Question

我正在尝试使用Sacha Barber提供的代码获取网络上所有电脑的所有计算机名称。原始文章的链接是here。代码最初是在C＃中，但我已将其转换为VB。当我从Visual Studio以调试模式运行程序时，它通常（并非所有时间）运行正常，但是当我部署程序时，它几乎从不运行。

在以下行失败：

Dim svrInfo As _SERVER_INFO_100 = DirectCast(Marshal.PtrToStructure(tmpBuffer, _
                                  GetType(_SERVER_INFO_100)), _SERVER_INFO_100)

我收到以下错误：

An unhandled exception of type 'System.ExecutionEngineException' occurred in mscorlib.dll
HResult=-2146233082

我知道它与内存分配有关，但我不知道如何避免这个错误。我尝试过使用Debug Diagnostics Tool 1.2，但即便如此，我也不确定要寻找什么。

Imports System.Runtime.InteropServices

Public Class NetworkInfo

Dim CurrentDomain As AppDomain = AppDomain.CurrentDomain

'import the NetServerEnum function from the netapi32.dll 
Private Declare Unicode Function NetServerEnum Lib "netapi32" _
(ByVal Servername As IntPtr, _
ByVal Level As Integer, _
ByRef bufptr As IntPtr, _
ByVal PrefMaxLen As Integer, _
ByRef entriesread As Integer, _
ByRef TotalEntries As Integer, _
ByVal serverType As Integer, _
ByVal Domain As IntPtr, _
ByVal ResumeHandle As IntPtr) As Integer

'import the NetApiBufferFree function from the netapi32.dll
Private Declare Unicode Function NetApiBufferFree Lib "netapi32.dll" _
(ByRef buffer As IntPtr) As UInteger

Public Structure _SERVER_INFO_100
    Friend sv100_platform_id As Integer
    <MarshalAs(UnmanagedType.LPWStr)> _
    Friend sv100_name As String
End Structure

Public Function GetNetworkComputers() As ArrayList

    Dim networkComputers As New ArrayList()
    Const MAX_PREFERRED_LENGTH As Integer = -1
    Dim SV_TYPE_WORKSTATION As Integer = 1
    Dim SV_TYPE_SERVER As Integer = 2
    Dim buffer As IntPtr = IntPtr.Zero
    Dim tmpBuffer As IntPtr = IntPtr.Zero
    Dim entriesRead As Integer = 0
    Dim totalEntries As Integer = 0
    Dim resHandle As Integer = 0


    Dim sizeofINFO As Integer = Marshal.SizeOf(GetType(_SERVER_INFO_100))

    Try
        Dim ret As Integer = NetServerEnum(Nothing, 100, buffer, MAX_PREFERRED_LENGTH,          entriesRead, totalEntries, _
                                           SV_TYPE_WORKSTATION Or SV_TYPE_SERVER, Nothing, resHandle)

        If ret = 0 Then
            For i As Integer = 0 To totalEntries
                tmpBuffer = New IntPtr(CType(buffer, Long) + (i * sizeofINFO))

                Dim svrInfo As _SERVER_INFO_100 = DirectCast(Marshal.PtrToStructure(tmpBuffer, _
                                                    GetType(_SERVER_INFO_100)), _SERVER_INFO_100)

                networkComputers.Add(svrInfo.sv100_name)

            Next
        End If
    Catch ex As Exception
        Console.WriteLine("Error getting network computers.")
    Finally
        NetApiBufferFree(buffer)
    End Try

    Return networkComputers
End Function

End Class

Marshal.PtrToStructure在mscorlib.dll中引发ExecutionEngineException

0 个答案: