IDE :: Partial Class Code Behind A Dataset Object / Is It Running In A Separate Thread
Jan 27, 2010
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've made an application which goes through a long procedure when a button is clicked. I don't want the user to think the program has frozen, so I'd like to add a marquee progress bar just to show that it's still running. However, if I simply add the progress bar and make it visible when the button is clicked, the bar will appear but freeze and wait for the procedure to finish before it starts scrolling.
I know this is due to both the procedure and the progress bar running on the same thread, but the tutorials I've seen on getting a process to run on another thread seem confusing. What is the simple way to make a progress bar run on a separate thread?
when trying to run a function in a separate thread, my reason for trying this is because since the application is only run on one thread, the GUI hangs when the function is called.[code]In this code, the Print screen Button is pressed and the function HookCallBack is called.The problem is that the function has variables that need to be passed and returned, and while searching, i found a website that had an answer for this, and it required the function to be put in a class, and then it could be run on a separate thread while still passing all the variables needed.url...But the code cannot be placed in a class without giving errors and it seems to me like i did something wrong. The code is meant to be used in a form and not a class.My question is, how would i go about running the HookCallBack Function in a Separate thread?
Here's the problem I am trying to solve. My program can export a file as a pdf. and other formats. I can open the file using process.start. My file doesnt have a good name so I am using a GUID as a name.
I'm working on a checksum tool, which loads all the files in a specific folder to a listview then, calculates the hash value of each file and save it to a text file.Ok, everything is working properly except for the calculation, when I start it on a separate the my UI freezes.[code]...
I have a textbox which is bounded to the typed dataset. If the user in the textbox &hit keydown, it should allow only numeric values with 2 decimal points and also it should not allow more than one "."(dot). I found many but all thats are using textbox event
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 extended an Entity Framework 4 entity class with a calculated property in a partial class. This member is not available on the client to which the entities are exposed via WCF RIA Services.when using C# appears to be changing the extension of the partial class file from .cs to .shared.cs. I tried this with my VB.Net solution (.vb to .shared.vb) and got a long list of errors. I believe what happened is that the partial class lost its association with the entity on the client - it inherited from object rather than EntityObject.
My best guess is that this is related to the way that VB.Net handles namespaces.Each project has a 'Root Namespace' which is prepended to anything that is defined within a code file. C# has a 'Default Namespace'which is the namespace into which new types are placed by default - via a namespace statement within the file.The partial class is probably having the client namespace prepended to it which puts it into a different namespace than the entity with which it is associated on the server.Is there any means of extending an entity in such a way that those extensions are available on the client via WCF RIA Services and VB.Net?
I am creating an IDE for a game script with similar functionality as the Visual Studio IDE (at least, some of it). The game script consist of code that looks visually a bit like C code. It uses braces to define the start and end of a 'class' and uses nested braces to define the start and end of an 'event' in a class.
What I want finally is to have two Comboboxes above the text editor, one that lists each Class and the other listing each Event. The comboboxes should also show the Class and Event that the caret is currently in, just like in Visual Studio.I have attached an example of such a script (you can open it with Notepad).However, here is a short example where you can also see how I "defined" classes and events:
class1 { event1 {
[code]....
As you can see, the classes are the 'names' of each block of code, defined by matching braces { }. The events are the names of each nested block of code, also defined by matching braces { } but inside a class. There is only one level of nesting.As you can also see, the layout can follow the standard C-style layout, or a slightly different layout (using the opening brace on the same line as the class/event name), or even a completely chaotic mess. As long as the braces match correctly, the code is valid.So in short, the large blocks are classes, while the nested blocks are events.
What I want to do, is parse an entire script, and store all the Classes (and eventually, also all the Events, but let's forget about them for now). I want to store the Class name, start position (defined as the start index of the name), end position (defined as the index of the closing brace) and the full text (defined as the text between start and end position, so including the name).
vb.net Public Class clsClass Private _Name As String
[code]....
The code works basically by finding every first opening brace (the opening brace of each CLASS, not event), and then loops through the class (using a brace counter to keep track of the nested braces) until it found the last closing brace. It then stores the name, start, end and fulltext in a new clsClass and adds it to the list to return.
