Dynamic library call problem!

jesson

When calling a .dll or .lib file, under what circumstances will both files be required? Under what circumstances is a lib file sufficient? What is the difference between using only .lib and .lib and .dll? ? A little confused

xietao405

dll is dynamically loaded

lib is a static library

zdl_22

1. Use only lib, only static calls.
2.lib, dll, dynamically call lib as the connection file.

Now generally use the lib, dll method, that is, use the dll method so that the program takes up less space and is easy to upgrade.

In addition, using a lib file to dynamically call a dll is just one method. You can use loadlibrary instead of a lib file.

2511718

1. The implicit call requires the LIB&DLL, and the explicit loading only requires the DLL and the function prototype.
2.In the case of static connection, only the lib file can be provided.

紫焰狼狼

The two upstairs summarized it very comprehensively.

holyfield9

Linking dynamic libraries into implicit and explicit

Implicit: header files containing exported function / C ++ class declarations are required
       Import library file .lib
       The actual DLL (.dll file)

Shown: Just use LoadLibrary / GetProcAddress / FreeLibrary

jerryzhh

When only dll is used, use function to load dll; generally use LIB&DLL, just add #pragma comment (lib, "connserverd.lib") to the header file for convenience.

2511718

Explicit test loading: #pragma comment (lib, "xxx.lib")
Implicit loading, VC 7X environment:
-Project
-Properties
-Linker
-Input
-Additional Dependencies: Type your xxx.lib

mystonelh

For static connection, as long as .lib, no dll
There is also no .lib and .dll at runtime

There are two ways for dynamic connection
1. When compiling, you need .lib and the corresponding header file that contains the function declaration; you don't need .lib at runtime, but use .dll
2. If the dll is used in the program according to the addressing mode, it is required that the function name should be declared in the .def file when the dll is created. In this way, the .lib and .h files are not needed
Examples of addressing modes
 LONG lResult;
   HINSTANCE hModule;
   // Create a new function pointer data type
   typedef LONG (MULTIPLY2LONGSPROC) (LONG, LONG);
   MULTIPLY2LONGSPROC * pfuncMultiply2Longs = 0;
    // Import the file DYNLINK1.DLL, the file should be in the same directory as the EXE file or in the WINDOWS\SYSTEM\directory
   VERIFY (hModule = :: LoadLibrary ("DYNLINK1.dll"));
   // Get the address of the function Multiply2Longs () in the DLL
   VERIFY (
      pfuncMultiply2Longs =
         (MULTIPLY2LONGSPROC *) :: GetProcAddress (
            (HMODULE) hModule, "Multiply2Longs")
   );

hmily2yy

Dynamic libraries are easy to upgrade, load on demand, and do not occupy memory (when not in use). Static libraries do not have the burden of loading at runtime, but they are added from the beginning.