Cancel A Task Which Is Not Performing Any Loop-based Statements?
Mar 27, 2012
I have an asynchronous task that is executing a function. The function does not contains any looping statements, but instead it is executing series of sql commands on sql server. Now, i have a button on my window that can cancel these sql operations. In other words, cancel the whole asynchronous task.
I know that this technique will require CancellationTokenSource and CancellationToken to cancel the task, but i've seen many examples on the internet and all of them are showing that the function that task is executing contains loop statements in which they are checking for IsCancellationRequested boolean property. But in my case, it is not so. My function does not have any loop statements in which i can do a check on this boolean property.
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Oct 16, 2009
i'm trying to set a discount to a product between two dates / times.Is it possible to achieve it?Are there any examples
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Aug 1, 2010
I'm using a BackgroundWorker to perform some analysis on a separate thread. The BackgroundWorker is called when a user clicks a CheckBox.
I need to provide for the user clicking the CheckBox, starting the BackgroundWorker task, and then changing their mind and clicking the CheckBox again.I simply want to cancel the currently running task and set the analysis off again. Currently I have the following method:
Public Sub UpdateParkStatusAsync()
Try
'Debug output.
Console.WriteLine("UC_Map_ViewModel.UpdateParkStatus called.")
[code]....
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Feb 27, 2009
i have a function to export data with some loops now the problem is that when he is exporting the data the program stop responding and only respond when the job is done, and i need a option to cancel the job when it is running but the problem simple block all forms that is opened how can i creat some multi task for fix that problem?
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Feb 27, 2009
i have a function to export data with some loops now the problem is that when he is exporting the data the program stop responding and only respond when the job is done, and i need a option to cancel the job when it is running but the problem simple block all forms that is opened how can i creat some multi task for fix that problem?
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Feb 27, 2009
i have a function to export data with some loops now the problem is that when he is exporting the data the program stop responding and onlyrespond when the job is done, and i need a option to cancel the jobwhen it is running but the problem simple block all forms that is openedhow can i creat some multi task for fix that problem?
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May 31, 2012
I have ...
Private Sub TestTask()
Debug.Write("Running")
For i As Integer = 0 To 60
[code]......
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Jun 17, 2011
Is it possible to define my list of strings like in 'good old' VB60, to use only on ebyte of memory for each character? .NET always seems to store any string as unicode, which doubles the required memory. The case is that I have a huge list of strings, all of the same size. It is about 50.000.000 items, 12 characters each. You can imagine I am running out of memory in no time. I tried converting them to arrays-of-bytes but in that case I loose the possibility to perform a "LIKE" statement in a FOR-EACH loop to check for a specific item.
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Jul 20, 2011
Is there any direct way to stop a threadpool when user press Cancel Task button? I got SmartThreadPool but using that i could not arrange my code. Its becoming difficult.
Here is my simple code:
'Delegaet to update UI
Public Delegate Sub updateClassDelegate(ByVal index As Integer, ByVal status As String)
[Code].....
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Mar 15, 2012
I've been able to write a thread into my app which basically does a loop in the background perfroming detection for a device being added or removed.works great!i am trying to implement another thread to check for a file on the found device...but i still haven't figured out threading enough to make this work, the versions i try to implemt are either looping along with the initial loop or cancelling itself because its already running.i've been trying to put a variable in that would switch the thread off, but it doesn't seem to work.
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May 14, 2009
I guess this is really a Visual Basic question, but I am trying to implement a choice of Strings statements based upon the month.
example: I am making a monthly free drawing, and I have made a SQL db table that has the months as the primary, then the prizes. I want to be able in VB to get the current date (which I can do) and make 12 IF statements that are the Months so that the proper data is pulled from the table.
IF CurrentDateTime.Month = 1 then SelectStatement = "SELECT FirstPrize, SecondPrize, ThirdPrize FROM MonthlyDrawing WHERE Month = January" and so on
So if I know how to get the current datetime, how do i access the month part and apply it? AnnualCountDownTime.Text = DateTime.Now.ToString("D" This is what I currently use to display the time.
