CGO 之 Dll调用

// GoDll.cpp : 定义 DLL 应用程序的导出函数。
//

#include "stdafx.h"
#include <iostream>
#include <cstdint>

void  __stdcall void_R0()
{
std::cout << __FUNCTION__ << std::endl;
}

void  __stdcall void_R1(const char* name)
{
std::cout << __FUNCTION__ << " ----> " << name << std::endl;
}

void  __stdcall void_R2(const char*name ,char **outName)
{
std::string _name = "HintSoft 新浩艺-";
_name += name;
strcpy(*outName,_name.c_str());
}

uint8_t __stdcall uint8_R1(char** outJson)
{
*outJson = new char[256];
memset(*outJson,0,256);
strcpy(*outJson,"Hello -> 你被骗了，这里没有Json,只有中文");
return 1;
}

void __stdcall uint8_R1_free(char** outJson)
{
if(outJson == 0) return;

if(*outJson == 0) return;

delete [](*outJson);
*outJson = nullptr;
}

typedef void (*CallBackFunType)(const char * in);
void setCallBackFun(CallBackFunType func)
{
if(!func)
{
std::cout << __FUNCTION__ << "   NULL ptr" << std::endl;
}

func("hello CallBackFuncType  ---- setCallBackFun");
}

EXPORTS
void_R0						@1
void_R1						@2
void_R2						@3
uint8_R1					@4
uint8_R1_free				        @5
setCallBackFun				        @6

package main

import (
"fmt"
"syscall"
"unsafe"
)

/*
#include <stdio.h>   // 如果要调用C.free 一定要在些包含对应的头文件
#include <stdlib.h>

// 以下两种方式任选其一
void CallBackFun( char* in);
//void CallBackFun( char* in)
//{
//	printf("%s\r\n",in);
//}

*/
import "C"

// export 必须要
//export CallBackFun
func CallBackFun(in *C.char) {
fmt.Print(C.GoString(in))
}

func main() {
fmt.Println("---------------------------------------------------------------")

handle, err := syscall.LoadDLL("GoDll.dll")
if err != nil {
fmt.Println(err.Error())
return
}

fmt.Println(handle.Handle)
fmt.Println(handle.Name)

void_R0, err := handle.FindProc("void_R0")
if err != nil {
fmt.Println("void_R0 不存在", err.Error())
return
}

void_R1, err := handle.FindProc("void_R1")
if err != nil {
fmt.Println("void_R1 不存在", err.Error())
return
}

void_R2, err := handle.FindProc("void_R2")
if err != nil {
fmt.Println("void_R2 不存在", err.Error())
return
}

uint8_R1, err := handle.FindProc("uint8_R1")
if err != nil {
fmt.Println("uint8_R1 不存在", err.Error())
return
}

uint8_R1_free, err := handle.FindProc("uint8_R1_free")
if err != nil {
fmt.Println("uint8_R1_free 不存在", err.Error())
return
}

setCallBackFun, err := handle.FindProc("setCallBackFun")
if err != nil {
fmt.Println("setCallBackFun 不存在", err.Error())
return
}

fmt.Println("--------------------------函数加载成功-------------------------")
// -------------------------------------------------------------------------
fmt.Println("---- void_R0")
fmt.Println(void_R0.Addr())
void_R0.Call()
// -------------------------------------------------------------------------
fmt.Println("\r\n\r\n---- void_R1")
fmt.Println(void_R1.Addr())
name := C.CString("li_jian_xing")
void_R1.Call((uintptr)(unsafe.Pointer(name)))
C.free(unsafe.Pointer(name))
// -------------------------------------------------------------------------
// 创建数组，传入char** 取出C函数中的数据
fmt.Println("\r\n\r\n---- void_R2")
fmt.Println(void_R2.Addr())
arg := make([]C.char, 1024)
name = C.CString("li_jian_xing")
void_R2.Call((uintptr)(unsafe.Pointer(name)), (uintptr)(unsafe.Pointer((&arg))))
C.free(unsafe.Pointer(name))
fmt.Println(C.GoString(&arg[0]))
// -------------------------------------------------------------------------
// 传入char** 取出C函数分配的内存，处理完再释放
fmt.Println("\r\n\r\n---- uint8_R1")
fmt.Println(uint8_R1.Addr())
var argc *C.char
uint8_R1.Call((uintptr)(unsafe.Pointer(&argc)))
fmt.Println(C.GoString(argc))
uint8_R1_free.Call((uintptr)(unsafe.Pointer(&argc)))
// -------------------------------------------------------------------------
// 向dll 函数设定回调
fmt.Println("\r\n\r\n---- setCallBackFun")
fmt.Println(setCallBackFun.Addr())

setCallBackFun.Call((uintptr)(unsafe.Pointer(C.CallBackFun)))

handle.Release() // 释放dll 句柄

}