VS 2010 - What To Do When Network Connection Drops With FileSystemWatcher
Jul 15, 2011
I can't see anything in the method list that lets you know when a connection drops (and since it's constantly checking, it seems that could have been in there, to raise a flag when it can't find the connection anymore...no?). Is there a way to know if the network connection drops? Is there a way to reconnect it? Is it just a matter of turning EnableRaisingEvents() off and back on to re-establish the link to the network share?
View 6 Replies
ADVERTISEMENT
Mar 26, 2012
I am writing some code as part of a framework for opening a file.The file is of custom type and should not be opened by more than one instance of my application. To stop multiple file opening I use a filestream to create a lock file and then keep said filestream open. This seems to work in preventing another instance of my application from opening the file ( as it will fail in recreating the lock stream in the files open code ) but if the file is on a network share and the network drops then the original application also can not access the file any more.The code to get the lock stream is as follows:
Try
' We need to keep this stream alive to prevent other applications gaining access to the lock
mLockStream = New FileStream(mLockPath, FileMode.CreateNew, FileAccess.Write, FileShare.None)[code]....
In this I create the lock stream the first time round and then if another application tries to create it, it throws an exception and stops them from getting any further. This is kind of how it needs to work, unfortunately as I said, if this is done across a network and then the network connection is dropped for some reason then I can not delete the lock stream as I get an IOException telling me a process cannot access the file as it is open in another process ( which shouldn't be happening I don't think).
View 1 Replies
Sep 25, 2011
I have written a application that has a TCP client and server to connect to a PLC. The Client works perfectly but it looks like the server drops out all the time. What happens is when I first start the connection it will update without any problems but after about 1min of no transfer the PLC can no longer send data to the application. Neither system gives an error and the PLC shows that it is transmitting the data but nothing comes through on the application side of things. I have tried to put in heartbeat to see if that would stop the drop out but to no avail.[code]
View 10 Replies
Feb 7, 2011
I built a dwonloader program which download a file from the web. I would like to insert an error message that pop up whenever the program fail to download the file and/or when the computer gets disconnected from the internet while the program is downloading the file.
View 12 Replies
May 12, 2011
I have a USB 3G dongle from Orange which is like a dialup connection, rather than a wireless connection.
Is there anyway in vb.net to control this connection? So disconnect is and recconnect it etc?The reason for this is automatically getting a new ip address without manually disconnecting in network connections.
View 6 Replies
Nov 27, 2009
im creating a program that will connect to a database (not local).That database will be access by everyone of my officemate for our data storage.The problem is the sample for creating a database is it make use of lacol database which can only be access by single user.how connect to a database later on after my deploying my application.
Scenario1:
interface program created: DONE
User input interface created: DONE
Database created(but not yet connected to the actual application): DONE
Scenario 2:
Program Deployed :DONE
Scenario3:how can i connect to the Database i created with program i just publish/deployed?
something like that i have a command button then it will open a dialog to locate an existing database then connect to that database (ms access database or sql database created in - creating database sample).
View 1 Replies
Feb 25, 2009
I have created a VStudio app. and I am encountering a problem when I use it. When I have filled out the form and have clicked submit, I get the error:
'''''''''Network connection does not exist''''''''
But, the connection does exist and I have checked it by running the link in vb, in my computer and it works perfectly. What else could possibly bring back this error???
View 2 Replies
Apr 20, 2010
how can i reset my network connection using visual basic?i need to do something similair to
ipconfig/release
ipconfig/renew
but using vb2008
View 10 Replies
Mar 11, 2010
How can I connect to sql server via network by using vb.net.
View 2 Replies
Sep 4, 2011
I'm using FileSystemWatcher in an application.it monitors the files in a folder, then do some processing. I monitor FileCreate, Change, Rename, Delete event.the problem is: when I copy some images to that folder, it fired the create event, but the file is not actually ready, so, when I load the file in the event handler, it failed.how can deal with this correctly?
View 2 Replies
Nov 19, 2011
This is the work of one responder for the most part, and is not indicative of the quality of most of the posts.But you can judge that for yourself.
If you are writing a program that is used to monitor the status of your network, then this thread may not be of interest.
If you are an application programmer that uses network resources to accomplish your goal, i.e. you are using SMTP, FTP, HTTP, NNTP, NTP etc., and you think that you need to check for a connection first, then read on.Follow up to this.Before getting all geeky let's take a little detour...
Five days a week I get up, eat breakfast, check my email, forums, etc., take a shower, get dressed, and then drive to school.Many of you probably have a similar routine.What is interesting about that is not what we do, but what we dont do,because of our expectations and experience.Here is what I dont do.