I want to start a job in a new thread or using backgroundworker to do it but havent done that before and asking you wich way I should do it. My program has a datagridview with a list of files, one file per row. I want the user to be able to select a row and then press "Start download" to start a background job of the download. I want to get events back of the progress of the download.
I have a class clsDownload that handles everything and raises events back but how do I implement the backgroundworking?Should I use the System.ComponentModel.BackgroundWorker inside of the class or create some wrapper that handles this or use some other threading stuff?
Edit: I dont understand how to implement my download in the backgroundworker, any small example would be very nice. The example on msdn didnt get me far.I have a download class that has a StartDownload-function. Should I use the backgroundworker IN the class or in the caller? "feeling stupid"
I am having trouble accessing the main thread (my form) when calling thread is running in a class (or module). I have no problem to manipulate a data (in a thread) from a form, the textbox can be updated using delegate and invokerequired but it doesn't seem as easy when the thread that processes a variable is handled by a thread that is running in a class.
I have a Window Forms application (using clickonce installation, running on a terminal server) that occasionaly ends up with a thread that appears to be running in a tight loop. The user doesn't know this happens as the app continues to run as expected. Also I have determined that I can kill the problem thread without any apparent affect on the app.
I can use Process Explorer to find the instance of an app with the problem and can isolate the thread with the problem but haven't found any way to look into the thread to find anything that would help me determine what is causing the problem. Does anyone know of a way to some additional information about a thread, like maybe strings, that would help me zero in on the issue?
It's easy to do so in objective c but I do not know how to do so in vb.net update:I know about control.invoke. But control.invoke requires a control that may change from program to program. What would be the easier way?So yes program is winform. However I need a solution that does not depend on any specific control. If that's the case actually I do not need things to be run on main thread do I?
This is an IDE question for VB Express 2008. It might be a bug in the IDE, or maybe it's my fault somehow?
My main form is named FrmMain and in my application's properties I have set frmMain as my startup object. All of that seems like what a lot of coders do.
But while debugging I hit Ctrl-Break, as I have done for years, and I get an behavior in the IDE that I wasn't expecting. Upon doing so, I get the green background text and the green arrow indicating in a tooltip: "This is the next statement to execute when this thread returns from the current function." Even if I didn't have the designer document open, it automatically opens frmMain.Designer.vb in the editor and hihglights line in green. The line is of course: Partial Class frmMain which is line 2 of the file. (Yes, it's highlighting the second line of the designer-generated code.)
The thing is, frmMain seems to have fully loaded and it's my startup object. As far as I know there shouldn't be a "next statement to execute" at all because code should be idle. I don't want to see the Designer.vb document... I want to edit my own code. Even though my form is behaving just fine, could there somehow be an unfinished aspect of loading the form such that it is "not returning" from a function?
Edit: In response to a couple comments, I'm adding three screen shots:
Referencing an object (class) within a thread fails
I have an object ("a vb class") that needs to run on a separate thread and communicate with the U/I.
Even using sample code, I cannot get the object to run within a thread. I demonstrate this problem with two examples. The first calls a function within the form and it works perfectly. The second creates an object and performs the same calls, but fails.
example #1 [working] (Called within a form) Private Delegate Sub FuctionToBeRunInThreadDelegate Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
[Code]....
SUMMARY: When the thread creates the object, it appears that the object is not actually running inside of a thread or else form.InvokeRequired would be true. I have other more complex examples where this is strongly verified and evidenced, but I provided these two as a very simple demonstration of my problem.How can I have a thread "own" a series of individual objects so that the objects are run asynchronously and can independently report back to the U/I?
Not really asking for code, but I'm interested in knowing the basics of "thread performance".For example, you try to copy a bitmap in a pixel by pixel operation. (Is slow, but it is a nice example)
[code]...
