“地址”VB6到VB.NET

我有一些问题要将我的VB6项目转换为VB.NET

我不明白这个“AddressOf”函数应该如何在VB.NET中使用

我的VB6代码：

Declare Function MP4_ClientStart Lib "hikclient.dll" _
  (pClientinfo As CLIENT_VIDEOINFO,ByVal abab As Long) As Long

Public Sub ReadDataCallBack(ByVal nPort As Long,pPacketBuffer As Byte,_
  ByVal nPacketSize As Long)

  If Not bSaved_DVS Then
    bSaved_DVS = True
    HW_OpenStream hChannelHandle,pPacketBuffer,nPacketSize
  End If
    HW_InputData hChannelHandle,nPacketSize

End Sub

nn1 = MP4_ClientStart(clientinfo,AddressOf ReadDataCallBack)

您可能会看到此错误：

‘AddressOf’ expression cannot be
converted to ‘Long’ because ‘Long’ is
not a delegate type.

你可能想要做的是创建一个委托然后将adab的类型更改为该委托类型.将其添加到课程中：

Public Delegate Sub ReadDataCallBackDelegate(ByVal nPort As Long,_
  ByVal pPacketBuffer As Byte,ByVal nPacketSize As Long)

然后将您的P / Invoke声明更改为：

Declare Function MP4_ClientStart Lib "hikclient.dll" (ByVal pClientinfo As _
  CLIENT_VIDEOINFO,ByVal abab As ReadDataCallBackDelegate) As Long

不要删除/更改您的ReadDataCallBack Sub,您仍然需要它.

那时他编译应该很开心.但是,其他人提出的观点很重要. VB6中的整数和长整数的长度与VB.NET中的长度不同.因此在.NET中,只要在VB6中使用Long,就需要使用Integer.