Hi,
I'm getting a casting error using the code below. The error on the web page (when you click the error icon) is:
Sys.WebForms.PageRequestManagerServerErrorExceptio n: Conversion from string "application.msword" to type "Long" is not valid.
It's to do with declaring the mimeout integer pointer to the "<MarshalAs(UnmanagedType.LPWStr)> ByRef ppwzMimeOut As String" value in the function call.
If I change mimeout declaration to: "Dim mimeout as string" and return that and comment out the other mimeout referenced code it returns "application/msword" correctly but obviously the rest of the function won't work because there is no pointer to the original referenced mimeout address.
Has anyone got any ideas of what I'm doing wrong?
Thanks,
Denise
Imports System.Security.Permissions
Public Declare Function FindMimeFromData Lib "urlmon.dll" (ByVal pBC As IntPtr, <MarshalAs(UnmanagedType.LPWStr)> ByVal pwzUrl As String, <MarshalAs(UnmanagedType.LPArray, ArraySubType:=UnmanagedType.I1, SizeParamIndex:=3)> ByVal pBuffer As Byte(), ByVal cbSize As Integer, <MarshalAs(UnmanagedType.LPWStr)> ByVal pwzMimeProposed As String, ByVal dwMimeFlags As Integer, <MarshalAs(UnmanagedType.LPWStr)> ByRef ppwzMimeOut As String, ByVal dwReserved As Integer) As Integer
Public Shared Function getMimeFromFile(ByVal file As String) As String
Dim mimeout As IntPtr
If Not System.IO.File.Exists(file) Then
Throw New FileNotFoundException(file + " not found")
End If
Dim MaxContent As Integer = CInt(New FileInfo(file).Length)
If MaxContent > 4096 Then
MaxContent = 4096
End If
Dim fs As New FileStream(file, FileMode.Open)
Dim buf(MaxContent) As Byte
fs.Read(buf, 0, MaxContent)
fs.Close()
Dim result As Integer = FindMimeFromData(IntPtr.Zero, file, buf, MaxContent, Nothing, 0, mimeout, 0)
If result <> 0 Then
'Throw Marshal.GetHRForExceptionresult)
End If
Dim mime As String = Marshal.PtrToStringUni(mimeout)
Marshal.FreeCoTaskMem(mimeout)
Return mime
End Function
Unsolved 
