在UE插件中使用动态链接库

一.在工程中创建和使用动态链接库的方法在，我的上一篇随笔中已经介绍过了

　　https://www.cnblogs.com/hanabc12345/p/17686826.html

二.使用之前的三个动态库文件，在插件中使用使用

优点是：动态链接库内容放入插件，可以跟工程分离，可以给任何工程使用

1.新建C++项目MyPlugin，新建一个空地图后面调试时用，打开插件，新建插件，选择第三方库模板，命名为M，然后更新项目，用C++打开，编译无问题

2.将myDll1.dll拷贝到...\MyPlugin\Plugins\M\Binaries\ThirdParty\MLibrary\Win64文件夹下

将myDll1.lib拷贝到...\MyPlugin\Plugins\M\Source\ThirdParty\MLibrary\x64\Release文件夹下

将TesLlib.h拷贝到...\MyPlugin\Plugins\M\Source\M文件夹下

3.更改CS文件，打开...\MyPlugin\Plugins\M\Source\ThirdParty\MLibrary文件夹下MLibrary.Build.cs修改代码

using System.IO;
using UnrealBuildTool;

public class MLibrary : ModuleRules
{
    public MLibrary(ReadOnlyTargetRules Target) : base(Target)
    {
        Type = ModuleType.External;

        if (Target.Platform == UnrealTargetPlatform.Win64)
        {
            // Add the import library
            PublicAdditionalLibraries.Add(Path.Combine(ModuleDirectory, "x64", "Release", "myDll1.lib"));

            // Delay-load the DLL, so we can load it from the right place first
            PublicDelayLoadDLLs.Add("myDll1.dll");

            // Ensure that the DLL is staged along with the executable
            RuntimeDependencies.Add("$(PluginDir)/Binaries/ThirdParty/MLibrary/Win64/myDll1.dll");
        }
        
    }
}

删除不需要的代码，将win64下对应的名称改为自己的。

 4.修改..\MyPlugin\Plugins\M\Source\M文件夹下M.Build.cs文件，增加一些内容，根据自己需要修改

        PublicDependencyModuleNames.AddRange(
            new string[]
            {
                "Core",
                "CoreUObject",
                "Engine",
                "MLibrary",
                "Projects"
                // ... add other public dependencies that you statically link with here ...
            }

5.修改M.h文件，（我觉得这步可以省略）

#pragma once

#include "Modules/ModuleManager.h"

class FMModule : public IModuleInterface
{
public:

    /** IModuleInterface implementation */
    virtual void StartupModule() override;
    virtual void ShutdownModule() override;
    void* ExampleLibraryHandle;

//private:
    /** Handle to the test dll we will load */
    
};

6.修改M.cpp文件，这步很重要

#include "M.h"
#include "Core.h"
#include "Modules/ModuleManager.h"
#include "Interfaces/IPluginManager.h"
#include "MLibrary/ExampleLibrary.h"
#include "M/TesLlib.h"

#define LOCTEXT_NAMESPACE "FMModule"

void FMModule::StartupModule()
{
    // This code will execute after your module is loaded into memory; the exact timing is specified in the .uplugin file per-module

    // Get the base directory of this plugin
    FString BaseDir = IPluginManager::Get().FindPlugin("M")->GetBaseDir();

    // Add on the relative location of the third party dll and load it
    FString LibraryPath;
#if PLATFORM_WINDOWS
    LibraryPath = FPaths::Combine(*BaseDir, TEXT("Binaries/ThirdParty/MLibrary/Win64/myDll1.dll"));

#endif // PLATFORM_WINDOWS

    ExampleLibraryHandle = !LibraryPath.IsEmpty() ? FPlatformProcess::GetDllHandle(*LibraryPath) : nullptr;

    if (ExampleLibraryHandle)
    {
        // Call the test function in the third party library that opens a message box
        //ExampleLibraryFunction();

    }
    else
    {
        FMessageDialog::Open(EAppMsgType::Ok, LOCTEXT("ThirdPartyLibraryError", "Failed to load example third party library"));
    }
}

void FMModule::ShutdownModule()
{
    // This function may be called during shutdown to clean up your module.  For modules that support dynamic reloading,
    // we call this function before unloading the module.

    // Free the dll handle
    FPlatformProcess::FreeDllHandle(ExampleLibraryHandle);
    ExampleLibraryHandle = nullptr;
}

#undef LOCTEXT_NAMESPACE
    
IMPLEMENT_MODULE(FMModule, M)

7.然后更新编译，成功！后面在UE中新建C++类继承蓝图函数库

然后在.h文件中新建

public:
    UFUNCTION(BlueprintCallable,Category="My Library")
    static int BFL_Add(int a,int b);

在.cpp文件中新建

#include "MyBlueprintFunctionLibrary.h"
#include "M/TesLlib.h"

int UMyBlueprintFunctionLibrary::BFL_Add(int a, int b)
{
    TesLlib* testlib = new TesLlib();
    int result = testlib->Add(a, b);
    delete testlib;
    return result;
}

8.编译成功后，在UE之前新建的地图中打开关卡蓝图，写入下图内容，打印出正确结果，表明成功！

 三.参考文献

1.UE5.1保姆级创建第三方插件库使用DLL,以及踩坑笔记_ue 插件开发_烟水寻常的博客-CSDN博客