Infinite While Loop To Check For A Change In Database
Oct 10, 2011
Following code is used in a .NET 2.0 windows service to continuously monitor a the table in the Database.[code]Seelctjob method will connect to SQL server 2005 database and executes the following Select query to see if there is a record with a particular status code.[code]This Select Query is executed continuously. If there is a record Start method will process further.I want to avoid executing the query continuoulsy. I tried using Sleep method and timer control. Thread.Sleep method stops the execution for sometime.[code]What is the best way of connecting to DB and monitoring a table at regular intervals of time without having much performance impact? When to use thread.sleep and a timer control and what is the difference between them?
As you all know, If the dataBase requires a numerical value then an error will occur when the user tries to insert the incorrect data type. With the code below after the user types in a value beside an int value type then it will go into an Loop through more than what is needed. How can I apply the same logic but allow the program not to check the 60 rows (I set the row size to 60). I want to break out of it if there are blanks ONLY if a row is blank and not for a black cell, because if the user leaves one cell blank then it would loop through the 'for each' for how many rows that they is. Initially there are 60 rows.
MIS For Each item As DataGridViewRow In dgvLaser.Rows If IsNumeric(item.Cells(3)) Then Exit For Else MessageBox.Show("Check Record Count. Numerical values only..!") End If Next
1) Diff b/w nothing & string in terms of variable declaration.
2)Erase keyword.I have never heard of such keyword in mine whole 1 + yrs of exp.
3) Diff b/w functions & properties? I say,Functions return a value,But propertiesare used to set or get the values. He say properties also return a value.
4)How can we use a class as a datasource?
5)Partial Class? hey frnds above question is for C++ na.Or there is also such class in VB.Net.
6)When the error stack overflow comes?
7) How we can we make indefinite loop , without uusing any variable declaration.
I made a game in VB .Net that uses tcp and sends messages back and forth.What is happening is, every so often, the message cannot be sent quickly enough, so then the TCPObj.connect() method goes into a loop, until it reaches the timeout and then spits out an error. Most of the time though, it never gets to the error, my application just freezes, and then comes back after TCPObj.connect() succeeds. How can I make the connect() method do application.doevents while it's trying to connect? Basically, I dont want it to freeze up my whole application. Since tcp.connect() is a .NET method, I can't go in and add application.doevents.
I am a student attempting to learn VB.NET on my own. Today I wanted to tackle the BackgroundWorker component. I found an excellent article online: How To Use a Background Worker. I successfully completed the walkthrough and even performed the "adventorous" part that dealt with working with controls updating across threads using delegates.Now I came to a part that I didn't understand how it was working. To summarize the following code, I have a delegate that has a Label and a String in its signature. I then have a subroutine that is called on the worker thread. Inside this subroutine the delegate is created and (I guess) ran again so that it is on the same (Main) thread. Please correct me if I'm wrong here.
Here is the method is performed on the worker thread: Private Sub My_BgWorker_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles My_BGWorker.DoWork
Code: p = -1 Try ListBox3.SelectedIndex = p Catch ex As Exception ListBox3.SelectedIndex = -1 p = ListBox3.SelectedIndex End Try Just cycles through my listbox without exiting the try. It keeps having an error causing the catch again.
I am making a program thats going to be an msn style popup for reminders. I made an infinite loop to activate the popup when the date = current date. However its stuck in the loop and I cant run other functions while the loop is running. How can I get the alert to go off while also running the program?
Public Class Form1 Structure List Dim Name As String Dim Day As Date Dim Hour As String Dim Min As String [Code] .....
While building out an interface for patient/client lookup, we have a pull from out FoxPro EMR creating the patient table and populating the lookup on the EU interface.
I am trying to use a Web Service to return Json for a Collection of Users from a Database Table. I'm only new to .NET (< 1 week experience), and I don't want to use the UpdatePanel for AJAX. I have tried using the JavaScriptSerializer as well as Json.NET to serialize. Both cases seem to spawn an Infinite Loop.[code]
I wanted to draw a chart on a picture box. So I create a form, put a picture box on it, and then in the code of Form_load, I put a handler to the paint event of the picture box. This seems to create an infinite loop, judging from the behavior of the form.
