I have a backgroundworker that needs to contact a webservice. But when I run the background worker it just hangs forever at the line where I call a method of the webservice. I suspect this is because the webservice is defined at class level.
View 17 RepliesI am trying to run a backgroundworker to load data from my DAL (which is available in another class). I want to keep the UI available and not have the "locked up" feel while the object is loading.When I create a simple backgroundworker and Sleep the UI stays responsive and my controls can be updated after the sleep. As soon as I replace the sleep with a call to instantiate the object from my DAL, the UI locks up. Is there someway I can instantiate this object using the background worked and keep the UI responsive?
When the situation object is instantiated it could take several seconds for it to load completely, during this time is when the UI is locked up... It does eventually load just fine.
Private WithEvents backWork As New BackgroundWorker()
Dim sit As Situation
Private Sub btnLoad_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnLoad.Click
[code]....
I have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch)
Try
Me.cv_clsB = clsB
[code]....
If you run this code you will see that the 500 PictureBoxes that are added ( this is easier to show than adding pixels as a pixel is only a single point ) fall mainly on the diagonal.With regard the RANDOM class, why should this be like this when the bounds of the instances are? >>
p.Location = New Point(x.Next(0, Me.Width + 1
), y.Next(0, Me.Height + 1 ))
as in this code.>>
[code].....-2138214fdeb4
I am utilizing a centralized class object that needs to call another class object. The program itself will do something like the following
sFieldValue = CentralObject.ObjectHandler(1, TestFunction, "FunctionVar,FunctionVar2,FunctionVar3")
In the central object I have a function
Public
Function ObjectHandler(ByVal ObjectType
As
Integer,
[code]....
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?
Not sure how to do thisI have a hierarchy:
Deals at the top
Deals is a collection of Deal
Deal is a collecton of DealSlots
[code]....
I have a GUI class and a database class. I do something like:
Dim db as Database = getDatabaseObject(logTxtBox)
db.executeNonQuery("some update command here")
Within executeNonQuery I connect to the db, execute the command, disconnect and catch the exceptions. logTxtBox is the GUI txt box I want log messages written to. Currently it writes something like:
Connected to DB successfully
Executing "some update command here"
Excepetion: ........
Disconnecting from DB
I feel like this isn't the best structure for my logging. As soon I kick off executeNonQuery with a BackgroundWorker instead of with the main GUI thread I cannot access the GUI's logTxtBox from the BackgroundWorker's thread. Is there a better way to implement this kind of functionality?
I have a project that is structured as follows:
[Code]...
I want the module to execute first before anything else, and so I call module.main() from the MyApplication startup event. At about the point that program execution gets to the beginning of module-level declarations in the module, it also starts running though the class-level declarations in the thread classes, but long before the threads are declared or the threads are started in the module code. I can't figure out why it happens! Is there some way of supressing that until later (i.e when those classes are actually instantiated)?
I have a class that is used as follows:
Create an object
Run the RunIt method
The object runs some code and sometimes raises Event1 and sometimes Event2
I want to run that object using Background worker
Programming the app I wasn't sure of the code so I created the VS project shown below so I could make this post
Many questions:
Which routines in the code are run on the worker thread?
Is the object created on the worker thread?
And are its events run on the worker thread?
How to handle the Cancel. The way I did appears tp work except that
e.Cancelled does not return as true (Done is displayed).
And suppose the object didn't have events how would I handle Cancel?
Is there a better way to handle the basic problem?
I wish the code was shorter but wanted to be sure I prsented the problem.
Option Strict On
Option Explicit On
Imports System.ComponentModel
[Code].....
I have an application that interacts with third party COM objects. A method of the COM object that I call will sometimes stop responding. I created a Backgroundworker thread to call the function and I am trying to monitor it from my main thread to kill it if it hangs. I have additional code (not supplied) that tracks the processing time using system.timer from the main thread and I raise an event if it exceeds my threshold (this part is fine). This is when I want to kill the thread and stop code execution. The problem is.. if I use the cancelasync method it will just pend since the code execution is stuck on the function call.
