Question

我在这里很难找到解决问题的方法。

我正在尝试将客户端API功能从C ++转换为VB.NET，我认为回调函数存在一些问题。

部分C ++代码：

typedef struct {

BYTE    m_bRemoteChannel;
BYTE    m_bSendMode;
BYTE    m_nImgFormat;  // =0 cif ; = 1 qcif
char    *m_sIPAddress;
char    *m_sUserName;
char    *m_sUserPassword;
BOOL    m_bUserCheck;
HWND    m_hShowVideo;

} CLIENT_VIDEOINFO，* PCLIENT_VIDEOINFO;

CPLAYER_API LONG __stdcall MP4_ClientStart（PCLIENT_VIDEOINFO pClientinfo，void（CALLBACK * ReadDataCallBack）（DWORD nPort，UCHAR * pPacketBuffer，DWORD nPacketSize））;

void CALLBACK ReadDataCallBack（DWORD nPort，UCHAR * pPacketBuffer，DWORD nPacketSize）

{ TRACE（ “％d \ n” 个，nPacketSize）; }

    .....
aa5.m_sUserName = "123";
aa5.m_sUserPassword="w";
aa5.m_bUserCheck = TRUE;

MP4_ClientSetTTL(64);
nn1 = MP4_ClientStart(&aa5,ReadDataCallBack);
if (nn1 == -1)
{
    MessageBox("error");
    return;
}

SDK说明：

MP4_ClientStart

此功能启动连接。通话的格式是：

LONG __stdcall MP4_ClientStart（PCLIENT_VIDEOINFO pClientinfo， void（* ReadDataCallBack）（DWORD nChannel，UCHAR * pPacketBuffer，DWORD nPacketSize））

参数 pClientinfo保存信息。这种联系。

nChannel持有卡片频道。

pPacketBuffer保存指向接收缓冲区的指针。

nPacketSize保存接收缓冲区的长度。

返回值如果函数成功，则返回值是此连接的上下文。如果函数失败，则返回值为-1。

说明

typedef struct {

BYTE m_bRemoteChannel;

BYTE m_bSendMode;

BYTE m_bImgFormat;

char * m_sIPAddress;

char * m_sUserName;

char * m_sUserPassword;

BOOL m_bUserCheck;

HWND m_hShowVideo;

} CLIENT_VIDEOINFO，* PCLIENT_VIDEOINFO;

m_bRemoteChannel保存客户端想要连接的频道。

m_bSendMode保持连接的网络模式。

m_bImgFormat：图像格式，0是主要频道视频，1是子频道视频

m_sIPAddress保存服务器的IP地址。

m_sUserName保存用户名。

m_sUserPassword保存用户的密码。

m_bUserCheck保存是否发送用户名和密码的值。

m_hShowVideo保留此视频窗口的句柄。

如果m_hShowVideo保持为NULL，则客户端只能在没有解码器的情况下进行记录。

如果m_bUserCheck为FALSE，我们将m_sUserName和m_sUserPassword发送为NULL，否则我们将发送每50个字节。

m_sIPAddress和m_sUserName的长度必须大于50个字节。

ReadDataCallBack：当库从服务器接收数据包时，会调用此回调。

我的VB.Net代码：

Imports System.Runtime.InteropServices

Public Class Form1

Const WM_USER = &H400

Public Structure CLIENT_VIDEOINFO
    Public m_bRemoteChannel As Byte
    Public m_bSendMode As Byte
    Public m_bImgFormat As Byte
    Public m_sIPAddress As String
    Public m_sUserName As String
    Public m_sUserPassword As String
    Public m_bUserCheck As Boolean
    Public m_hShowVideo As Long 'hWnd                      
End Structure


Public Declare Function MP4_ClientSetNetPort Lib "hikclient.dll" (ByVal dServerPort As Integer, ByVal dClientPort As Integer) As Boolean
Public Declare Function MP4_ClientStartup Lib "hikclient.dll" (ByVal nMessage As UInteger, ByVal hWnd As System.IntPtr) As Boolean


<DllImport("hikclient.dll")> Public Shared Function MP4_ClientStart(ByVal Clientinfo As CLIENT_VIDEOINFO, ByRef ReadDataCallBack As CALLBACKdel) As Long
End Function


Public Delegate Sub CALLBACKdel(ByVal nPort As Long, <MarshalAs(UnmanagedType.LPArray)> ByRef pPacketBuffer As Byte(), ByVal nPacketSize As Long)


Public Sub CALLBACK(ByVal nPort As Long, <MarshalAs(UnmanagedType.LPArray)> ByRef pPacketBuffer As Byte(), ByVal nPacketSize As Long)
End Sub


Public mydel As New CALLBACKdel(AddressOf CALLBACK)


Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    Dim Clientinfo As New CLIENT_VIDEOINFO()
    Clientinfo.m_bRemoteChannel = 0
    Clientinfo.m_bSendMode = 0
    Clientinfo.m_bImgFormat = 0
    Clientinfo.m_sIPAddress = "193.168.1.100"
    Clientinfo.m_sUserName = "1"
    Clientinfo.m_sUserPassword = "a"
    Clientinfo.m_bUserCheck = False
    Clientinfo.m_hShowVideo = Me.Handle 'Nothing


    MP4_ClientSetNetPort(850, 850)
    MP4_ClientStartup(WM_USER + 1, Me.Handle)

    MP4_ClientStart(Clientinfo, mydel)
End Sub

结束班

以下是代码的其他一些示例：

C＃

http://blog.csdn.net/nenith1981/archive/2007/09/17/1787692.aspx

VB

：//read.pudn.com/downloads70/sourcecode/graph/250633/MD%E5%AE%A2%E6%88%B7%E7%AB%AF%28VB%29/hikclient.bas__.htm < / p>

：//read.pudn.com/downloads70/sourcecode/graph/250633/MD%E5%AE%A2%E6%88%B7%E7%AB%AF%28VB%29/Form1.frm__.htm < / p>

的Delphi

：//read.pudn.com/downloads91/sourcecode/multimedia/streaming/349759/Delphi_client/Unit1.pas__.htm

Answer 1

这不是解决问题的完整解决方案，但我首先将StructLayoutAttribute（Sequential）添加到您的结构中。

Imports System.Runtime.InteropServices

<StructLayout(LayoutKind.Sequential)> _
Public Structure CLIENT_VIDEOINFO

c ++到vb.net，回调函数的问题

1 个答案: