a) If the function returns true OR false will utilising the 'Using/End Using connection' statement close the connection cleanly? b) Is the 'Return TRUE statement' suitable placed to allow an error to occur and be raised returning a value of FALSE?
Public function doSomething () as boolean
Using conn As New SqlConnection(My.Settings.SQLConn)
Try
[code].....
Is there a way to catch a database exception and then redirect to an error page? I have a data access class that I use to make a sql connection and then functions that call it to execute my SQL commands. My problem is that if my database is not available I cannot catch that error. Here is the code I am using in my class[code]...
View 3 RepliesI'm getting 'Catch' cannot catch type 'Object' because it is not 'System.Exception' or a class that inherits from 'System.Exception'. and 'Expression detected' Code underlined in blue: Catch obj1 As Object When (?)
Private Sub OpenJAMem()
Dim num3 As Integer
Try
[code]....
MVC3, VB.NET, using EF. I am working on coding up a simple function to handle checking for a valid MySQL connection. If the connection fails the test it will use the secondary server connection. This is required because our hosting provider does not provide failover or redundant MySQL servers. The problem is I tried to use a simple try catch method in the HomeController. This fails early because the Entity Framework is looking the connection that was set up when I set it up... Is there anyway to control that connection dynamically?
View 1 RepliesMy code below. Problem description in comments.
Public Class Form1
'My local IP (going to be set to 127.0.0.1)
Private LocalIP As System.Net.IPAddress
[code]....
I was searching the most effective and elegant way do to the follows:
My function can be called while Filename is valid, corrupted, not exist
The function will just deserialize an XML object.
The main possible results are:
OK
File doesn't exist
Error in XML file
If I write this way, the reader won't be closed in case of corrupted file. IF I write the reader.close() inside finally block, It gaves me a warning about using read before assigning it a value.
So, how can I solve this inside the sub?
Public Function DeSerializzaXML(ByVal FileName As String, ByRef tmpObj As Object, ByVal tmpClass As Type) As Boolean
Dim serializer As XmlSerializer
Dim reader As StreamReader
[CODE]...
So basically I have a ComboBox on a form, which I populated by adding custom object named "Category" and by setting the DisplayMember to the property "Name" of my object.On another form that can be opened at the same time, I can edit the name of theses "Category" objects. I raise an Event, "NameChanged" but how can I catch it on the form which contains the ComboBox? Even if the property "Name" of the object "Category" change, the display on the ComboBox doesn't autoupdate. So I need to catch the event, but I don't know how to do it.
View 1 RepliesI was wondering i have a try block setup but need to catch an object exists error so I can continue in my code and ignore that user because she/he exists already in another ou.Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. - "Sherlock holmes" "speak softly and carry a big stick" - theodore roosevelt. Fear leads to anger, anger leads to hate, hate leads to[url]...
View 4 RepliesSQL connection - I planned to create one sql connection object inside my own singleton class (say connectionmanager with Reference counting for 'SQL connection object' which is a member of the class) and open/close the connection whenever needed. As I like to give high importance for performance. And my application is a desktop based application accessing a remote database server (SQL server 2008), and will use only one connection string, 50 concurrent desktop users may access db server. Please advice.
As like many articles say if the answer is "Connection pooling is taken care by ado.net" - Does that mean that scope of connection pool is entire life of Application instance? Or is it in the scope of SQLConnection object?
I have a program in VB.Net that receives mails from Outlook, extracts attachments and inserts the attachments into a table through a query. I would like to put the query/queries in a Try/Catch block, but cannot do so as Outlook exceptions cannot be caught, and it gives me an error, and unless I put a very specific exception, I cannot catch it. Is there a workaround?
Edit:
Try
Catch ex As Exception
End Try
Exception is underlined and when I hover on it, it says: "Catch cannot catch type 'Microsoft.Office.Interop.Outlook.Exception' because it is not in 'System.Exception' or a class that inherits from 'System.Exception'". This is affecting all my other code which I'd like to put into a Try/Catch block.