I dont stick my finger in the electrical socket to see if there is electricity for the coffee maker and toaster.I dont fire up the command prompt and ping some host on the internet to see if I have connectivity.I dont check the battery, tires, water level, clutch fluid level, washer fluid level, etc.,before I drive off.
All of that is based on expectation and experience.So why would you write an application that pings the internet before it did something (SMTP, FTP, HTTP, NNTP, NTP etc)???? Is your experience or expectation that the network will be down?To illustrate and hopefully convince you that, like Oblio, it is pointless, create a new form with three buttons. In the following examples I use a WebRequest / WebResponse as my 'Something'.Here is what some think is a good approach, the classic ping-then-do, what I think you shouldn't do.[code]....What is wrong with this code is that all of the network IO is being done without a Try / Catch block.
View 1 Replies
Jun 28, 2011
code snippet to get active network card name, that is the network card currently connected to the internet in c# or vb.net?
View 5 Replies
Feb 10, 2009
It will apparently allow me to enable/disable my network connection programatically.I'm not sure how I should call it?I've tried several things such as:Network.SetConnectionState("Network Connections", "Local Area Connection 2", "1", "0", True)[code]
View 3 Replies
Jun 8, 2011
I have a problem when trying to detect the computers network connection status.
Here is the code I have used:
Dim IsAvalible As String = My.Computer.Network.IsAvailable
If IsAvalible = True Then Label1.Text = "Connected" Else <code>
<code>If IsAvalible = False Then</code> I <code>
Label1.Text = "Disconnected"</code></code>
End If [/ICODE] End If[/ICODE]
But for some even when the network is disconnected or the computers wifi is turned on I still get the result of "Connected". I think there something wrong with the code.
View 2 Replies
Dec 19, 2009
Now I know we can not do a system like the SQL of the...[code]He only opened the database, is there any way to open and use Access database login information for it?I am unfamiliar with this program , someone people can help me?Empty, You can be a example to me !!I just want a can connect to the network database (Access Database) VB programming
View 6 Replies
Nov 3, 2008
I am currently improving an existing handheld application, this app makes live calls to our network over the wireless connection, if the wireless connection is not established I am displaying a holding screen to the user, this screen rechecks connection every three seconds.I want to put a button on this screen that closes down the application if the user does not want to wait any longer. At the moment I am using the application.exit command, however it continues to finish the first original thread (i.e. trying to process the dataset) before actually closing the application, I am looking for a way to kill the application there and then!
View 2 Replies
Apr 2, 2010
I may be SOL on this but I thought I would give throw it out for possible solutions.I am writing a computer access control service tcontrol my kids' computer use. Plan on open sourcing it when I have it working. It is written in VB.Net and needs to work on XP through 7.I am running into all sorts of security and desktop access issues on Windows 7.The service needs to run as admin to execute the NetSh command to disable the network. But I cannot interact with the desktop from the service so I IPC to a UI to handle other stuff, but I still cannot detect from the service if the desktop is locked. Argghh!
View 1 Replies
Apr 18, 2005
I'm running into this problem when it comes to determining a network logged on username and i hope someone can help me out or atleast point me in the right direction.Situation:1 Windows 2003 server that is serving files through Active directory. No Dfs installed, just plain files sharing.1 or multiple clients that access the files, make modifications and creates or deletes files. For arguments sake let's say that the clients are Windows XP computer and the users are logged on to the local domain (AD).Currently available:When the client alters, creates or deletes a file i have a (VB.Net Windows Service) script that tells me that this is being done and stores a record in a database for this action being performed.Desire:I wan't to know the client's ip-address, computername or logged on username so that i can store this to. I have tried about 20 different scripts but all check the username on the server side and not the client. So now i either get back "SYSTEM" or "NTAUTHORITYSYSTEM" instead of the user's AD name.Below is the code i use to monitor the directory and or file changes.The "writeDBLog" is where i want to pass the username to write to the database.
[Code]...
View 6 Replies
Jun 29, 2009
I am using the code below to test whether the user is connected using either a wireless or LAN connection. i.e. that the cable is plugged in, or the wireless is switch off. The code works fine for this. However, if you can spot any potential problems with this or you know of a better way I would be interested to learn more.
[Code]...
View 6 Replies
Aug 23, 2011
I am working on a project using VS2010 SQL2008 and I saw an ODD behaviour , First let me tell you that the app runs without any problem in my developing pc (Windows Xp sp3 32bit)But when I was trying the application in another pc (Windows 7 32bit)I got this exception: A network-related or instance-specific error occured while establishing a connection to SQL server.The server was not found or was not accessible.Verfiy that the instance name is correct and that SQl server is configured to allow remote connections.
Now what is weird in this exception; Is when the application reaches the DataAdpater.Fill(dataset) line I got this exception but when the app reaches the DataAdpter.Insert(....) It runs without any problem .