This is, of course, very buggy and causes a lot of violation errors etc. But that doesn't matter right now. How come the multi-threading way is so much faster than the regular routine? Is the processor not running on full speed with the first code, and is it working harder on the second?I find it weird to see this type of "threading performance increase", as if every single thread gets their own piece of processor speed allocated like it is a new process
I'm reading data from a serial port, but the DataReceived event of SerialPort is handled on it's own thread. I want to handle this on the main thread, but simply declaring an event and raising it still results in it being processed on the SerialPort thread. I'm assuming I need to declare a delegate I can call, but I don't see how that would work.
For example, I want to call Sub HandleDataReceived() on the main thread from the DataReceived thread, having HandleDataReceived() run on the main thread. How would I do this?
I have a few forms that have a lot of really intensive updating along with a great deal of user interface (text boxes, button clicking etc) Is it possible to open a separate form as a separate UI thread from the start up form that called it to "show" or open or whatever the new method might be?
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.
My understanding is that thread.join will suspend the execution of code on the calling thread until the spawned thread finishes or is aborted...
With that in mind, I tried this:
For i = 1 to 50 threads = New Thread(AddressOf test) threads.IsBackground = True threads.SetApartmentState(ApartmentState.STA)
[CODE]...
However, the rest of the code runs when the loop finishes, not waiting for all the spawned threads to finish. Since the rest of the code needs the threads to finish (otherwise the rest will error).
I'm developing an application where depending on a textfile input i should update/insert some data into an Access database. Let;s say I'm updating the bookshelf of a book according to a textfile that goes like:
TEXTBOOK | BOOKSHELF 000000001 | 000000000A and so on
[Code]....
does that make any sense? What I'm trying to do is basicalle: check if a book exists, if yes, then attach to Dataset, change its Bookshelf to the one in the textfile and repeat until the file is completely read. The Bookshelf can or not exists, if it doesn't then it should be inserted, is it done automatically when I update the Dataset? Finally "Batch update" the whole Dataset.
I have a window service that Inherits System.ServiceProcess.ServiceBase. While running in debug mode (havent tested compiled), the thread does not see the current user credentials. I need the credentials so I can set up the WebProxy and I would prefer to use the account that service is running under instead of passing the user and pwd as a string.Can someone help me figure out why the code running in the class the inherits from ServiceBase does not have have the credentials of the logged in user?
When you create a new asp.net page in VS 2008 and choose code behind, it also creates the typical aspx.vb or aspx.cs file to go along with it.
At the top of those files, VS names the 'Partial Class' name the file structure and/or name of the aspx file.
The question: Is there a best practice for this? Can I just use a single class name for all the pages in my application or perhaps a single directory instead of having to give each one a unique name?
I would like to create a partial class for my form. I have a lot of events, and it gets messy, so I would like to break up sections into their own files. The problem: When I create a partial class of my form, say:
Partial Public Class Form1 End Class
Visual Studio decides I need another form for this partial class.
1. How do I create a partial class for a form?
2. If I cant do that, how can I break up all the events in my form into different files?
I am reading a book (ASP.NET 3.5 Enterprise Application Development with Visual Studio 2008: Problem Design Solution, WROX)The source code is written in C#, but I am a VB guy, so I am giving it a try. Somewhere in the 2nd chapter, there is a Linq to Sql file used that is generated by drag&dropping the DB tables from the Database Explorer. Because some tables have the same type of fields, there is an interface generated called IENTBaseEntity. The writer says its a good practice to implement this interface in another partial class (not the designer.vb file!). The reason for this is that when the LinqToSql file is modified (and regenerated) the changes wont be lost.
In C# this solution is easy to do (i think), but in VB.Net I get an error, because the concerning properties in the LinqToSql file do not append the 'Implement IENTBaseEntity.Property' line. When I press [Enter] after the interface implementation line, VS generates other properties like this
Partial Public Class ENTUserAccount Implements IENTBaseEntity '--->This line results in the error
' This is not the way it should be
Public Property InsertDate1() As Date Implements IENTBaseEntity.InsertDate Get End Get
Is there a way I can run a loop in a seperate thread and increment a progress bar each time the loop iterates? I am trying to run a loop that will take a long time to complete and I dont want the form to be completely crashed out while the loop is running. There are only two ways I can think to solve the problem. The first way is to run the loop on a timer. This is extremely slow. The other way is to use a thread.