The following code causes a "Warning" that Variable is used before value assigned.How do I restructure this Try/catch to eliminate error on the myreader.close command in the Catch part? Code appears to work fine but I dont like Warnings. [code]
View 8 Repliesi have problem when i click a ADD button, there is one null value in the textbox .. so the try catch statemnt is to catch that null value error but after that the catch is success but the button click never stop excute the statemnt till the end of the button event.
View 6 RepliesI have this scenario: in a Sub I have a Try...Catch statement.Within that Try..Catch I call another sub.In that 2nd sub is also a Try...Catch.(see below for example).Now if an exception occurs in the 2nd sub's Try...Catch, which Catch gets excecuted? The 2nd one, the 1st one or both?
Private Sub sub1()
Try
..do stuff[code].....
If I throw an exception from within a catch, does the finally (from the catch) still execute? i.e.
Try
..some code with an exception in it...
catch ex as Exception
throw new SpecialException("blah blah" & ex.Message, ex)
[code]....
I need to catch log4net exceptions (its own exceptions not app exceptions logged by it). I wish there's a way of doing it this way: [code] I have this code implemented and there's no errors in compilation but i force log4net to have an error (pointing to a non existing database in the config file) and nothing is threw.I've tried the listener aproach: [code] and it's writing the errors to log4net.txt, the forced ones i mean.This last aproach has a couple of drawbacks: it won't append every error to the file, if the error is the same it doesn't write it, i can't get the listener to write every error to that file, only one (I don't know how to fully configure the trace listener, it might be that). Thus it won't append the date and hour to every line wich is a necesity for me. Finally i can't give structure to it (xml). Even if the listener work i need to use the try/catch aproach, since i'm using ExceptionHandling from Enterprise library to log the errors in my app.
View 1 RepliesI have a simple scraper. It works on some websites, but on some there is this Error:
Quote:
IOException was unhandled Unable to read data from the transport connection: The connection was closed
It is occuring at "Dim htmlresults As String = Urlcontents.ReadToEnd()".
'Create the HttpWebRequest object
Dim req As HttpWebRequest = WebRequest.Create(URL)
'Set the timeout to 1 second (or 1,000 milliseconds)
req.Timeout = 10000
[code]....
I am using VB.NET 2005 to create a Windows forms application. I have a procedure named SendMail that creates an instance of Outlook.Application, to send an email from my application. I found the code on this forum, I think.The procedure works fine, but I can't use error handling with it.I call the procedure from a button click event. I put the procedure call in a try/catch block, and the application won't build, with the following error.
Error 68 'Catch' cannot catch type 'Microsoft.Office.Interop.Outlook.Exception' because it is not 'System.Exception' or a class that inherits from 'System.Exception'. C:datadevdmtiQTSQTSv7_1_20100212wQTSQTSReportsCriteria
pt_frmReportViewer.vb 43 21 QTS
Here is the code:
Sub SendMail(ByVal sFile As String)
' Create an Outlook application.
Dim oApp As Outlook._Application
[code]....
Given a connection object (or series of them), does anyone know of a way to backtrack and get the provider name? I'm trying to create a generic dataset generator that someone could load up with n DbCommand instances populate the dataset without requiring any further information.
Theoretically, as a command requires a connection object, that's all the information one should need to create this tool.Given that I'm populating tables in a dataset, I figured the simplest way would be using a DataAdapter. The only problem is that to generate a generic DataAdapter, I seem to have to go through the provider factory which requires a provider string - which I don't have.
Also, given that the provider for each command could potentially be different (i.e. commands across numerous databases), does anyone have any suggestions that would keep this simple?I'd like not to have to require the user to provide the provider string for each command object if I can avoid it. This way the user can just pass a param array of DbCommands and I can take it from there.
im making a class.vb which has a sql connection. The class.vb will be used by all forms/windows on the application. So whenever a form needs to access the database, it will call class.vb.
This is the code in class.vb:
Public Sub Openconn()
Dim myConnection As SqlConnection
Dim connstring As String = "Data Source=192.162;Initial Catalog=db1;User Id=sa;Password=1;"
[code]....
but it gives error: value of type sqlconnection cannot converted to array of Sqlconnection.I just want a method that's useful for opening the connection and that is also useful when asigning to a command object.