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Jan 5, 2010
I need an additional loop argument within an If statement that resides in a very large do...loop block. It will speed the application considerably if I can have the do...loop block loop prematurely. I already have the remaining code after the additional loop argument in a large if...elseif block to achieve the result, but making it simply loop instead of going through this would speed the application.
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May 8, 2011
I have a piece of code that loops through the rows in a database and brings out information.
The code is attached to a button(search). To search for data, you enter a phone number, the loop goes through the data rows and bring out the information is it is there.
Everything works great accept I have added a second table to the database.
So do I add a whole new loop statement? Example lets say I had a new data row, how can I add that to this statement so that both tables are searched?
This is the code:
Dim strGetRecord As String = masTxtPhoneField.Text
For validData = 0 To storedtData.Rows.Count - 1
If strGetRecord = storedData.Rows(validData)("fldphone").ToString Then
[Code].....
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Dec 29, 2008
If you click on the backup button in my program, it starts to copy files from source to destination using a For loop.I can't cancel this For loop and I can't click on anything else in the window, because it won't respond untill the for loop completes.How can I let the program check if the Cancel button is pressed during the For loop and if pressed exit the loop?[code]...
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Oct 21, 2010
I am working on Datagridview. My task is adding buttons in the Datagridview table based on the case statements. Like In the Present table i have one column called "CategoryDescription". In this column, values are like 3101,3102, 3103........Here 31 is the common. and like 3201,3202,3203......Here 32 is the common. Like there are so many common values are there. So where ever the common values will come there i have to add one button in the Same column.
So Finally my conclsion is at Satrting 3101 and starting 3201,3301,3401.. i have to add one button control 3101 and add button control on 3201 and add button control on 3301.
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Jan 15, 2010
I am using Visual Studio .Net 2008. I am using "Structure" statement for my work. It is working with me perfectly. I am not sure if Understand the structure statement very well because it does give me wrong answer if I change the position of "Redim" of the structure elements. My problem is the structure is using "Redim" in many places which is a dangerous procedure. I do not know how exactly to explain my problem because the structure in my code is used widely and called in many subroutines. I will try to explain with the below simple code:
[code]...
My question is: How can I move the all "Redim" statements outside the loop so that the Redim happens only ones? What does "TheCollection(Iteration + NumberOfMembers).TheResult" does take? Is it zero or what?I searched the web but I could not find a proper website or article which explains the structure. The only useful link I found is this:[url]
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Jan 13, 2010
The following code works fine, however if the user wants to cancel out from the openfiledialog they cant they are stuck in a loop. A loop I created in case they selected the wrong type of data file they could choose again. [Code]. I really need some help seeing where and how to let the user cancel out without the program continuing. I tried some dialog.dispose code but everywhere i seem to put it it generates an error somewhere.
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Nov 17, 2011
I want to make it so when cancel is used it exits the loop but I need the Input as a decimal.
Do
txtItems.Text = intCounter.ToString
intCounter = intCounter + 1
msgInput = CDec(InputBox("Enter Item Price", "Item Price", ""))
decSubTotal = msgInput + decSubTotal
txtItemPrice.Text = msgInput.ToString("C2")
[Code] .....
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May 11, 2012
I have a method in a webservice that has parameter with which users can decide how they want to order their results. This is a List(Of String) with the names of the fields in the order they want to sort them. I know I can normally order on multiple columns by doing the following
Dim test = Bars.OrderBy(Function(x) x.Foo) _
.ThenBy(Function(x) x.Bar) _
.ThenBy(Function(x) x.Test)
However in this case this won't work since I can't chain the ThenBy function because I'm adding the sorting orders in a loop. To use ThenBy I need an IOrderedQueryable collection. This is how I would want it to work
Dim sortColumns = {"Foo", "Bar", "Test"}
Dim query = From b in Bars
For each column in sortColumns
Select Case column
Case "Foo"
query = query.Orderby(Function(x) x.Foo)
[Code] .....
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Mar 20, 2011
I have several text boxes I need to validate. I am not understanding how to validate in Visual Basic 2008. So I deployed standard If Statements to handle bad data. I am having two problems.
Lets say the user entered wrong data, example, numbers; an error message is displayed. The text boxes cannot contain numbers, be left empty or contained characters, like !@#$. The problem is if the user enter text, and then entered a wrong data again the code does not work or display error message. How can I make the conditions so that they throw out error message even if the user had previously entered good data.