Whenever I try to create a new CD object I get a stack overflow. I want a parameter to be passed into mediaFactory so that it could be determined what type of media is created. Why I might be having problems with this when I do this "Dim media As CD = New CD()" Public MustInherit Class MediaFactory Inherits MediaContext Implements IMedia Public Sub New(ByVal typeId As Integer) [Code] .....
This code hangs in infinite loop. Any ideas why is that? Is that a bug in .NET? Can I do something about it?
Dim urlRegex As New Regex("((?:[a-z][w-]+:(?:/{1,3}|[a-z0-9%])|wwwd{0,3}[.]|ftp[.]|[a-z0-9.-]+[.][a-z]{2,4}/)(?:[^s()<>]+|(([^s()<>]+|(([^s()<>]+)))*))+(?:(([^s()<>]+|(([^s()<>]+)))*)|[^s`!()
Im working with and trying to run an infinite loop on a new thread which at some point takes action (e.g. make changes to Viewport3D). But no matter what I use:
- BeginInvoke
- Background Worker
- Timer
I run into problems. My porblems are:
[Code]....
I am doing all this in WPF.
How can I run the loop in the background and get it to affect the Viewport3D controls content without throwing an error or freezing up the application? A Viewpoirt3D is a control in WPF.
I am descending all the directories of my C drive to get a complete list of all extensions.When I get to: C:Windows.oldDocuments and SettingsAll UsersApplication Data
the program goes into a loop: C:Windows.oldDocuments and SettingsAll UsersApplication Data Application Data Application Data until the path exceeds maximum length (248 characters for the directory).
I am trying to create a program that the user enters the number of enrollments for 5 different campuses during two semesters. I just got started and here is what I have so far but when I run the program it is stuck in an infinite loop and will not go to the next function. I am not sure how to end the loop. Here is what I have so far:
Module Module1 Dim SIZE As Integer = 5 Dim campus() As String = {"Decatur Day", "Decatur Evening", "Huntsville Day", "Huntsville Evening", "Distance Learning"} Dim semester() As String = {"Fall 2010 semester", "Spring 2011 semester"} [Code] .....
So I'm getting annoyed with this ffriend of min that keeps on asking for code off me for a VB assignemnt. Now I'd like to give him some code, but not the right code, (play a joke on him...he...he..). So thats the reason I'd like to write a infinite loop program for Internet Explorer. Would such Visual Basic program be possible?
I'm not going to write anything epic, but probably just the event handler to a button that keeps uploading internet explorer on a infinite loop after clicking. I know morally, this is wrong. I would rather be an ass than a lazy bastard.
I'm not even sure what I need to know. None the less lets say I got a timer with an if event to check if said event is triggered then it fires off some code. The problem is if said event is triggered it keeps firing off the code and I only need to do it one time. Whilst letting the timer keep checking if event happened. I hope I worded that right and here is a rough translation in code. [Code] Is there a way to keep checking if an event happened and only fire off the code one time?
I need to be able to have a loop which checks records in the database and if it matches up then do something. I need to check that zone = currentZone and if it does then to submit my update query.
I am trying to create a program that the user enters the number of enrollments for 5 different campuses during two semesters. I just got started and here is what I have so far but when I run the program it is stuck in an infinite loop and will not go to the next function. I am not sure how to end the loop.
Here is what I have so far: Module Module1 Dim SIZE As Integer = 5 Dim campus() As String = {"Decatur Day", "Decatur Evening", "Huntsville Day", "Huntsville
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 am writing a program for a client that will allow them to disable and enable services. I have the services loading into a checkboxlist on a form. When the user clicks the "update" button I go through all items in the checkboxlist and see if they are checked or not. The code I have so far, and the code Im stuck with is:
I have a Form with a Group Box with a number of check boxes within it, each check box has a text box next to it for the user to enter a number. I wondered if it was possible to loop through the check boxes within the Group Box to find out which are selected and output the value in the associated textbox next each checkbox as it loops?
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.