I'm creating a VB.NET 2010 application which is connected to an Access 2010 database. I've set up a connection using the inbuilt connection wizard. I want to pull data from the tables using ADO.NET objects such as the data adapter to create datasets. The data adapter in ADO needs the connection object. Can I pull this from app.config? Should I junk the inbuilt connection and create a new one with code alone? Help.Scott M Brush
View 1 RepliesI'm designing a web service in ASP.NET and VS2008, and am using typed datasets for retrieving table data. These work well and establish their own connections through their associated TableAdapter objects. Edit: I'm using VB, BTW!I am now attempting to run a custom SQL string using a DataAdapter and a Command object, however I need to reference a Connection object in order for the Command to work. What is the best way to handle this?hould I:a) Create a global connection object using Global.asax, retrieving the connection string from web.config? (I've been trying that one already, with not much success)b) Create a class-level connection object using the InitialiseComponent method, also retrieving the ConnectionString from web.config?c) Retrieve a Connection from one of the TableAdapters that I've already created in my typed DataSets?d) Something else I haven't thought of yet?
View 2 RepliesI'm trying to connect to an 2007 access database. It looks like my connection string is right but I get an error stating "Object reference not set to an instance of an object."
Me.conn.ConnectionString = ("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & Application.StartupPath & "\CDE Database.accdb")
My database is in the correct folder. in this case I'm debugging so I have it in my debug bin. I've even checked my application start up path to confirm that I have it in the correct folder. I also double checked my extention. For Microsoft office 2007 the extention is accdb. I've also checked the file name spelling and case etc and all matches.
I have conn set as
Private conn As OleDbConnection
Can I use two command object with one open connection in one procedure at VB.NET?
View 2 Replieswith VB.NET + MySQL i am having a connection object which is public public MYcnn as MySql.Data.MySqlClient.MySqlConnection when my main form opens MYcnn will open & will be available for all the procedures & functions. i never close this connection until the last form of the application closes (yes of course i compromise of some security + performance issues)
my problems is(1)when & how the garbage collector works to collect my connection object if my connection object remains open for > then certain time(2) how to offer or fix the time of my connection object availableness to garbage collector (3) i would like to write an event for the connection object closed event(i am explicitly declaring the connection object)
Explain what these do and how you would use them?
View 11 RepliesI have a form with many textboxes. When the user exit, I ask him if he wants to save it, and if so, I save all data into text (INI) file.I'm looking for best practices how to know if the user changed something with any of textboxes?I know I can use 'change' event for each textbox, and use some global boolean variable to catch it. But since I have dozens of textboxes,I'd like to know if there is any better way?
View 1 RepliesI am performing a simple exercise of opening an SQL Server database connection, pulling the first record of a table from a DataReader object, and then closing the object. However, I have noticed that theres bit of a delay, about 5 seconds or so, in closing the connection. However, the delay only occurs after the command object executes the specified query. I've worked in a setup like this before and don't remember there being such a long delay while closing the connection. [Code] The connection closes almost immediately. What gives? I have narrowed it down to the where the .ExecuteReader line that causes the delay in the connection close. Whats causing the delay and how do I resolve it?
View 2 Repliesam trying to catch the inner exception for the smtpclass with this code below, but it give another error saying the innerexception is not defined
Try
mail.To.Add(lstRecipients(i))
Try
[code].....
Hi, i have a regex code to get the time from a webbrowser but there is more than 1 time all in the same format.I need it to get the first time it catches, atm it gets the last time not the first?
Dim Regex As New Regex("d+:d+( [AP]M)")
Dim Matches As MatchCollection = Regex.Matches(WebBrowser1.DocumentText)
For Each Match As Match In Matches
TextBox1.Text = (Match.ToString)
Next
Is there a way to catch ALL errors of the program?
Purpose: The idea is to catch all the errors of the program, load errorform which basically just says "A Error Was Detected" (Which I have already designed). Then send a web request to a formmail.php file with the said error (which i have already done).
In short: I need a way to catch ALL errors, and get the error string that it gave.