I made program which connects sql database via WiFi network. I have timer wich every 10 minutes updates textbox information from database. If Network connection will be lose, i do not whant to get any error and after that lose data wich is in textbox, until sql database connection will not be. How can i check if connection exists and after that update data from database? Something like that:
Conn = New SqlConnection(ConnectionString)
Conn.Open() ' if connection is lost there gets error
If Conn.State = ConnectionState.Open Then ' But this does not works
After running the following sub (VS debugger), I try to detach the database in SSMS, but it shows the connection open still and won't let me detach. If I close program in debugger, the database shows no connections. I check the dataadapter's connection in the finally block and is shows closed. What gives
Private Function ClientMasterDBFiles(ByVal MasterClientDBConnection As String, ByVal DBName As String) As DataTable
i am using access database for my program. now i have connected to the database in MDI form of main exe, and ir also works, user can log in, it gets verified etc etc etc. now here is the problem, when i load a form from dll and try to use any sql query on that form, i get message, "database connection is not opened". so what i did was, i added the connect() (a function i designed to connect to database) in the load part of the dll's form, it made the trick, query's started to run, everything went fine, and when i reload the form i.e after closing the form, i load it again from MDI form, i get error, connection already open..
I have an VB.NET application. This Application is permanently resident in memory and minimized to the tray area because we use it very often. The problem comes in when we VPN into a client's site. These VPN connections trash all other network connections to and from our machines.Then every time my VB.NET application refreshes its database, errors start occurring, because the machine has lost connectivity to the SQL server, however, these are not at the connection level, but only when the reader attempts to read.
I am checking for connection.open, but because of the SQL connection pooling, I just get a previous connection that was valid before the network was cut. Is there anyway to check if an actual SQL connection is valid, prior to re-issuing a connection from the pool?[code]...
Class con1 Public Function ConnectToSql() As SqlConnection Dim conn As New SqlClient.SqlConnection conn = New SqlConnection("data source=" & Server & ";" & _
This is my problem.I have a field set up in MS Access to Boolean YES/NO, this field is populated when the user check a checkbox on a windows form. If the user check a checkbox, the value is written as checked in the data field (MS Access).The problem is when I search for the user information, I need the information from the Data base to populate(return) to the windows form. Example: If I enter a users phone number and the user data is present, the form gets populated with the information the user previously entered which was store in the database.Example: If the user selected checkbox1 and submits the form. When I search for the user info, the check box should check(populate) because the user had checked it on submit.Here is what I have done:
[code]...
I am getting the check value correctly in the database using a Boolean.Here is one of the errors I am getting. Unable to cast object of type
'System.Boolean' to type 'System.Windows.Forms.CheckBox.I am having trouble putting the codes in a code tag or block
My application is like this : i have to search my data from database with some check box and text box when user select check box specific function go on and then when user enters some range of value in textbox then the result will shown in data grid view after that i can print it by selecting data my vb.net code is as follow:
I'm writing a Silverlight 4 application and would like to check when opening the installed out of browser application, whether there is a valid internet connection (to then download some data from my website). I realise that I could put a try catch around a WebRequest but that seems a bit hacky to me.
EDIT: What I meant by valid internet connection is just connected to the internet
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.
I want to check the connection of server path eg[ URL] whether exists or notI tried this System.IO.Directory.Exists("http://localhost/MyProject/ ")but it always return false.So does anybody know how to check it?
I'm having a problem with some users, my vb tools always check at the splash screen a response from a server with a simple:
Dim MyResult as string = oWebclient.DownloadString("www.mydomain.com/page.php")
This actually works for most users but in some clients the firewalls I think they block this call or bypass or something like that, I found that after telling the user to turn off the firewall everything works ok, now I have some users that according to them they don't have a firewall or they already disable and still they have the problem.
You can see from the image the error message they receive, so my question is do you know any kind of free tool that I can send to the user to maybe log what program or whatever is blocking the program to connect?
I have a little problem with checking if a sql connection is good.
Attached here i have a simple vb.net program that should check if the sql connection to the sql server is good. If i just run it once it works very well. But if i use it in a timer and check the connection to the sql server every 10sec it will only tell me that the connection is good (V=0).
I have tested the code with turning of the sql server service.
Dim connect As String = "Server=192.168.1.2;Database=Test;User ID=sa;Password=12345;Trusted_Connection=False" Dim sqlconnection As New System.Data.SqlClient.SqlConnection(connect)
We want to developed services to sending fax which should check internet connection after every 10 sec and should be work on all windows operating system.
I cannot use any host like[URL]..to check internet connection because it increase network traffic.
hi there,first of i know nothing at all and my goal is to make a app for xp to check a database and check/patch a iso and then to burn the result to dvd-dl, basically like a app called abgx360 checks the database then like xbox backup creator burns the game, i'd like to make a app to do both, i'm going to college next year in september to learn programing c+ andf a few other things, but thats a longtime away.
I have a Boolean that writes to a data field. The data field(column) is set to YES/NO, if the user check a checkbox, the value is written as check in the data field.The problem is when I search for the user information, I need to get to form to the state it was in when the user submitted it.
Example: If the use select checkbox1 and submits the form. When I search the form, I need to make that particular check box check.
I have create a simple app in vb.net that receive data from a bluetooth device ( data are simple strings like "90123.9mm"). Is there a way to check if the device has closed the connection ?
I looking for a solution for how to check if a connection to a remote computer exist or not using vb.net.
I 'm writing a program which will request data from a remote sql server. I need to check if the connection to the remote server exist, before open the connection or run the the sql command.
I would like to a program I'm building on loading to check whether there is a internet connection and if there is to connect to a ftp site and copy a file from there to a specified directory
For almost a week I am reading and trying to find a solution for checking connection state using a TCP Client (using socket class) In my scenario I have a TCP Client that is connected to a server (it is not controlled by me) and i want that from time to time to check the connection state, and reconnect if necessary.I have read a lot of information on the internet but i did not find a suitable solution.Briefly, these are the methods that i have found on the internet and try to implement.But unfortunatelly, i have found some scenarios where the TCP Server is closed and the TCP Client is still saying Connected 1.Example from MSDN
I am Using Visual Basic 2010. I want to check My Connection Status. Connected or not in Remote Server Connection (SQL Server 2008 R2). How To Check Connection Status..?
