National Instruments 320685D-01 Using LoadExternalModule on Source Files (.c)

Chapter 7 Creating and Distributing Standalone Executables and DL Ls

LabWindows/CVI Programmer Reference Manual 7-18

National Instruments Corporation

current working directory, \windows, \windows\system, then the PATH environment

variable.

2. Look for a .dll file in the directory of the executable. The .dll file must have the same

base name as the file you passed to LoadExternalModule.

3. Otherwise, use the standard Windows DLL search algorithm.

If you maintain the DLL glue object module as a separate file from the executable, you must

pass LoadExternalModule a pathname to the DLL glue object module, and it uses the

following search method to find the DLL.

1. Look for a .pth file that is in the same directory as the DLL glue object module and that

has the same base name as the DLL glue object module. If the .pth file contains an

absolute path to the DLL, use it to find the DLL. If the .pth file contains a simple

filename, use the standard Windows DLL search algorithm.

2. Look for a .dll file that is in the same directory as the DLL glue object module and that

has the same base name as the DLL glue object module.

3. Otherwise, use the standard Windows DLL search algorithm.

Note Before searching for a .dll file, a standalone executable always looks for a

.pth file. Therefore, your choice of whether to use a .pth file when you develop

your application in the LabWindows/CVI environment does not restrict your

choice of whether to use to .pth file in the standalone application.

Using LoadExternalModule on Source Files (.c)

If you pass the name of a source file to LoadExternalModule, the source file must be in the

project. LabWindows/CVI automatically compiles the source file and links it into the

executable when you select Create Standalone Executable File or Create Dynamic Link

Library. For this reason you must pass a simple filename to LoadExternalModule. If you

use an external compiler, refer to the, Using LoadExternalModule on Files in the Project,

section earlier in this chapter.

If the source file is an instrument driver program that is not in the project and you link in

LabWindows/CVI, you have two alternatives:

• Add the instrument driver .c source to the project.

• Refer to one of the variables or functions it exports in one of your project files.

If the source file is an instrument program that is not in the project and you link in an external

compiler, you must create an object file and keep it separate from the executable.