c 函数作形参的例子, C#调用

最新推荐文章于 2023-10-15 16:36:59 发布

原创最新推荐文章于 2023-10-15 16:36:59 发布 · 681 阅读

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本文提供了一个C语言中函数作为参数传递的例子，并展示了如何在C#中调用C编译的DLL，包括设置回调函数进行通信。示例中包含C语言的函数声明、定义以及C#的委托定义、DLLImport声明和回调函数实现。

/* Type for main function. */
typedef int (*pj_main_func_ptr)(int argc, char *argv[]);

作为形参数

int pj_run_app(pj_main_func_ptr main_func, int argc, char *argv[],
unsigned flags);

static int main_func(int argc, char *argv[])
{
setup_socket_signal();

do {
app_restart = PJ_FALSE;

if (app_init(argc, argv) != PJ_SUCCESS)
return 1;

setup_signal_handler();

app_main();
app_destroy();

/* This is on purpose */
app_destroy();
} while (app_restart);

return 0;
}

//传实参数

int main(int argc, char *argv[])

return pj_run_app(&main_func, argc, argv, 0);
}

========================================================================================================

//header files

typedef void (* itemnotify)(int itemno,int value);

itemnotify m_itemnotify;

#ifdef __cplusplus
extern "C" {
#endif

#define _EXPORT_IMPORT_SERIALCOMM_ __declspec(dllexport)

_EXPORT_IMPORT_SERIALCOMM_ int Add(int a ,int b );

_EXPORT_IMPORT_SERIALCOMM_ void SetNotifyCallback( itemnotify notify );

_EXPORT_IMPORT_SERIALCOMM_ void Start( );

}

// 这是主 DLL 文件。

#include "stdafx.h"

#include "ExportTest.h"

#ifdef _MANAGED
#pragma managed(push, off)
#endif

BOOL APIENTRY DllMain( HMODULE hModule,
       DWORD ul_reason_for_call,
       LPVOID lpReserved
       )
{
return TRUE;
}

#ifdef _MANAGED
#pragma managed(pop)
#endif

int Add(int a ,int b )
{
return a+b;
}

void Start()
{
if (m_itemnotify==NULL)
return ;

int num=100;
while (num>0)
{
  int item_value= rand() ;
  m_itemnotify(num,item_value);
  Sleep(20);
  num--;
}
}

void SetNotifyCallback( itemnotify lpnotify )
{
m_itemnotify=lpnotify;
}

// C# 委托函数定义

[DllImport("ExportTest.dll")]
        public static extern int Add(int a, int b);

        [DllImport("ExportTest.dll")]
        public static extern void SetNotifyCallback(NotifyCallback lpNotifyCallback);

[DllImport("ExportTest.dll")]
public static extern void Start();

unsafe public delegate void NotifyCallback(int itemNo, int itemValue);

NotifyCallback m_NotifyCallback;

      private void button2_Click(object sender, EventArgs e)
        {
            m_NotifyCallback = new NotifyCallback(Notify);
            SetNotifyCallback(m_NotifyCallback);
            Start();
        }

        private void Notify(int itemNo, int itemValue)
        {
            ListViewItem item=listView1.Items.Add(itemNo.ToString());
            item.SubItems.Add(itemValue.ToString());

}