Unity Native Plugin C#和C++互相调用

news2024/11/18 7:45:22

官方链接

1.DLL的方式：

C++代码：编译成DLL，导入Unity

#pragma once
#include <map>
#include <string>

//导出宏定义
#define _DllExport _declspec(dllexport)

//函数指针
typedef void (*NativeCallback)(const char*);

extern "C"
{
	//注意这里字符串不能用C++的std::string，和C#的string不等价，等价的是char*,即字符数组
	_DllExport void RegisterNativeCallback(const char* functionName, NativeCallback callback);
	_DllExport void UpdateNative();
}

//缓存C#函数的地址
std::map<std::string, NativeCallback> _callbackMap;

//导出让C#调用，注册C#端的函数，注册后就可以在C++端调用C#的函数，本质就职把C#函数的地址给到C++，C++调用。
_DllExport void RegisterNativeCallback(const char* functionName, NativeCallback callback)
{
	_callbackMap[std::string(functionName)] = callback;
}

//导出让C#调用
_DllExport void UpdateNative()
{
	//调用C#端的函数，可以在Unity性能分析界面看到Native update,用此方法可以在Unity界面查看C++代码的耗时
	_callbackMap[std::string("BeginSample")]("Native update");
	_callbackMap[std::string("Log")]("Native Log");
	_callbackMap[std::string("EndSample")]("Native update");
}

C#代码：

using AOT;
using System;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.Profiling;

namespace Haha
{
    public class TestCPPLib : MonoBehaviour
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        delegate void NativeCallback(string args);

        [DllImport("CPPLib")]
        static extern void RegisterNativeCallback(string functionName, IntPtr callback);

        [DllImport("CPPLib")]
        static extern void UpdateNative();

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackLog(string args)
        {
            Debug.Log(args);
        }

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackBeginSample(string args)
        {
            Profiler.BeginSample(args);
        }

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackEndSample(string args)
        {
            Profiler.EndSample();
        }

        void Start()
        {
        	//调用C++函数，注册C#函数
            RegisterNativeCallback("Log", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackLog)));
            RegisterNativeCallback("BeginSample", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackBeginSample)));
            RegisterNativeCallback("EndSample", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackEndSample)));
        }

        private void Update()
        {
        	//调用C++函数
            UpdateNative();
        }
    }
}

2.还有一种是C++源码作为插件，只支持il2cpp。

C++代码：直接放到Unity的Assets目录下

C#源文件：区别只在导入时不写具体的文件名，写：__Internal即可，因为用IL2CPP 后端的方式，会把C++源文件放到工程内部一块编译。

using AOT;
using System;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.Profiling;

namespace Haha
{
    public class TestCPPLib : MonoBehaviour
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        delegate void NativeCallback(string args);
		
		//区别在这里：
        [DllImport("__Internal")]
        static extern void RegisterNativeCallback(string functionName, IntPtr callback);

        [DllImport("__Internal")]
        static extern void UpdateNative();

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackLog(string args)
        {
            Debug.Log(args);
        }

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackBeginSample(string args)
        {
            Profiler.BeginSample(args);
        }

        [MonoPInvokeCallback(typeof(NativeCallback))]
        static void CallbackEndSample(string args)
        {
            Profiler.EndSample();
        }

        void Start()
        {
            RegisterNativeCallback("Log", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackLog)));
            RegisterNativeCallback("BeginSample", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackBeginSample)));
            RegisterNativeCallback("EndSample", Marshal.GetFunctionPointerForDelegate(new NativeCallback(CallbackEndSample)));
        }

        private void Update()
        {
            UpdateNative();
        }
    }
}