In VB.net, I tested concatenating 100k strings and found out one thread alone did it in 23 milliseconds. Two threads (each concatenating 50k) then joining the two at the end took 30 milliseconds. Performance wise, it didn't seem beneficial to utilize multiple threads when dealing with only 100k concatenations. Then I tried 3 million string concatenations and two threads each handling 1.5MM always demolished one thread handling all 3 million. I imagine at some point using 3 threads becomes beneficial, then 4, and so on. Is there a more efficient way to concatenate millions of strings in .NET?
I have a simple question about string concatenation. Following is the code. I want to ask why s6 = "abcde" and not "akcde"? I have change the s2 value to "k".
Public Class Form1 Public s1 As String = "a" Public s2 As String = "b"
The below program throws a runtime error (invalid conversion from double) because there is [code]It compiles fine, but when the program is run, it throws a runtime error.Is this a compiler bug? Shouldn't it stop me with a compiler error, like invalid syntax ?
Possible Duplicate: The difference between + and & for joining strings in VB.Net.In VB.NET you can use either += or &= to concatenante a string (ignoring using a StringBuilder for this question -- this is directed at a very simple concatenation).
I'm trying to concatenate two properties into one string like so:
public class thing public property word() as string() public property count() as integer()
[Code]....
This is what I want, but it doesn't help that its in the debug output...I need to put it into a single string. I've tried using a_thing.count(i).tostring, but it doesnt work. If I look at the arrays individually, they have exactly the contents I want. But I can't concatenate them. Does it have something to do with suppressing the new line that debug.writeline usually creates?
The intent of the code is to open an xls file -minimize it , search for keywords . there are columns like test case name ,priority(simple ,medium and high) with associated keywords.If keywords are found, it shld save the test case name - Priority in a text box. When i run this code i am getting err in
I've got a small app which I use to start a 3rd party application. When run from a shortcut the VB app starts the 3rd party app to and when loaded it displays its own file/folder interface, the VB app the closes itself. However, if you open a file in explorer associated with the 3rd party app, the 3rd party application loads and opens the file itself and not the file/open interface.
Uh OK, so what's the problem??The issue is I have changed the file extension associated with the 3rd party app to now use my VB app. I can successfully open files with the app from explorer if there are no spaces in the file or folder path however if there are, the 3rd party app opens and displays a File not found error message and gives the path up to the point where the space then follows.The relevant snippets of code from the app relating to the issue is below, specifically Dim Arguments variable where I am not quite sure how my string cocantenation should be to deal with the value of the variable 'Filename' which may or may not contain spaces.
The following output produces a string with no closing xml tag. m_rFlight.Layout = m_rFlight.Layout + "<G3Grid:Spots>" + Me.gvwSpots.LayoutToString() + "</G3Grid:Spots>"
I just had a new, last-minute idea on to take on a task, so I am running to StackExchange for quick help.
What I want to do is execute a series of methods right in a row, each in their own threads. I want the application to wait until all of these threads are completed, after which the program will resume. It also has to use managed threading (thread pool).
What quick examples could you provide to help me along the way? If it's too complex, what things should I know about so that I can Google it on my own?
I have a main thread which is designed to be a batch processor - it spawns a series of 'child' threads from a loop (which can vary in terms of the no of items) - see below
[Code]...
However, each of the 'child' threads could take anywhere from milliseconds to about a minute to process - depending on the complexity of each calculation. There may also be a large number of child threads - e.g 100s. Creating large numbers of child threads is not efficient. I therefore want some way to effectively queue each child thread (and cancel if the process is taking too long to complete). Autoevents seems like one way of doing this, but the only examples I can find seem to assume there are two different processes on seperate threads, not one process being repeated.
I have a application that writes and reads from a serial port.The com-port is opened elsewhere in the early stages of starting / running frm_Main and is not shown. I have a button1 on my form and when I click it, the module 'RTUValues_Get_IOData' executes perfectly ok, with no errors.[code]However when I call it via a thread [button2], I get the following exception error and it hangs, at the part shown above in RED"Conversion from string "" to type 'Double' is not valid."
