How to pass in a value into AsyncCallback function

[Lenn]

Hi,

I am using .BeginInvoke to make an asynchronous call to a function, and
passing in a AsyncCallback, so client gets notification when method
completes, relevant code is provided below:

AsyncCallback callback = new AsyncCallback(t his.NotifyIt);
FtpClient ftpC = new FtpClient(FtpSe rver, FtpUserName, FtpPassword);
private void button4_Click_1 (object sender, System.EventArg s e)
{

ftpC.ChangeDir( remotePath);
ftpC.BeginGetFi leSize("test.tx t", callback);

}

//callback function
private void NotifyIt(IAsync Result result)
{
//close connection
ftpC.Close();
MessageBox.Show (result.IsCompl eted.ToString() );

}

//Async Delegate implementation
private delegate Int64 GetFileSizeCall back(String fileName);
public System.IAsyncRe sult BeginGetFileSiz e( String fileName,
System.AsyncCal lback callback )
{

GetFileSizeCall back ftpCallback = new GetFileSizeCall back(this.GetFi leSize);
return ftpCallback.Beg inInvoke(fileNa me, callback);

}

All works great but I can't figure out how to pass in a return value from
GetFileSize which is Int64 to the call back function. Can it be done at all,
or am I on the wrong page all together?

[Brendan Grant]

Looking at similar things last week I found:
http://msdn.microsoft.com/library/de...ngoverview.asp
to be an invaluable resource and even have a printed copy sitting next too me
right now.

When the callback has completed, you would simply capture the return value
from your call to ftpCallback.End Invoke() (which I do not see you using).

Brendan

"Lenn" wrote:

Hi,

I am using .BeginInvoke to make an asynchronous call to a function, and
passing in a AsyncCallback, so client gets notification when method
completes, relevant code is provided below:

AsyncCallback callback = new AsyncCallback(t his.NotifyIt);
FtpClient ftpC = new FtpClient(FtpSe rver, FtpUserName, FtpPassword);
private void button4_Click_1 (object sender, System.EventArg s e)
{

ftpC.ChangeDir( remotePath);
ftpC.BeginGetFi leSize("test.tx t", callback);

}

//callback function
private void NotifyIt(IAsync Result result)
{
//close connection
ftpC.Close();
MessageBox.Show (result.IsCompl eted.ToString() );

}

//Async Delegate implementation
private delegate Int64 GetFileSizeCall back(String fileName);
public System.IAsyncRe sult BeginGetFileSiz e( String fileName,
System.AsyncCal lback callback )
{

GetFileSizeCall back ftpCallback = new GetFileSizeCall back(this.GetFi leSize);
return ftpCallback.Beg inInvoke(fileNa me, callback);

}

All works great but I can't figure out how to pass in a return value from
GetFileSize which is Int64 to the call back function. Can it be done at all,
or am I on the wrong page all together?