Create A Global Object But Have The Events Within That Object Fire On A Separate Thread?
Oct 26, 2009
I have an object that is defined as a global variable based on custom class. Within that class I have an event that gets fired a certain intervals. These events are fired on the same thread as where the object is declared. How do I create a global object, but have the events within that object fire on a separate thread?
I have a TabControl object on my form with many tabs created in code (TabPages) and my problem is that the same objects that are in the initial TabPage needs to be in the other TabPages created in code, I have this done in code when the user clicks the 'New Tab' menu option, however the same code is used for any new tabs created. The problem created here is that I have an event against one of the objects that appear in the other TabPages, but because the same code is used to create any new tab pages, the event will only work on the newest tab page, if that makes sense? By the way these objects that appear on the other TabPages are properties at the top so events can be handled against them in the respective subroutine.
I am instantiating a form object in my code behind the dataset just to access some form level variables and to occasionally set a label in the navigator bar. Recently in the b2 Team version of VS2010 there are some strange errors thrown in the immediate window and then I'm tossed out of debug mode and back into the IDE. This code has been operating for some time in this project without this behavior. A team member has just reproduced the behavior in his development machine also.The error that starts the shutdown of the debug instance is this: Control accessed from a thread other than the thread it was created on.
I'm trying to build a language dictionary in VB NET in order to be able to have several languages in the application.This dictionary has a init method that loads from database the entire dictionary and stores it in memory.In the rest of the classes of the project, I added the reference and I can use directly the object without create a new instance because their methods are shared.
how i have to load the dictionary content in order that the rest of classes only accessing to Language.GetWord method obtains the properly record of the collection, same way as My.Settings class.When My.Settings is used from any class the values are loaded. I'm looking for the same effect.This is the code of the class:
Public Class LanguageProvider Private Shared CurrentLanguage As Collection Public Shared ReadOnly Property GetWord(ByVal Label As String)
[code]....
Function LoadLanguage must be called when the application loads, in order to access once to database. After that property GetWord must access to the collection with the words and return the result. The problem is that the instances are not the same and the dictionary is not loaded when a class uses it.
I have a strange question and a vb.net 2010 and wpf4 project. I have a label that, when clicked, captures the mouse (MyLabel.captureMouse) and follows it around the screen until the mouse clicks again, at which point the object and the mousecapture is released.
However, I still need the functionality of mouseenter for another object. How do I get these two things to work together?
After many searches i end up using this class for global keyboard hooking. Link: Global Hook post [code]My app is performing operations that take some seconds to complete (ftp upload small files on interval), and during this time the hook lovks the keyboard. This i dont want of course..I cant jump to Async FtpWebRequest right now because it needs many changes, so i thought that the solution would be to make the hoook live in another thread.A proposal is to move my time - consuming operations (upload) to another thread.Upon doing this i am facing other problems. Because the time consuming task (upload) is in a timer i would have to rewrite a big portion in order to synchronize the file->save with the file->upload and i dont mind the app locking for 3-4 secs. what i do mind is to loose the kayboard for 3-4 secs.
evrytime i add new controls to a form in vb.net the designer regenerates code and asks me to make corrections, so i have to keep on changing the object declarations to global using the 'global' keyword evertime it regenarates code,especialy dataset objects.how can i prevent this?
I am trying to write an VBA application in Excel 2010 using "Microsoft Soap Toolkit 3.0" on 64 bit Windows 7 to consume an web service. But i got an error while initializing an object of SoapClient30.
I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
Under component services, a COM+ component is used by the company, right-clicking it and choosing 'Activation' tab will show the 'constructor string' that is used for DB server connection by all applications. How can I access it the simplest way possible?
I have a class library that contains a number of classes. I would like to dynamically create an instance of one of these classes, set its properties, and call a method.
Example:
Public Interface IExample Sub DoSomething() End Interface Public Class ExampleClass
[code]I actually change the filter's "branchType", but I want to be notified that FilterContacts has changed, not just one of its fields. Is it possible?
I have am using a Twitter streaming class library, and would like to update a listbox when a new tweet is posted. I have it all set up to the point where a message box will show when a tweet comes in, but when I try to insert this tweet into a listbox I get this error: The calling thread cannot access this object because a different thread owns it. I don't know what I need to do in order to insert this tweet.
I am developing an IT Asset Tracking application using VB 2005 and SQL Server 2005 Express edition. Will I need to create classes to represent objects such as Computers, Printers, Scanners/Faxes, Contracts, Purchase Orders etc or are there any other approaches.For example, if I am correct, I will have a class called Computer and its properties will include Make,Model,CPU,Hard Disk,Memory etc. Is this the right approach.