The particular function call in the code snippet that hangs is "objCOM.SendDataToServer()". It typically takes 1-3 seconds to return, but if it gets no response it will just hang indefinitely and won't return at all (no errors just hangs).. there is no timeout... and since I don't have access to the source function I cannot supply one. I tried the .dispose() method of the thread, but apparently that doesn't kill it and neither does cancelasync. I just need help figuring out how to KILL this thread so I can reset the server connection and call the function again.
Public Class COMobject
Private objCOM as new acs.manager
Public Sub CallComFunction()
[code]....
I need a static variable to get a ListItemCollection from a List control (I can do this, but if I don't set it as Shared It's not preserving the values as it should). The thing is that this class is a SharePoint webpart, so I most probably will be using the webpart more than once, and I need this variable to be unique to each webpart, which shared doesn't accomplish.I tried everything you can imagine. I placed a Static variable within a Sub (shared and not shared), I tried it with Properties (also Shared and not shared)...
View 3 RepliesI have designed a class for posting data to server, which is a time consuming task so that i have used background worker in my application. instead of repeatedly using backgroundworker in my application, i decided to add it to my class and generate two events PostWorkerReportProgress, PostWorkerComplted for my application
View 1 Replies I am trying to create a tool which executes some oracle procedures and telnet commands. Besides this Job my tool also needs to update a counter in some table in oracle db at regular intervals(10 secs as per current settings). So I used backgroundworker class in VB.NET to implement this back ground job of updating the counter. My problem is I have put logs at every possible exit of the backgroundworker_dowork functions but still this logic stops working after some time --7-8 hours. I am not able to understand when/where/why/how is it stopping? I am saying logic has stopped because it stops incrementing the counter. And am saying it is exiting abruptly because in _RunWorkerCompleted, I have written a log and closed the application but nothing comes in the log and application is not exiting.
Private Sub backlogicthread_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles backlogicthread.DoWork
WriteLog("Background worker", "entered")
dbbackcontrol = New OracleConnection(odbcBill)
Dim dr As OracleDataReader
[Code] .....
I have a class which has various methods that I need to make public to only 1 other class. Is this possible? I don't want to make them public for everybody, just that 1 class.
View 1 RepliesIm creating a registration application where i have a listbox that displays a Course Name column and a Credit Hours column. I also have a textbox that keeps a running total of the credit hours of each course added to the list. When i remove a specific item from the list, i also want to subtract the number of the selected item from the running total in the text box. Essentially i just want to subtract a certain part of a list item from a variable i have.
View 1 RepliesI'm working with .NET 3.5 and Nunit 2.5.10. I'm attempting to write some tests to validate our role-based security enforcement through the PrincipalPermissionAttribute at a class-level. The test appears to succeed (it gets a green checkmark) and the Assert.Throws call properly catches the exception, and all my other assertions about the exception pass. However, once TearDown is complete after a test has run, the exception is re-thrown by NUnit. So even though the test "passed", every one of the tests shows that an exception was unhandled exception was thrown 'while executing' the test run.
I'm guessing I'm doing something wrong, but can't figure it out. My test is:
Public Sub New_TheForm_NoRoles_DeniesAccess()
' attempt to create a new instance of the form, but it should throw an exception with an inner SecurityException
Dim ex As TypeInitializationException = Assert.Throws(Of
[Code]....
Basically, Initialize is normally called in the application with Nothing so that we use the Windows Principal. During unit testing, we instead initialize it with a GenericPrincipal that has no roles, so that we can test that a SecurityException is thrown.
The tests are passing, but NUnit just seems to be re-throwing the exception post-Teardown.
