I will connect with one database from several machines. In all machines they need to insert the data in single table. In that time: how to use multithreading and deadlock concepts? Using the MySQL database and also MS Access.
View 2 RepliesIn which situations we can do the multithreading and deadlock concepts. can give some examples
View 4 RepliesHow to run multiple funcations simultaneously using multithreading concept?
Actually i am making a software which has backend tool as MS ACCESS. it has 15000+ records in database and i need to display that records as my software loads..but it is much time consunable and sometimes it even goes out of time exception
If I have two Synclocks
synclock a
synclock b
end synclock
[code].....
I have a VB.NET GUI (VS2005) that calls into a VB6 DLL to query MSAccess 2003 databases using DAO 3.6. Yes, I know this is not an ideal scenario, but that's the way the current application is set up. Component Checker shows MDAC 2.8 SP1 is installed. This application usually runs for a long time on our customer's Windows XP SP3 system with no issues. Occasionally (read: after 11 minutes or 11 hours or days), we experience a hang in the application, such that it needs to be ended with task manager and restarted. According to crash dumps and one lucky capture within the debugger, all threads are waiting on objects/critical sections within ntdll.dll. My specific thread gets stuck there and comes from MSJet40.dll. In the crash dumps, most threads are stuck in NTWaitForSingleObject, RtlEnterCriticalSection, etc.
I've been troubleshooting this intermittent issue for months and am convinced this is a bug in MSJet40.dll. The version of the DLL is 4.0.9511 and I see there is a hotfix for 4.0.9514 on XP SP3 outlined in: =[URL] I would like to get this hotfix to see if it fixes the issue and speak with MS if it doesn't. I have crash dumps and procmon traces of these events. This sounds very similar to the dreaded "Jet Bug" that shows up on a Google, supposedly fixed for Windows 2003 Server SP1, but I see no mention of it on Windows XP SP3.
I was wondering if this is known / expected behavior. By design?Is it documented somewhere?
My 'real' code does need something to keep one thread from accessing a listview while another is busy clearing and refreshing the Items collection, so it's not as easy as omitting the synclock section in the example below (The SyncLock in my case is on the ListView).
This code, which can be pasted over a new empty form's user code class, deadlocks during the Invoke call. It doesn't reach the entry point of SetText (setting a brakpoint there, the deadlock occurs before the breakpoint is hit).[cod]e...
Quote:
System.Exception: Transaction (Process ID xx) was deadlocked on lock resources with another process and has been chosen as the deadlock victim.
I suspect this
Dim webc As New WebClient
webc.DownloadFile(remotexml, targetxml)
webc.Dispose()
Then i am using the targetxml right after that:
Dim xmldoc As New XmlDocument
xmldoc.Load(targetxml)
etc.
It seems that xml file is locked by the first process (WebClient).
I get the feeling I am still using asp type scripting techniques in the script below instead of proper asp.net scripting...
If this is true, how do I do the below the proper .net way?
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
[Code].....
I am reading file with text contents on it.sample dictionary.txt contents:
aa
abaca
abroad
apple
Snippet A:
Dim path as String = Server.MapPath("dictionary.txt");
Dim dictionary() as String = {}
Try
[code]....
Basically, I want to make sure that I can handle/prevent this error.Does Snippet B, solves the problem, if not is there other way so that I can prevent this error.BTW, this a web application and I am expecting multiple users.
Does VB Supports OOPS Concepts?
View 1 Repliesso i have a class called FOOTBALL,then another 3 classes/forms that inherit FOOTBALL, they control score (SCOREBOX), possession (POSSBOX), and quarter (QUARTERBOX).the FOOTBALL class has 4 variables, "score" (array of 2 ints), "teams" (array of 2 strings), "possession" (boolean), and "quarter" (int)after that i have another form called MAINBOX, which creates new instances of the 3 classes (SCOREBOX, POSSBOX, and QUARTERBOX) (like this: private scoring = new SCOREBOX)... however they all technically create their own FOOTBALL classes, so I cannot connect them.
View 4 RepliesThis is my first post as I don't like to ask questions without making sure I've exhausted all other means. I'm new to VB2008 and programming in general but I'm learning. I want to do several simple tasks. Doing each separately is easy but when I put them together I don't know what to do. For one thing to work all the code must be changed and everything else doesn't work.
