UE4 call DLL

[for UE 4.25.3]

UE4 call dll Methods and standards c And c++ identical , The core code is as follows ：

// contain dll The header file 
#include "C:/Users/Documents/Unreal Projects/MyProject01/MyPlugins/IGaussDiffusion.h"
#include "C:/Users/Documents/Unreal Projects/MyProject01/MyPlugins/IFactor.h"

// Definition dll Function pointers in 
typedef void (* destroyGaussDiffusion)(IGaussDiffusion* );
typedef void (*destroyFactors)(IFactor*);


// call dll Code segment 
FString filePath = FPaths::Combine(*FPaths::EnginePluginsDir(), TEXT("FangHua/"), 
		TEXT("GaussDiffusionDLL.dll")); // Concatenate the plugins folder and the DLL file.
	if (FPaths::FileExists(filePath)) {
		void* DLLHandle;
		DLLHandle = FPlatformProcess::GetDllHandle(*filePath); // Retrieve the DLL.
		if (DLLHandle != NULL) {
			// Release Gauss 
			destroyGaussDiffusion DLLdestroyGaussDiffusion = NULL; // Local DLL function pointer.
			FString procName = "freeGaussDiffusion"; // The exact name of the DLL function.
			DLLdestroyGaussDiffusion = (destroyGaussDiffusion)FPlatformProcess::GetDllExport(DLLHandle, *procName); // Export the DLL function.
			if (DLLdestroyGaussDiffusion != NULL) {
				DLLdestroyGaussDiffusion(gaussDiffusion);// Call the DLL function, with arguments corresponding to the signature and return type of the function.
			}
			// Release Mie theory 
			destroyFactors DLLdestroyFactors = NULL; // Local DLL function pointer.
			FString procName1 = "freeFactors"; // The exact name of the DLL function.
			DLLdestroyFactors = (destroyFactors)FPlatformProcess::GetDllExport(DLLHandle, *procName1); // Export the DLL function.
			if (DLLdestroyFactors != NULL) {
				DLLdestroyFactors(factor);// Call the DLL function, with arguments corresponding to the signature and return type of the function.
			}
		}
	}