backgroundworker

问题 Team, I have build a VB.Net windows application which does uploads data into database and basically updates two controls: 1. A textbox which is constantly updated with one line per database record upload. 2. A label which keeps track of the count of database record uploaded. I have used BackgroundWorker thread concept, where the thread's bgwWorker_DoWork() method contains the business logic for upload and bgwWorker_ProgressChanged() updates the 2 UI controls based on uploads. But the issue I

问题 ok.. so i have no idea why this is happening.I saw a similar problem in Java i guess.. but i don't understand any of that stuff. I am working with C# where I have a listview which is updated with remote servers update status on clicking of a button. i have got the code working for this. but when i click on the same button again, the output is displayed twice. If i click on it one more time the output is displayed thrice and so on!! for example: on first click: xxx login to server failed yyy

问题 Here's what I'm trying to solve: My class (which could be hosted by an UI app or a windows service or whatever), needs to receive windows messages. Somewhere around here, someone gave the suggestion (and some source code) to create a windows form in a separate thread that will create the form and whenever a windows message that I'm interested in receives on the WndProc, it triggers a delegate using context.Post. I've been trying to make it work but unsuccessfully. Instead of spending more

问题 According to literature I've read about QueueBackgroundWorkItem, I should be able to complete a long task in the background without being interrupted by IIS. What I'm wondering if is possible, if I start a long task and close my website before it completes, shouldn't the QueueBackgroundWorkItem finish the task? (it's not currently) Here are my calls: private async Task WriteTextAsync(CancellationToken cancellationToken) { string filePath = printPath; string text; byte[] encodedText = Encoding

问题 I’m trying to use events to update a textbox from a background worker from a different class. It is the same problem as mentioned in this SO post, except I'm using VB.NET. I'm trying to implement the 2nd suggested solution by @sa_ddam213. I’m getting an error: “Cross-thread operation not valid: Control 'txtResult' accessed from a thread other than the thread it was created on.” Here is my code: Public Class DataProcessor Public Delegate Sub ProgressUpdate(ByVal value As String) Public Event

问题 If i have a background worker that does some tasks in its do work String val= getVal("Val"); byte[] b = (byte[])e.Argument; b = getData.FromPlace(val); How do i pass the vakue of b to the runworkercompleted method? 回答1: You could use closure void Main() { var bw = new BackgroundWorker(); byte[] b; bw.DoWork += (sender, args) => { b = DoStuff(); }; } byte[] DoStuff() { String val= getVal("Val"); byte[] b = (byte[])e.Argument; b = getData.FromPlace(val); return b; } You could also use return

问题 The MSDN sample showed how to use the built-in System Triggers to start background tasks. How do you start a task without Trigger? Or how do you implement a custom Trigger? Some code would be nice. I am using XAML/C#. 回答1: According to this thread. Seems that you can't just launch a Background Task or make your own Trigger. In this case, a Metro app may not be appropriate... 来源： https://stackoverflow.com/questions/8859139/for-win-8-metro-app-how-to-start-background-task-immediately-without

问题 I am using a backgroundworker to fill a bunch of datasets using tableadapter.fill(). For some reason they are causing the UI to be unresponsive. How is this even possible? I'm not reporting any information back to the UI with it...it's just supposed to run in the background, no progressbar. Me.spOpportunityTableAdapter.Fill(Me.DsBdPipeline.spOpportunity, CType(ActiveStatus, Integer)) Me.ClientTableAdapter.Fill(Me.DsBdPipeline.Client) Me.ClientTypeTableAdapter.Fill(Me.DsBdPipeline.ClientType)

问题 Need to ask you for help as I'm struggling with this for too long now. Have gone over many tutorials but can't figure it out yet... In a first stage of this proyect I developed a console program that makes requests to a web server, processes the data and updates a MS Access DB. My problem arise now that after doing all that processing, I need to show the result inside a winform for the clients to see it, and even more the process should be going over and over again while the app is opened. So

问题 I am very new to C# and trying to understand background workers. Currently when I run this code it will stop redirecting and reading the output from the command prompt after the StopButton has been clicked and leaves the "cancelled" message behind, but then does nothing afterwards. I currently may be implementing this all wrong, but I have the e.Cancel set by clicking the stop button that calls CancelAsync(), which turns CancellationPending = true. Anyone have any ideas how I should go about