I have a BackgroundWorker in a vb.net program that is doing a lengthy data import routine. I want to modify its RunWorkerAsync method so that it fires a custom event on completion of the method. (So that a method in an automated process can respond to the event and resume its work). In a sense I want to 'extend' the RunWorkerAsync method to add an extra line of code--but I can't 'see' the code in the method (to just add the line raising the event) because BackgroundWorker is an MSDN class from Microsoft.The only solution that I can think of is to 'wrap' the background worker class in a wrapper that calls the .RunWorkerAsync method and then raises the event.
Public sub wrapperMethod()
myBackgroundWorker.RunWorkerAsync()
raise customEvent
end sub
Is there a design pattern that I might use? An easy way to address this with the .net language?
PS: Unfortunately, I'm automating some clanking legacy software and backgroundworker is used in many locations, so wrapping the backgroundworker will be a bit of work and may open bugs.
I had a strange problem editing a class in the property grid whereby the property grid would refresh incorrectly.I managed to reduce the problem down to a class with just two properties. I've included the code at the end to ease explanation.It basically boils down to a class with two properties. The first of which is expandable (a font)The class itself is expandable and also implements the CreateInstance method in the type converter.To see the problem, expand the font, edit, say 'Bold', and tab away. Two problems happen:
(1) The second property jumps up and ends up in the expanded font property.
(2) The '-' sign of the expanded font changes to a '+'.
The problem goes away by attaching ResfreshProperties(RefreshProperties.All) to the class. That's great, but I'd like to understand how it fixed the problem. I've had a look in reflector and can't find any examples of RefreshProperties being attached at the class level.
[code]...
Here is the structure that I have:
Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer
[code].....
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
[Code]...
I am trying to create an list or an array of a class.Here is my "Ingredient" class that I am trying to create a list of:[code]In my "recipe" class, I am want to create a list (or array) and I am drawing a big blank on how to do it. Can anyone point me in the right direction?
View 2 Repliesin my button click event i ececure
If BackgroundWorker4.IsBusy Then
BackgroundWorker1.CancelAsync()
End If[code]....
after proceess completed if press the button again.i got the following error msg
This BackgroundWorker is currently busy and cannot run multiple tasks concurrently.
dim myCollection as new Specialized.StringCollection
dim myFoundThings as new ArrayList
dim index as Integer
dim newResultMemberName as String
[code]....
This is part of some code that will run without user interaction once it's spinning away, and I need to create a unique object from some items found in a StringCollection, naming the objects using information found in the strings stored in that StringCollection.
I'd like to have something like:
[Code]...
i've created bunch of classes. i have webservices which reference these classes and contains the classes as parameters and return objects.when i call the weservice, i have to convert the class to the webservice object else i can type conversion error.is there a generic way to convert between these types without having to assign the values by hand?
for example
public class person
fname as string
lname as string
end class
[code]....
i would liek ot be able to call the web service and return the data type back and have a generic coversion instead of as above in stead of:
dim wsPerson as wsReference.Person = ws.getperson()
I am creating an Excel add-in written in VB.NET. I would like to bind KeyDown and KeyUp events to the spreadsheet to record when the user presses and releases the arrow keys while navigating the spreadsheetIdeally, these events would be built into Excel alongside the native SheetActivate and SheetSelectionChange events, for example. Alas, they are not.
View 1 RepliesI have a class in which some of the fields are also classes.
I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"
But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition
dados_Defenicao.arCode = "123"
dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
If we are within the derived class then ofcource we can use MyBase keyword to access base class's object reference . That's fine , how can we take that base class's object reference outside that derived class's definition.My following code will explain what i want . Actually that is giving error right now, but it is explaining my requirement .
Public Class Base
Public x As String
End Class
[code]....
Actually there is error in ReadOnly Property BaseReference's Getter . Error is "Error 1 'MyBase' must be followed by '.' and an identifier. " how can i get base class object reference in Main method ?
If my namespace is Company.Application.EDI.Acknowledgement and if I stick with theprogramming practice of one class per file then should my class be saved asacknowledgement.vb? Are there any gotchas that will come up?
View 5 Replies