VC: Dynamic Link Library

MFC

1. Create a DLL

1. Create an MFC dynamic link library. In section 4th, select the Regular DLL With MFC shared linked type, that is, the conventional DLL for creating a dynamic link With MFC, it can be used by Win32 and MFC applications.

2. Add a function. Add the following statement to the test. h file of the generated project:

Extern "C" void _ declspec (dllexport) print ();

The declaration statement of the function is added above, and then the function body is written in the. cpp file.

Extern "C" void _ declspec (dllexport) print ()

{

CString str = "DLL ";

AfxMessageBox (str );

}

The above code is added to the statement:

CTestApp theApp.

3. Compile and connect. Generate the DLL and LIB files in the debug folder of the current file.

Ii. Use DLL

1. Create a dialog box-based application. Add a button.

2. Click the response function of the button:

Hdll = LoadLibrary (".. \ Debug \ MFCDll. dll"); // import the dynamic link library

If (hdll)

{

Typedef void (* PROCTYPE )();

PROCTYPE myprint = (PROCTYPE) GetProcAddress (hdll, "print"); // obtain the function address

(* Myprint )();

}

FreeLibrary (hdll); // release the database

3. Copy the generated Dll file to the specified directory.

 

Win32

 

1. Create Win32 DLL

1. Create an empty Win32 dynamic link library project;

2. Add the C ++ source file.

3. Compile the function fun (int a, int B) in the code area );

Int fun (int a, int B)

{

Int num1 =;

Int num2 = B;

Int temp = 0;

If (a <B) {temp = a; a = B; B = temp ;}

While (B! = 0)/* use the rolling division until B is 0 */

{

Temp = a % B;

A = B;

B = temp;

}

Return num1 * num2/;

}

4. Add a header file.

Int fun (int a, int B );

5. Add the module definition file (. def ). Create a notepad file and change the suffix to. def.

The content is as follows:

; Test. def: Declares the module parameters for the DLL.

 

LIBRARY "Win32Dll"

DESCRIPTION 'test Windows Dynamic Link library'

 

EXPORTS

Fun; Explicit exports can go here

6. Add module files to the project. FileView panel --> right-click test files --> Add File ToProject...

7. Compile and connect.

Ii. Use Win32 DLL

1. Copy the generated DLL files, Lib files, and test. H files to the specified directory. And add: # include "test. h" to the. cpp file of the application"

2. implicitly load the Win32 Dll file. Select Project | Setting command, select the Link tag in the pop-up dialog box, and enter the file name of the Library file lib to be imported in the "Object/Library module" text box. Note the lib path.

 

Dynamic Link Library Loading

 

1. Implicit join
(1) "Project" | "Settings" command. The Project Setting dialog box is displayed.
(2) Link --> Objects/Library modules: add the Library template path.
(3) Place the DLL in the corresponding path.
2. Display connection:
(1) Call LoadLibrary ();
(2) Call GetProAddress ();
(3) Call FreeLibrary ();

 

Export data and functions in the dynamic link library

 

1. Create a module definition file: *. def

The content is as follows:

LIBRARY filename

DESCRIPTION description content

EXPORTS

Functionname

2. Use the keyword _ declspec (dllexport) to export members of functions, variables, classes, and classes.

For example, use _ declspec (dllexport) to export functions in the dynamic link library.

Int _ declspec (dllexport) _ cdecl functionname (int a, int B)

_ Declspec (dllexport) Export class member:

 

Class _ declspec (dllexport) MyCLASS

{

}