invoke(info)
                 Dim entry = info.GetMethod
diff --git a/ComputingServices/Taskhost.d/Invoke/RemoteCall.vb b/ComputingServices/Taskhost.d/Invoke/RemoteCall.vb
new file mode 100644
index 0000000..d330af0
--- /dev/null
+++ b/ComputingServices/Taskhost.d/Invoke/RemoteCall.vb
@@ -0,0 +1,46 @@
+Imports System.Reflection
+Imports System.Runtime.CompilerServices
+Imports Microsoft.VisualBasic.Serialization.JSON
+Imports sciBASIC.ComputingServices.TaskHost
+
+Module RemoteCall
+
+    ''' <summary>
+    ''' Invoke the function on the remote server.(远程服务器上面通过这个方法执行函数调用)
+    ''' </summary>
+    ''' <param name="params"></param>
+    ''' <returns></returns>
+    ''' 
+    <Extension>
+    Public Function Invoke(params As InvokeInfo) As Rtvl
+        Dim rtvl As Rtvl
+
+        Try
+            Dim value As Object = doCall(params)
+
+            rtvl = New Rtvl(value)
+        Catch ex As Exception
+            ex = New Exception(params.GetJson, ex)
+            rtvl = New Rtvl(ex)
+        End Try
+
+        Return rtvl
+    End Function
+
+    ''' <summary>
+    ''' A common function of invoke the method on the remote machine
+    ''' </summary>
+    ''' <param name="params">远程主机上面的函数指针</param>
+    ''' <returns></returns>
+    ''' 
+    <Extension>
+    Public Function doCall(params As InvokeInfo) As Object
+        Dim func As MethodInfo = params.GetMethod
+        Dim paramsValue As Object() = params.parameters _
+            .Select(Function(arg) arg.GetValue) _
+            .ToArray
+        Dim value As Object = func.Invoke(Nothing, paramsValue)
+
+        Return value
+    End Function
+End Module
diff --git a/ComputingServices/Taskhost.d/Invoke/TaskInvoke.vb b/ComputingServices/Taskhost.d/Invoke/TaskInvoke.vb
index 918e4ba..a5f6b88 100644
--- a/ComputingServices/Taskhost.d/Invoke/TaskInvoke.vb
+++ b/ComputingServices/Taskhost.d/Invoke/TaskInvoke.vb
@@ -82,48 +82,10 @@ Namespace TaskHost
 
         Public ReadOnly Property LinqProvider As LinqPool = New LinqPool
 
-        ''' <summary>
-        ''' Invoke the function on the remote server.(远程服务器上面通过这个方法执行函数调用)
-        ''' </summary>
-        ''' <param name="params"></param>
-        ''' <returns></returns>
-        Public Shared Function Invoke(params As InvokeInfo) As Rtvl
-            Dim rtvl As Rtvl
-
-            Try
-                Dim rtvlType As Type = Nothing
-                Dim value As Object = __invoke(params, rtvlType)
-                rtvl = New Rtvl(value, rtvlType)
-            Catch ex As Exception
-                ex = New Exception(params.GetJson, ex)
-                rtvl = New Rtvl(ex)
-            End Try
-
-            Return rtvl
-        End Function
-
-        ''' <summary>
-        ''' A common function of invoke the method on the remote machine
-        ''' </summary>
-        ''' <param name="params">远程主机上面的函数指针</param>
-        ''' <param name="value">value's <see cref="system.type"/></param>
-        ''' <returns></returns>
-        Private Shared Function __invoke(params As InvokeInfo, ByRef value As Type) As Object
-            Dim func As MethodInfo = params.GetMethod
-            Dim paramsValue As Object() = params.parameters.Select(Function(arg) arg.GetValue).ToArray
-            Dim x As Object = func.Invoke(Nothing, paramsValue)
-            value = func.ReturnType
-            Return x
-        End Function
-
-        Public Shared Function TryInvoke(info As InvokeInfo) As Object
-            Return __invoke(info, Nothing)
-        End Function
-
         <Protocol(TaskProtocols.Invoke)>
         Private Function Invoke(CA As Long, args As RequestStream, remote As System.Net.IPEndPoint) As RequestStream
             Dim params As InvokeInfo = JsonContract.LoadJSON(Of InvokeInfo)(args.GetUTF8String)
-            Dim value As Rtvl = Invoke(params)
+            Dim value As Rtvl = RemoteCall.Invoke(params)
             Return New RequestStream(value.GetJson)
         End Function
 
@@ -144,10 +106,9 @@ Namespace TaskHost
         <Protocol(TaskProtocols.InvokeLinq)>
         Private Function InvokeLinq(CA As Long, args As RequestStream, remote As System.Net.IPEndPoint) As RequestStream
             Dim params As InvokeInfo = JsonContract.LoadJSON(Of InvokeInfo)(args.GetUTF8String) ' 得到远程函数指针信息
-            Dim type As Type = Nothing
-            Dim value As Object = __invoke(params, type)
+            Dim value As Object = RemoteCall.doCall(params)
             Dim source As IEnumerable = DirectCast(value, IEnumerable)
-            Dim svr As String = LinqProvider.OpenQuery(source, type).GetJson   ' 返回数据源信息
+            Dim svr As String = LinqProvider.OpenQuery(source, value.GetType).GetJson   ' 返回数据源信息
             Return New RequestStream(svr)
         End Function