And what is more weird is that I noticed that the dataset that is used in the previous insert procedure can later be filled with dataAdapter.Fill(...) procedure which it was giving me an exception before .
I tried these things as a solution:
1)Checked SQlBrowser running..
2)No aliases to Sql server at all to remove...
3)remote area connection--OK
4)TCP and UDP port 1433,1434 exception in firewall
5)Unistalled my only antivirus Norton
6)Added Tcp/IP ports in Sql protocols
7)My connection String is : onnectionString="Data Source=ALISQLEXPRESS;Initial Catalog=PALMSDATABASE;Integrated Security=True"
8)Also tried using Sql Server authentication (user Id and password)
what is the difference between fill and insert? My app. runs smoothly on the original pc ,What should I do?
View 13 Replies
Jan 19, 2011
I HOST MY ASP.NET WEBSITE ON WEBSERVER ..But after upload when i try to access my site ...
[URL]
Then following error occurs ....
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
(provider: SQL Network
Interfaces, error: 26 - Error Locating
Server/Instance Specified)
i have changed my connectionstring in web.config file and all webpages to :
<connectionStrings>
<remove name="ConnectionString"/>
<add name="ConnectionString" connectionString="Data Source=69.16.253.19,1433; Network Library=DBMSSOCN; Initial Catalog=database;
[code]....
...before publishing and uploading my website to webserver ...I m confused the problem is from my local computer or the webserver ....and how to fix this error ?
View 4 Replies
Sep 8, 2011
I have this code:
[Code]...
View 12 Replies
Nov 18, 2009
Error message receiving A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) The project is written in VB.Net 2008. Production server uses SQL 2008, Dev Server uses SQL 2000. The application has been built and published.
Prod Connection String: strCN = "server=SGMAGNCPQ03.;Initial Catalog=APO_Tax;Integrated Security=True"
Dev Connection String: strCN = "server=S04423711940995.;Initial Catalog=APO_Tax;Integrated Security=True"
The Problem: When I change the connect string from dev back to prod and try to run my app, I get the above error message. If I reboot everything works fine but if I switch the connect string from prod to dev and try to go back to prod, I'm back to the same problem.
View 2 Replies
Aug 18, 2009
Here is my idea so far: I have a bunch of computers connected in a local network. One of them is a MySQL server, one will have a vb.NET program wich will act as a "second server" and the rest will be different clients. What I want to do is that the "second server" will send out some kind of message or network package to some of the clients in the network, and they will execute a code based on what message it is, or what kind of package it is. I'll give you a simple example:
[Code]...
View 6 Replies
May 18, 2011
I have this app written in VB.Net with winforms that shows some stats and pictures on a bigscreen monitor.I also monitor the memory usage of sad app by using this. Process.WorkingSet64
I know windows does not always report the correct usage but I just wanted to know if I didn't have any little memory leaks which I had but are solved now. But the first week the memory usage was around 100MB and the second week the memory usage showed around 50MB.
So why did it all of a sudden drop while still running the exact same code?I can hardly imagine that the garbage collector kicked in this late since the app refreshes every 10 seconds and it has ample time in between those periods to do it's thing.Or perhaps there is just better way to get memory usage for a process that is more reliable.
View 1 Replies
Aug 2, 2010
I've been using some code which I found on the net, and have noticed that the first byte is never recieved. Annoyingly, this contains the MAC addresses, which is the bit I want. Below is the relevant snippits:
Public Sub [Start]()
If m_Socket Is Nothing Then
Try
[Code].....
View 5 Replies
Sep 7, 2011
When it comes to database connections what is the difference between closing a connection & disposing a connection? I'm hoping to gain a more technical understanding of what happens when each is called & the effect on the database.
View 5 Replies
Oct 2, 2010
I have 3 lists in my form.When 1 list is clicked, I want to drop the selection in the other 2 lists.
Private Sub lstPlaylist_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstPlaylist.SelectedIndexChanged
lstArtist.ClearSelected()[code]....
This is my current code. When I click on lstPlaylist, it drops the selection for all lists.
View 1 Replies
Jul 6, 2011
Are there any IP Address filters or masks available in Windows Forms as per following screenshot? A backslash shouldn't be allowed or it should be filtered somehow.
View 1 Replies
Nov 20, 2009
Several times while debugging a VB.Net program I have found that continuation lines are missing from a subroutine designed to handle an event. The continuation character "_" is there but the following line is missing
[Code]...
The first few times I figured I had made some editing error, but this has happened 3 times now, always in the same way (different subroutines but same place). As far as I can tell, no other continuation lines have changed. Is this a bug or some feature I have missed?
View 2 Replies
