How to call the function interface and callback function in C++ DLL in C#

1. Most of the basic data types in C# are the same as the basic data types of C++, so the conversion of basic data types is relatively simple. What needs to be paid attention to is the byte size. 2. What you need to pay attention to when converting C++ arrays and C# arrays is that you need to add a statement such as [MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)] to define an array with 10 array elements in C++. 3. The callback function interface of C++ needs to use the delegate function method in C#. In the callback function setting in C++, the address value is generally used, so the managed function needs to be displayed in C#. 4. For pointer arrays in C++, IntPtr in C# can be used; if it is just an address pointer, the reference type in C# can be used. Add ref

before the type for example: using System; using System.Collections.Generic; using System.Text; using System.Runtime.InteropServices;

namespace IPNBSVTD_CSharp { public delegate void StatusCallBack(IntPtr dwInstance, IntPtr wParam, IntPtr lParam) ; public delegate void VoiceCallBack(IntPtr dwInstance, byte ucDeviceIndex, IntPtr pInDataBuf, ref int pInDataLen, IntPtr pOutDataBuf, int nOutDataLen);

public enum VT_MESSAGE
{
    VT_MESSAGE_SET_DEVICE_INFO,
    VT_MESSAGE_UPDATE_DEVICE_INFO,
    VT_MESSAGE_UPDATE_MIXER_IN_CTRL,
    VT_MESSAGE_UPDATE_MIXER_OUT_CTRL,
    VT_MESSAGE_MISSED_CALLS,                // 未接来电};public enum VT_TASK_TYPE //终端状态{
    VT_TASK_TYPE_NULL,                //空闲(无任务)
    VT_TASK_TYPE_TO_MONITOR,        //发起监听
    VT_TASK_TYPE_BY_MONITOR,        //被监听
    VT_TASK_TYPE_TO_BROADCAST,        //发起采播
    VT_TASK_TYPE_BY_BROADCAST,        //接收采播
    VT_TASK_TYPE_TO_TALK,            //发起对讲
    VT_TASK_TYPE_BY_TALK,            //接收对讲
    VT_TASK_TYPE_MULTITALK,            //多方通话
    VT_TASK_TYPE_OFFLINETALK,       //离线对讲};public enum VT_TASK_STATE //终端任务状态        {
    VT_TASK_STATE_NULL,                // 无任务
    VT_TASK_STATE_STOP,                // 监听停止,对讲停止,广播停止
    VT_TASK_STATE_CONNECTING,        // 监听:连接中
    VT_TASK_STATE_CALLING,            // 对讲:呼叫中
    VT_TASK_STATE_BEGIN_BC_PROMPT,    // 广播:开始提示音
    VT_TASK_STATE_END_BC_PROMPT,    // 广播:结束提示音
    VT_TASK_STATE_ONGOING,            // 监听中,对讲中,广播中};public enum VT_TARGET_STATE // 目标状态{
    VT_TARGET_STATE_NULL = 0,            // 未知
    VT_TARGET_STATE_OFFLINE,            // 目标脱机
    VT_TARGET_STATE_STOP,                // 目标停止
    VT_TARGET_STATE_REJECT,                // 目标拒绝
    VT_TARGET_STATE_BUSY,                // 目标呼叫忙};

[StructLayout(LayoutKind.Sequential)]public struct VT_TASK_TARGET
{    public int nCount;                                // 监听,对讲,广播选择的目标数量
    public int nEditPos;                            // 当前正在编辑的位置
    public VT_TASK_TYPE xeTaskType;                            // 任务类型
    public VT_TASK_STATE xeTaskState;                        // 任务组的任务状态
    public VT_TARGET_STATE xeTargetState;                        // 对讲目标状态
    public bool bIsBegin;                            // 任务是否已开始(呼叫...)
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)]    public VT_TASK_STATE[] pxeTerState;    // 各终端的任务状态  VT_DEVICE_MAX_COUNT 6
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]    public ushort[] pwID;        // 终端ID(0:1号终端...)或分区号(1:分区1...) VT_BROADCAST_MAX_COUNT            128
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 128)]    public int[] piSerIdx;    // 各终端对应的服务器编号
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)]    public byte[] pucPanelNo;    // NAS-8521,呼叫到面板,终端对应的面板序号
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]    public char[] strFileName; // 文件广播时,当前广播的文件名
    public uint offlineTargetIP; //离线目标IP
    public ushort offlineTargetPort;  //离线目标端口};