Computers can be split up into Desktop PC's, Servers and Notebooks. Would I have to create separate classes for these as well or would they be ok under the Computer class.Once I create an object from the class, how can I use the object to interact with the SQL db.I am a beginner to VB.NET 2005 therefore I am slowly getting to grips with OOP.
i want to have some web browsers which navigate wile the thread is running and my problem is that I want to use a web browser object from .net in a thread. when i put a webbrowser object in my form, called webbrowser1, i cant reach it in the thread's operation(start thread). when i type webbroeser1 in the thread it doesn't undrestand what webbrowser1 is.
Currently I'm creating a task that runs a hardware i/o loop for the duration of my program.i.e. it's a task that's created at the program's start and runs a loop that is only broken at the programs termination. Each loop cycle communicates via ethernet to hardware.depending on time outs each cycle takes 30-300 msec)I've noticed that if the loop runs with out any break that the program really slows down... to counter act that I placed a thread.sleep(x) in the loop
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj Inherits baseObj Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
What is the recommended way in VS.NET to have a global application handler object? Something that can load/verify/return user folders, settings, application specfic settings, manage the unhandled exceptions, etc. I would have a class that has most of the code, then subclass it for each application.
I can create one if I start as a module instead of a form. But then I lose some options such as NetworkAvailabilityChanged, etc. I define a "Public" object from within a form (I don't think so and don't feel this would be the right approach.)?can I "attach" an object to an existing global object store (such as "My."), etc.?
Once created, any object in my application should be able to reference methods/properties of this application object to get default folders, user values, etc. as necessary.
This is also posted in the database development forum. As I think the same problem could apply to things other than connections, I am posting it here also. I have created a custom class. All methods in this class, I want to interact with a single connection object.
Imports MySql.Data.MySqlClient Public Class clsRegTester Private cn As New MySqlConnection
I have a huge website (containing around 5000+) pages. There is a theme functionality in the website where user can choose different colors for their profile. Now i want to use the ASP.net theme feature and put different CSS (for different colors) in the theme folder and in Global.asax i want check the user theme and render appropriate link element with the css. But my problem is, i am not able to access the Page element for adding the link in the page. Here is my code
Dim page As System.Web.UI.Page = TryCast(System.Web.HttpContext.Current.Handler,System.Web.UI.Page) page.StyleSheetTheme = "Black"
But when i run this code I get a Null reference error.
P.s : My application is very huge so its not possible to have a master page or a base class and inherit it in every page.
I need a single, global OleDbConnection. One which will be available to use throughout my app/project. Another project like a custom UserControl? I should mention I'm not using TableAdapters, BindingNavigitor, etc. The datasource is not associated with my project. I communicate with the Db through code I write. I'm just a hack trying to ride with the big dogs while I develop an app for my job... We were/are in the stone-age!!!
I am attempting to create a new mobile app using VB in visual studio 2008. I select "File" "New Project". Select "Smart Device" in new project window. Select the "Smart Device Project" from templates. Select ".NET Framework 3.5". Select "OK" and get the dreaded "object reference not set to an instance of an object"
I want to create a game using visual basic 2010. I'm a specialist in VBA and Excel but not VB 2010.I want to display and hide a whole group of objects. In Acces I used for such cases the TabControl. For example in Tab1 the Game, in Tab2 the highscore and in Tab3 the options. Then I made it transparent, so that the Tabs (Buttons) are not visible, only the objects in Tab1 Tab2 and Tab3. With VBA I select the Tabs controlled by my own buttons (jpg). I tried the same in VB 2010. Without success.What can I do to switch between game, highscore and options without using popups. I want to display them at the same positions. So game objects and option objects should hide and highscore objects should be shown. And the other way round. Like the handling is with different layers in photoshop!
I have a number of UserControls that have the same event .
When I use an Object instead of UserControl, I can not use Addhandler.
Here is the simplest example of my problem: In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1 AddHandler obj.TextChanged, AddressOf text_changed_event I have to use this structure, because in a FOR loop I use some different UserControls as obj. All UserControls have the same event.
Is there a way to use this structure without error?
Maybe there is a way to define a new object that covers all my UserControls.
I have a number of UserControls that have the same event .When I use an Object instead of UserControl, I can not use Addhandler.Here is the simplest example of my problem:In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1 AddHandler obj.TextChanged, AddressOf text_changed_event I have to use this structure, because in a FOR loop I use some different UserControls as
I'm using a com object in my vb net application. I'd imported the com library and everything is fine.But the object does not raise events, None. I need to know if there is some way to achieve that it works.
In a reply to one of my posts, a user said I should create an event for Textbox1.TripleClick.So, I would need to create an event.My problem is, how do I create an event for a textbox so that the event shows up in the textbox events?