1. Plot a graph of data from a DAQ. I can do this by using a Timer1_tick method and displaying the data on the linegraph as long as the timer is turned on. I've decided to stick with this method of acquisition. I want to acquire data for long periods of time (perhaps 3 hours) so a timer is pretty good. No problems here.
2. Apply a filter to remove noise from the plot dynamically as the data comes in so that I get a smooth curve instead of a jagged graph. I know I can do this with for loops if I'm using an array. But how do I do it since I'm using a timer? Here the problem begins.
3. Log every piece of the filtered data that the timer is getting to be exported to a CSV file. I learned how to do this with do loops but not with a timer or array. But I really need to use the timer this time.
4. Acquire statistics for the data like maximum value, minimum value, and average value dynamically as the data changes. I know how to do this with an array of data after all the data is acquired. But How do I do this with a timer while the data is still being collected?
5. Monitor the data coming in to execute an alarm (Or event, like stopping the acquisition) when the data coming in has plateaued and is constant (eg: The voltage I'm monitoring starts to become constant and becomes one constant value) - Ok I don't know anything about this.
6. Execute a mathematical operation on the data that has been acquired (post acquisition) like finding gradients and such. Basically this means "How do I now manipulate the data I have and where is this data stored?"
Here's my starting code that gathers data with a timer. How do I work from here?:
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As
System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Timer1.Enabled = False
[code]....
I want to do several simple tasks. Doing each separately is easy but when I put them together I don't know what to do. For one thing to work all the code must be changed and everything else doesn't work. I want to:
1. Plot a graph of data from a DAQ. I can do this by using a Timer1_tick method and displaying the data on the linegraph as long as the timer is turned on. I've decided to stick with this method of acquisition. I want to acquire data for long periods of time (perhaps 3 hours) so a timer is pretty good. No problems here.
2. Apply a filter to remove noise from the plot dynamically as the data comes in so that I get a smooth curve instead of a jagged graph. I know I can do this with for loops if I'm using an array. But how do I do it since I'm using a timer? Here the problem begins.
3. Log every piece of the filtered data that the timer is getting to be exported to a CSV file. I learned how to do this with do loops but not with a timer or array. But I really need to use the timer this time.
4. Acquire statistics for the data like maximum value, minimum value, and average value dynamically as the data changes. I know how to do this with an array of data after all the data is acquired. But How do I do this with a timer while the data is still being collected?
5. Monitor the data coming in to execute an alarm (Or event, like stopping the acquisition) when the data coming in has plateaued and is constant (eg: The voltage I'm monitoring starts to become constant and becomes one constant value) - Ok I don't know anything about this.
6. Execute a mathematical operation on the data that has been acquired (post acquisition) like finding gradients and such. Basically this means "How do I now manipulate the data I have and where is this data stored?"
7. Know any good free linegraphs with autoscaling?
Here's my starting code that gathers data with a timer. How do I work from here?:
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As
System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Timer1.Enabled = False
[Code].....
I m new to vb.net need some ideas about how to implement inheritance concepts in vb.net
View 1 RepliesOk, I've researched for hours about classes, creating classes, creating obj's of that class, but every tutorial I've seen has either talking about things that are different from what I'm doing, or they were written with the assumption that I understand X or Y. What I want seems simple enough but it's just not clicking. Here's what I'm trying to accomplish:
1. Player chooses from a list of characters
2. That character has specific attributes (power level, experience points, ect..)
3. When entering the combat page, the specific attributes are displayed in text boxes
with respective labels.
4. When battle is over, experience points are handed out and saved in player class.
It's probably laughable to some how simple this is but I'm really struggling with it.
I started programming 6 months ago, Visual Basic is kind of easy and I made lots of programs. Now I am confused now. I have a serious problems about DLL's but I didn't made them but I knew how to make use of them. Okay I have 2 programs and one was having a problem and other one has no problem, they have the same framework, same code, but they have problems.url...
View 12 RepliesRecently I decided it might be kind of neat to make a "fighting' game in Vb similar to a Mortal Kombat or Street fighter style game. If I understand everything it should be mostly collision detection and a lot of animation? What does everyone else think?