Another example: If the user enter good data in text box 1 and bad data in text box 2, the error message does not work.
Finally, how do I filter out characters to allow only text. Is there a way to use this code on multiple text boxes with out writing the entire code for each form control?
Here are the conditional statements.
Private Sub btnDataSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDataSubmit.Click
If IsNumeric(txtDataEntry.Text) Then
lblErrorDisplay.Text = "Invalid Name!"
lblErrorDisplay.BackColor = Color.Red
[Code] .....
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Apr 19, 2010
I am an intermediate programmer with a basic understanding of VB.NET, however, I am having a problem with a special loop named "recursive".
To select the 3rd subitem/node inside a control named "CrumbBar", I have to:
CrumbBar1.SelectedItem = CrumbBar1.Items(0).SubItems(0)
CrumbBar1.SelectedItem = CrumbBar1.Items(0).SubItems(0).SubItems(1)
CrumbBar1.SelectedItem = CrumbBar1.Items(0).SubItems(0).SubItems(1).SubItems(2)
And go through all items, but I need to do this in a LOOP. And I don't know how many nodes I will have to go inside. So I wanna know how can I loop the above code?
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May 18, 2006
I validate a DataGridView with the CellValidating-eventhandler.That works fine. However, I want to avoid validating when the user presses the Cancel button. In the sequence validation occurs before the event CancelButton.Clicked.
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Oct 11, 2009
Can someone give me a site to a tutorial that will help me write a program that will generate a pattern using do while, if else statements,and do until statements. I have been using google but I can't find anything. I need to generate patterns a certain size 6 by 6 or similar such as something like a checkerboard but where the ^ symbols is there a suppose to be a blank space..
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Jan 20, 2011
I just want to repeat a code block if a CheckBox it's checked...So, i'm very novice to programing in Visual Basic and i'm learning by myself doing little things like a Ping Tool.I have this code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Label1.Text = ""
[code].....
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Dec 4, 2007
I am trying to implement a progress bar which increments based on a For Next Loop. The idea being that the increment should occur prior to the next go around of the loop. I have a user control form called "Progress" with a progress control on it called "Bar". The Min Value will be 0, Max 20, and Increment 1.
For X = 1 to 20
Code Here
'Put Increment here>>>>>>
Next
I have put the following code in the in the UserControl below. However its not clear to me how/where I trigger the bar to increment.
CODE IN USER CONTROL
Public Class Progress
Public Property Value() As Integer[code]......
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Jun 12, 2011
Attached is a visual representation of My Array that was used in my VB6 program the dimensions are:
CODE:
I am using an ACCESS DataBase to populate the array.
Using the For Next Loop I can access any position within the array such as a individual cell or group of cells. Also using the Step Keyword of the For next loop I can select a group of cells to manipulate based on the Step factor. This worked well for me in VB 6. I am now migrating to vb 2010 and cannot fine documentation as to how this would be done on zero based arrays in Vb 2010.
In VB 2010 I see no reference to the Step Keyword nor examples of how it would be used with zero based Arrays.
A example of my use of the step keyword is:
CODE:
Any of the above loop setups works for me using VB6 Any Documentation or code would be use in my vb6 to vb2010 migration?
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Dec 1, 2010
I am writing a program in VB 2008 and i need to be able to select different pages. i have a ComboBox with 15 values in it, and based on what value the user selects, that is the Form i want it to go to. for example, if i run the program and select the Value "electrical", then it will take me to the form that corresponds with that selection. [code]...
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Sep 21, 2011
i want to do this: when user click save button, the form must be check first..
if user did not insert the required data, user are not allow to save form..
the code:
Private Sub AssetMasterBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles AssetMasterBindingNavigatorSaveItem.Click
[Code].....
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Nov 24, 2010
is it guaranted that a task A started before TaskB will be completed before task B assuming the task do the same level of operatons?or in other words is there a chance that a task B will finish before tast A in the assumption that the task calls the same procedure?
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Mar 13, 2011
Im coding an interest rate calculator and I need a close clause for the textbox and the combo box using e.cancel and im getting a "cancel is not a member of "System.EventArgs" error
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