Question

ClientSocket can't connect

Asked by: WizardsHat

Hi all,

that's the situation:

My server program is open and listening.
My client program starts with a wrong hostname. Then I change the hostname at runtime to the correct one, and it immediately raises an ESocketError on API 'connect'. So it found the server socket, but couldn't connect for some reason.
(when I change the hostname to anther wrong hostname at runtime, it will take a few seconds and then raise an Exception with an Windows Socket Error on API 'ASyncLookup'.)
When I start the client program with the correct hostname, it DOES connect.
As far as I can see, my code is exactly the same.

WMNEWSERVER is called when ServerName is already the new host name.

procedure TFoClient.WMNEWSERVER (var Msg: TMsg);
begin
  if ClieSock.Active then
    ClieSock.Active := false;

  ClieSock.Host := ServerName;
  ClieSock.Port := 1300;
  ClieSock.Active := true;
end;

procedure TFoClient.FormCreate(Sender: TObject);
begin
...
  ClieSock.Host := ServerName;
  ClieSock.Port := 1300;
  ClieSock.Active := true;
end;


Another thing is that my ClientSocket never gets to TClientSocket.OnError but raises an exception FIRST. Maybe this is somehow related?


Thanks for any help,
Fran

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2003-01-13 at 18:39:57ID20455518
Tags

clientsocket

Topic

Delphi Programming

Participating Experts
1
Points
50
Comments
7

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. sending/recieving text in ClientSocket or ServerSocket
    How can i send/recieve text in ClientSocket or ServerSocket. can i have a sample source code for this
  2. Problem with ClientSocket connecting timeout
    I've got a chat derived application and when I try to connect between to dialed in machines (ping tim 400 ms) I get error 10049 (which I'm sure is some kind of time out). I have no problems when I use other socket programs (such as telnet.exe). I started replacing client so...
  3. ClientSocket, download html, disconnect
    Hi, I want to connect to a web server, download the html to be stored in memory or a text box. Then disconnect from the web server. An efficiant means of doing this would be nice. If i can store this in memory and quickly delete it, that's what I'm shooting for. Thank yo...
  4. irc ident using clientsocket
    hi, i'm trying to make a irc client using clientsocket and im having trouble with the ident. all i recieve is this: NOTICE AUTH :*** Looking up your hostname... NOTICE AUTH :*** Checking Ident NOTICE AUTH :*** Found your hostname NOTICE AUTH :*** No Ident response any ide...
  5. CGI and ClientSocket component
    I have created normal console CGI software that get string from HTML form. Then i have normal windows program in the same machine where the cgi is running. It has ServerSocket component that waits for a connection in specific port. When CGI software get the string it should o...
  6. Delphi 6 clientSocket ServerSocket Arranging clients
    In delphi 6, how could I make it so that when a CLientSocket connects to ServerSocket, the value of x in ServerSocket1.Socket.Connections[x] is incrmented by one on each connection to the server. Here is what I mean: procedure TForm1.ServerClientConnect(Sender: TObject; S...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: tyfingPosted on 2003-01-13 at 20:40:27ID: 7722752

use clientsocket's onconnecting function,

showmessage('Clientsocket1 is establishing connection';

this way, u can rule out/pin point if your CS is setting off or not. i

 

by: WizardsHatPosted on 2003-01-13 at 20:52:55ID: 7722809

Yes I did something similar and it goes to OnConnecting, but then the Exceptions comes directly afterwards.

 

by: tyfingPosted on 2003-01-13 at 23:24:47ID: 7723344

i did a few Client/Server apps b4, sometimes if the Client is run on the Server platform, it will cause error as the Outgoing port = Incoming. u can try using other PC to connect, see if the error exists.

 

by: WizardsHatPosted on 2003-01-13 at 23:45:41ID: 7723421

I now tried it with the server and client program on two different PCs with different IP addresses etc., but I still have the same problem.

 

by: WizardsHatPosted on 2003-01-16 at 18:37:10ID: 7745648

Well now, after two days, it works. I have no idea, I didn't change any code.

but thanks for your answers anyway, Tyfing!

 

by: tyfingPosted on 2003-01-22 at 19:23:11ID: 7788201

anyway, my Client/Server programme is working well but its running on Win95. After about 200-300 hrs of non-stop running, the errorboxes will pop up. I have about 3-4 Server apps running altogether on the PC and they all cause errors after running for long time on Win95, all the errors pop up around the same time. After a reboot, everything runs back to normal. Guess sometimes the OS is the problem.....now i did a simple programme to remind me to reboot after 100 hours of runtime. :) so far, no more errors. Hope this is of help to you.

 

by: WizardsHatPosted on 2003-02-08 at 20:41:59ID: 7911320

In case anyone is interested:

my problem was solved once I started using IP addresses instead of hostnames, e.g.

 ClieSock.Address := ServerAddress;
 ClieSock.Port := 1300;
 ClieSock.Active := true;

Now my Clientsocket connects instantly and not only after a program restart.

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...