[StructLayout(LayoutKind.Sequential)]public struct tagSERVER
{    public uint ipServer;                // 服务器IP (字节反序)
    public ushort wServerPort;            // 服务器接收端口 (字节反序)
    public bool bFixPort;                // 是否固定接收端口
    public ushort wHostPort;            // 本机接收端口 (字节反序)
    public bool bOnline;                // 是否联机
    public bool bIsPCM;                    // 是否是PCM/ADPCM压缩
    public bool bIs8K;                    // 是否是8K/22K采样
    public bool bIsMultiCast;            // 是否是组播/单播
    public bool bRecord;                // 是否录音
    public uint ipRecord;                // 录音IP
    public ushort wRecordPort;            // 录音端口};

[StructLayout(LayoutKind.Sequential)]public struct VT_DEVICE_INFO
{    public ushort wDeviceId;            // 设备编号(从0开始,显示时要加1)
    public uint ipHost;                    // 主机IP (字节反序)
    public bool bIsRegister;            // 是否注册
    public ushort dwVol;                // 当前输出音量
    public int iServerCount;            // 服务器的数量
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)]    public tagSERVER[] pxsServer;       // 服务器
    public int nTaskCount;                // 任务数量
    public int nCurTask;                // 当前任务(对应于xsTaskTarget的下标)
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 1)]    public VT_TASK_TARGET[] pxsTaskArray;        // 任务目标};/// 
/// 跨平台调用方法/// 
public class NativeMethod{    /// 

    /// 路径最大大小
    /// 
    public const int MAX_PATH = 260;

    [DllImport("IPNBSVTD.dll")]    public static extern void IPNBSVTD_DeleteDevice();

    [DllImport("IPNBSVTD.dll")]    public static extern byte IPNBSVTD_CreateDevice(byte ucCount);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_DeviceMute(ref bool pbMute, bool bIsAudioOut, bool bIsSet);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_DeviceVolume(ref int pdwVolume, bool bIsAudioOut, bool bIsSet);

    [DllImport("IPNBSVTD.dll")]    public static extern void IPNBSVTD_SetINIFilePath(byte ucDeviceIndex, string pINIFilePath);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_OpenServer(byte ucDeviceIndex, IntPtr hParentWnd, uint nMsg);    //[DllImport("IPNBSVTD.dll")]
    //public static extern bool IPNBSVTD_SetBCFromFile(byte ucDeviceIndex, bool bBCFromFile, bool bLoop,
    //    [MarshalAs(UnmanagedType.LPArray)]string[] pStrFile, short sFileCount);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetBCFromFileEx(byte ucDeviceIndex, bool bBCFromFile, bool bLoop, string strFile, bool bAdd);    public static void SetBCFromFile(byte ucDeviceIndex, bool bBCFromFile, bool bLoop, List files, short sFileCount)    {        for (int i = 0; i < files.Count; i++)
            IPNBSVTD_SetBCFromFileEx(ucDeviceIndex, bBCFromFile, bLoop, files[i], (i == 0) ? false : true);
    }

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetBCToTerm(byte ucDeviceIndex);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_GetCurTaskTarget(byte ucDeviceIndex, ref VT_TASK_TARGET pTaskTarget, int iTaskPos);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetCurTaskTarget(byte ucDeviceIndex, ref VT_TASK_TARGET pTaskTarget, int iTaskPos);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_TaskBegin(byte ucDeviceIndex, int iTaskPos);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_TaskEnd(byte ucDeviceIndex, int iTaskPos);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_GetDeviceInfo(byte ucDeviceIndex, ref VT_DEVICE_INFO pDeviceInfo);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_GetBCFileCurrent(byte ucDeviceIndex, StringBuilder strFile);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetStatusCallBack(byte ucDeviceIndex, StatusCallBack dwCallBack, IntPtr dwInstance);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetVoiceCallBack(byte ucDeviceIndex, VoiceCallBack dwCallBack, IntPtr dwInstance);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetFileBCNext(byte ucDeviceIndex);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetFileBCPause(byte ucDeviceIndex, bool bPause);        

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetFileBCPrevious(byte ucDeviceIndex);

    [DllImport("IPNBSVTD.dll")]    public static extern uint IPNBSVTD_GetBCFileCurrentPlayPos(byte ucDeviceIndex, ref uint pBcFileLen);

    [DllImport("IPNBSVTD.dll")]    public static extern bool IPNBSVTD_SetFileBCPlayListPos(byte ucDeviceIndex, byte ucPlayListPos);
}

}