I'm trying to improve performance of an application by introducing threading (see my earlier question). I have filled a Queue(of String) with XML messages and I now want to setup two threads to post these messages to a webserver). This process needs to ensure that each message is only posted once. Would a BackgroundWorker (or two) be suitable for this?
Is there any difference between & and + operators while concatenating string?if yes, then what is difference? And if No, then why below code generating exception?
Example:
Dim s, s1, t As String Dim i As Integer s1 = "Hello"
I am wondering how to concatenate a string and an integer to form a button name.eg, ("button" & x) where x is an integer to form button1, button2, etc so i can change the backcolor of the buttons.
I'm trying to compose a String from multiple Strings, where some of the Strings may be in Arabic letters, the problem is that when I concatenate them, their order is being messed !!
For example, I have the following Strings:
Ref1 مسكه 2 Left
I want to concatenate them with the same previous order seperated by "-", but instead I get Ref1-مسكه-2-Left, as you can see, 2 is written before مسكه Does anyone know how to fix this problem, because it's really important in my case to have the exact same order, and I don't know where or when I might have these arabic strings, because it's being entered by User.
I have a windows form having combobox and textbox controls.. I have to generate a part number, consisting of combobox and textbox values included.. I can explain in detail.. This is the code i have used to define a variable "type"..
When I am concatenating object values together to form a string in VB.NET, is there a difference in performance or a recommended best practice between using the & concat or the + concat with calls to .ToString() on each object?
Example (which is faster or best practice):
Dim result1 As String = 10 & "em" Dim result2 As String = 10.ToString() + "em"
I have combobox for year and combobox for month concatenated to make the date format "2012-01" My db field is RecordDate and is smallDateTime In my select statement im trying to use the left function to find match my concatenated string to the RecordDate field.Here is my code, hopefully someone can help me. Currently im getting the error "Conversion failed when converting date and/or time from character string."
Dim newRecordDate As String = (CStr(ComboBox2.SelectedValue)) & "-" & val1 Dim val10 As String = CStr(Convert.ToDateTime(newRecordDate)) Dim val21 As String = Microsoft.VisualBasic.Right(val10, 7) MsgBox(val10)
The following code shoudl put 2 commas after each entry in the x array. It concatenates commas just file using an index. It does not concateante when you use "for each".
Sub SummaryHeadings() Dim x() As String = {"Found No Help", "One",
I need to run TWO Threads in a web application, .NET. 3.5 Both methods MakeRedCars and MakeBlueCars need to run at the same time as both take 5 seconds. I have tried many example codes with very bad results. I dont need anymore than 2 threads. The main issue I am having is knowing how to wait till they are finished and also how to store the results from each.Each of the Methods do different things, one is a web request, one is a sql call.
Both methods return a list of(cars) for example do:
carList.addrange(MakeRedCars()) carList.addrange(MakeBlueCars()) for each car in carlist<br> response.write(car.colour + "<r>") next
I have implemented the answered below and with empty objects all works well, as soon as you hook in a database call that returns the data/objects studio does a JIT and crashes.
I can only run "so many" threads concurretnly, a notion which I have seen elsewhere.As a threading novoice, how can I determine the maximum number of threads to use? Or is this a "how long is a piece of string" question? What does it depends on? Hardware config or what?
I am having an issue where I need to implement a type of thread scheduling... I'm looking to implement a list of tasks, each with a set time that they need to execute, and after the time is up they will execute the respective code that goes with that task. I would use a timer based solution, however, I don't think that it would be very efficient. There will be a very large list of tasks, some of which need to be executed within seconds of being placed in the list.
I have 2 thread.One that put some data inside a list?the second that take out these data from the same list.what is the best "list" that allows one thread to put something inside and another one that take stuff out>
My application generates some background threads to perform some slow jobs (a cycle of ask for a long process to a server - wait - download the result).
I'm having a bit of an issue killing threads off and resetting my form. After starting the threads, everything runs fine. When I want to cancel the threads, the threads are all killed off "properly" using the Abortable Thread Pool, but how do I know that all the threads are dead? I've tried using both GetAvailableThreads and GetMinThreads compared against the thread count that should be running if they're all killed off, but I can't seem to get it to work. The only time I can get the GetAvailableThreads to return the "correct" number is if I freeze one thread and kill off the rest.
