%DLL_NETCALL

Call a DLL routine in .NET

WNSupported in Synergy .NET on Windows

value = %DLL_NETCALL(dll_handle, [convention], func_name[, arg_array])

Return value

value

The value of the DLL function as an integer data type. (^VAL)

Arguments

dll_handle

The handle of the DLL, as returned from %DLL_OPEN. (i)

convention

One of the following calling conventions: (n)

DLL_TYPE_C

Use C calling convention.

DLL_TYPE_FASTCALL

Use __fastcall calling convention.

DLL_TYPE_STDCALL

Use __stdcall calling convention.

DLL_TYPE_WINAPI

Use WINAPI calling convention.

func_name

The name of the function to be called within the DLL. (a)

arg_array

(optional) A dynamic array of objects ([#]@*) used to pass data types to the function in the DLL.

Discussion

Rather than using %DLL_NETCALL, we recommend that you use the DllImport attribute to call native code from a managed application. You can specify the DllImport attribute on a method to denote an external method call in a COM or Win32 DLL and set the parameter values as needed. See Attributes (.NET) for information on using an attribute. See the second example in Examples for a code sample that uses DllImport.

The %DLL_NETCALL function calls a subroutine or function in a DLL from Synergy .NET.

Before invoking %DLL_NETCALL, check the documentation for your DLL to find out how the function is declared, which data type the function will return, which calling convention to use, and which arguments are necessary. If you call a DLL subroutine with improper arguments, the result is undefined. The Declaring variables based on argument expected table and Declaring variables based on return value table provide additional information about the return value of the DLL function and the arguments expected by the DLL function.

To create the elements in arg_array, use code similar to the following:

Arg_array = new Object[3]
Arg_array[1] = (object)myavar
Arg_array[2] = (object)myint
Arg_array[3] = (object)^addr(myavar)

and so forth.

Examples

main
record
    producer    ,a6 ,'999'
    application ,a6 ,'RUN9'
    users       ,i4 ,0
    sys_err     ,i4 ,0
    dll_hdl     ,i4
    sts         ,i4
    argArray    ,[#]@*
proc
    dll_hdl = %dll_open('syncli_api.dll')
    if(dll_hdl > 0)
      begin
        argArray = new Object[4]
        argArray[1] = (object)producer
        argArray[2] = (object)application
        argArray[3] = (object)^addr(users)
        argArray[4] = (object)^addr(sys_err)
        sts = %dll_netcall(dll_hdl,, 'win_lm_stat', argArray)
        sts = %dll_close(dll_hdl)
      end
endmain 

The example below shows how to use the DllImport attribute to call a DLL in .NET. This is the preferred method.

import System;
import System.Runtime.InteropServices;
namespace test
class Example
    ; Use DllImport to import the SYNCLI_API win_lm_stat function.
    {DllImport("syncli_api.dll", CharSet = CharSet.Ansi)}
    public static method win_lm_stat, int
    in Producer, string
    in Application, string
    out byref user, int
    out byref sys_err, int
    proc
    endmethod
endclass
    main
        record
        producer ,a6 ,'999'
        application ,a6 ,'RUN9'
        users ,i4 ,0
        sys_err ,i4 ,0
    proc
        test.example.win_lm_stat(producer,application, users, sys_err)
    endmain
endnamespace