ftp callback example C#

[marfi95]

Hello all,

I've looked all over the internet and am not having much luck. I'm
trying to implement a callback out of a ftpgetfile method so I can give
my users an indication of the progress of their download since the
files are pretty big. I'm having problems setting up the callback
using the InternetSetStatusCallback method. I found a VB6 version, but
having all kinds of problems converting it to C#. I'm new to C#, so
I'm not all that familiar with event handlers, but I don't understand
how to use InternetSetStatusCallback or what it passes to the callback
method.

Does anyone have an example of this in C# or vb.net ?

Any help would be most appreciated.

Thanks,
Mark

 

[Dragon]

Hello Mark,

Take a look at this:

~
#Region "Declarations"
Friend Declare Function InternetSetStatusCallback Lib "wininet.dll"
( _
ByVal hInternet As IntPtr, _
ByVal lpfnInternetCallback As INTERNET_STATUS_CALLBACK _
) As Integer


Friend Delegate Sub INTERNET_STATUS_CALLBACK( _
ByVal hInternet As IntPtr, _
ByRef dwContext As Integer, _
ByVal dwInternetStatus As InternetStatus, _
ByRef lpvStatusInformation As InternetState, _
ByVal dwStatusInformationLength As Integer _
)

Friend Enum InternetStatus
ResolvingName = 10
NameResolved = 11
ConnectingToServer = 20
ConnectedToServer = 21
SendingRequest = 30
RequestSent = 31
ReceivingResponse = 40
ResponseReceived = 41
CtlResponseReceived = 42
Prefetch = 43
ClosingConnection = 50
ConnectionClosed = 51
HandleCreated = 60
HandleClosing = 70
RequestComplete = 100
Redirect = 110
IntermediateResponse = 120
StateChange = 200
End Enum

Friend Enum InternetState
Connected = &H1
Disconnected = &H2
DisconnectedByUser = &H10
Idle = &H100
Busy = &H200
End Enum
#End Region
Protected Overrides Sub OnClick(ByVal e As System.EventArgs)
MyBase.OnClick(e)
InternetSetStatusCallback(hInternet, AddressOf
InternetSetStatusCallback)
End Sub

Friend Sub InternetStatusCallback( _
ByVal hInternet As IntPtr, _
ByRef dwContext As Integer, _
ByVal dwInternetStatus As InternetStatus, _
ByRef lpvStatusInformation As InternetState, _
ByVal dwStatusInformationLength As Integer _
)
REM Handle callback
End Sub
~

It wasn't tested but should work.
Hope it will,
Roman

 

[marfi95]

Thanks for the reply. I'll give it a try.

Temporarily, what I did was change to code to not use a FTPGetFile, but
InternetReadFile instead since I have control over the buffer size.
My preference was to use FTPGetFile, so I'll give this is a shot.
Thanks again.