View 2 RepliesI am very new to VB.NET coding..My manager assigned me to write a Single Program that uses OOP concepts like Abstraction,Encapsulation,Inheritence and Polymorphism.As there is a time limit.
View 1 RepliesThis is my first post as I don't like to ask questions without making sure I've exhausted all other means. I'm new to VB2008 and programming in general but I'm learning. I want to do several simple tasks. Doing each separately is easy but when I put them together I don't know what to do. For one thing to work all the code must be changed and everything else doesn't work.
[Code]...
(i dunno what title that describes my question better) well, i'm new in this .NET box. i used by Vb6. and now i want to convert my vb6 app to .NET concept. well now i'm stuck with DataGridView, seems like this control is an "all in one" control and memory eater too. well what i want is to have 2 combobox column in datagridview. say as cboGridID and cboGridDesc
while i type in cboGridID in a row, the cboGridID is dropdowned and select the item which is by Autocomplete, while in cboGridID is active i want the cboGridDesc dropdowned too, and select the item by the same index in cboGridID. and vice versa if i type in cboGridDesc
A commercial application we are selling can display a User control written in VB.Net in the interface. I am writing a vertical strip that will display some of our ads to our customers. I would like to be able to control the message and the ads. My idea is to upload an XML file to our server, then have the Vb.Net add-in (user control) download the XML file to a temp location and display the contents as advertisement. 1. Is that a good way to do this? I am open to other suggestions. 2. Is there a way I could embed javascript inside user control? I want to be able to animate the text displayed if possible and I dont know how to do that in Vb.Net user control.
View 4 Repliesmake a user name and password in visual basic6.0,
View 3 RepliesI am replacing a VB6 application with a rewritten counterpart in VB.Net. In the VB6 app there was a 'control' application which presented a form to the user and allowed them to select a 'client' from a drop down list. Selecting a client caused the reading of an ini file which set client-specific parameters, including the program names of several dlls, which were also written in VB6 and registered on the subject machine.
For example, each 'client' had a different letter format, and the letter was written by the selected dll. This made everything late-bound, but there is only one user. Most of all, it made it convenient to continually update individual letters by updating only that dll, and dropping the dll on top of the old one. Thus the (clerical) user had only to be told to save this file to the usual folder. I could have compiled everything together in one exe, making my updates larger and more complex.
In re-doing this in VB.Net, how should I replace this sort of approach?
I could tie everything together in one big project (and compile it to an exe which is the large update I was avoiding). Should I just do that? If I continue with the approach of having my client-specific (.net) dlls compiled separately, does this make sense in the .Net world? How do I call them? Do they need to be registered as they were before? What's the right way to do this and still give me the flexibility I had?
[code].....
View 3 RepliesI want to compress and decompress folder and subfolder in vb.net in windows application.i am using vs2008.
View 10 RepliesI want to create a website like a forum to talk about new technology in my community.This website will useful for students also people in my country to improve their knowledge..So let share me some concepts or idea to research more about it.
View 4 RepliesHere are parts of my
Dim setting As My.MySettings
lvl As Integer
Dim xp As Integer
Dim xpt As Integer
[code]....
I have done the settings as type integer and set the values that I wanted but I get this error: A first chance exception of type 'System.NullReferenceException' occurred in Click Game concepts.exe
I am having difficulties grasping the concept / context of two dimensional arrays. For the assignment I am working on I am required to use radio buttons to allow a user to vote if they like or dislike an item from a combo box. The contents of the combo box have been populated through the IDE via tht item property.I understand how to set up my rows and columns, which will be, (0 to 4), (0 to 1). The trouble I am having is how to record and display the votes and have them correspond to the selected item from the combo box. Can anyone give me an example of how something like this works?
View 9 RepliesHas anyone implemented the mainframe concept of a Generation Data Group (GDG) in VB.
View 1 RepliesMy responsibility is to build a vb.net function that when a scanner scans an object, it would take the scanned string and call a stored procedure to get a row of data that match that scanned string and pass the data row to an application that would print out a label. below is my vb.net and sql server stored procedure script 1. Do I have to come up with a public class in order to store my row of data to pass it on to a different vb.net application that would take that data row and print out a label? 2. In my stored procedure, how would I return the founded data row to the vb.net function?
[code]...