UE5 C++ 第三方动态库的使用

一. 首先要拷贝对应的 第三方库

bin里有dll动态库，include里有动态库需要的头文件。

二.在Target.cs里，进行设置

头文件前面的路径为公共路径

设置需要一起打包的三方库文件

三.加载这个库

FPlatformProcess::GetDllHandle将他解析为 任意类型，用void* 接受。

	//加载dll
	FString tmpDllPath = FPaths::GameSourceDir() + TEXT("LearnProject/BassSDK/bin/x64/bass.dll"); //解析这个库
	BassDllHandle = FPlatformProcess::GetDllHandle(*tmpDllPath);
	if (!BassDllHandle) return;

再用FPlatformProcess::GetDllExport.传入这个解析出来库的指针，和你要使用的函数名的TEXT类型，比如TEXT("BASS_Init")。返回也要进行指针转换，转换为对应的函数指针。没想到函数指针在这里居然被用到。

	//初始化bass
	BassInitTOFunc BassInitTO = (BassInitTOFunc)FPlatformProcess::GetDllExport(BassDllHandle, TEXT("BASS_Init")); //拿到这个库的某个函数（初始化）
	if (!BassInitTO) return;
	bool isBassInit = BassInitTO(-1, 44100, 0, NULL, 0);
	if (!isBassInit) return;

我们用函数指针BassInitTOFunc接住返回值。它的定义如下

typedef BOOL(*BassInitTOFunc)(int, DWORD, DWORD, HWND, const void*);

这里是给 函数指针起了 叫BassInitToFunc的别名。可以看这篇文章的第三部分

C语言指针进阶（一）——深入详解“函数指针”与“指针函数”-CSDN博客

四.来回用库里的函数达到播放音乐效果

#pragma once

#include "CoreMinimal.h"
#include "UObject/NoExportTypes.h"
#include "bass.h"
#include "DLLManager.generated.h"

/**
 * 
 */
 //音效
#define AUDIO_BASS_BGM				"DiscoFlow.wav"
typedef BOOL(*BassInitTOFunc)(int, DWORD, DWORD, HWND, const void*);
typedef HSTREAM(*BassCreateTOFunc)(BOOL, const void*, QWORD, QWORD, DWORD);
typedef BOOL(*BassPlayTOFunc)(DWORD, BOOL);

UCLASS()
class LEARNPROJECT_API UDLLManager : public UObject
{
	GENERATED_BODY()
public:
	void InitDLL();
	//BGM
	bool PlayBGMTO();
	void* BassDllHandle;//Bass dll
	HSTREAM BassBGM;
};

// Fill out your copyright notice in the Description page of Project Settings.


#include "DLLManager.h"

void UDLLManager::InitDLL()
{
	//加载dll
	FString tmpDllPath = FPaths::GameSourceDir() + TEXT("LearnProject/BassSDK/bin/x64/bass.dll"); //解析这个库
	BassDllHandle = FPlatformProcess::GetDllHandle(*tmpDllPath);
	if (!BassDllHandle) return;

	//初始化bass
	BassInitTOFunc BassInitTO = (BassInitTOFunc)FPlatformProcess::GetDllExport(BassDllHandle, TEXT("BASS_Init")); //拿到这个库的某个函数（初始化）
	if (!BassInitTO) return;
	bool isBassInit = BassInitTO(-1, 44100, 0, NULL, 0);
	if (!isBassInit) return;

	//创建bgm文件流
	BassCreateTOFunc BassCreateTO = (BassCreateTOFunc)FPlatformProcess::GetDllExport(BassDllHandle, TEXT("BASS_StreamCreateFile")); //拿到这个库的某个函数（加载流文件）
	if (BassCreateTO)
	{
		FString AudioFile = FPaths::GameSourceDir() + TEXT("LearnProject/BassSDK/Audios/") + AUDIO_BASS_BGM;
		BassBGM = BassCreateTO(FALSE, TCHAR_TO_UTF8(*AudioFile), 0, 0, BASS_SAMPLE_LOOP);
	}
}

bool UDLLManager::PlayBGMTO()
{
	if (!BassDllHandle) return false;

	BassPlayTOFunc BassPlayTO = (BassPlayTOFunc)FPlatformProcess::GetDllExport(BassDllHandle, TEXT("BASS_ChannelPlay"));  //拿到这个库的某个函数（单通道播放）
	if (BassPlayTO)
		return BassPlayTO(BassBGM, true);

	return false;
}

测试

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "MyActor.generated.h"

class UDLLManager;

UCLASS()
class LEARNPROJECT_API AMyActor : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	AMyActor();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;

	//音效管理
	UPROPERTY()
	UDLLManager* AudioManager;

};

// Fill out your copyright notice in the Description page of Project Settings.


#include "MyActor.h"
#include "DLLManager.h"

// Sets default values
AMyActor::AMyActor()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;

}

// Called when the game starts or when spawned
void AMyActor::BeginPlay()
{
	Super::BeginPlay();
	 AudioManager = NewObject<UDLLManager>(this);
	 if (AudioManager)
	 {
		 AudioManager->InitDLL();
		// AudioManager->InitAudioManager();
		 AudioManager->PlayBGMTO();
	 }
}

// Called every frame
void AMyActor::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}