Sending Arguments To Background Worker

Question

Let s say I want to sent an int parameter to a background worker  how can this be accomplished   private void worker DoWork object sender  DoWorkEventArgs e         I know when this is worker RunWorkerAsync     I don t understand how to define in worker DoWork that it should take an int parameter

User · Answer

You should always try to use a composite object with concrete types (using composite design pattern) rather than a list of object types. Who would remember what the heck each of those objects is? Think about maintenance of your code later on... Instead, try something like this:

Public (Class or Structure) MyPerson
                public string FirstName { get; set; }
                public string LastName { get; set; }
                public string Address { get; set; }
                public int ZipCode { get; set; }
End Class

And then:

Dim person as new MyPerson With { .FirstName = “Joe”,
                                  .LastName = "Smith”,
                                  ...
                                 }
backgroundWorker1.RunWorkerAsync(person)

and then:

private void backgroundWorker1_DoWork (object sender, DoWorkEventArgs e)
{
        MyPerson person = e.Argument as MyPerson
        string firstname = person.FirstName;
        string lastname = person.LastName;
        int zipcode = person.ZipCode;                                 
}

User · Answer

You can pass multiple arguments like this  List lt object gt  arguments   new List lt object gt     arguments Add  quot first quot           argument 1 arguments Add new Object       argument 2        arguments Add 10               argument n  backgroundWorker RunWorkerAsync arguments    private void worker DoWork object sender  DoWorkEventArgs e       List lt object gt  genericlist   e Argument as List lt object gt       extract your multiple arguments from      this list and cast them and use them

User · Answer

you can try this out if you want to pass more than one type of arguments  first add them all to an array of type Object and pass that object to RunWorkerAsync   here is an example       some Method       List lt string gt  excludeList   new List lt string gt        list of strings    string newPath   some path       normal string    Object   args    newPath excludeList                backgroundAnalyzer RunWorkerAsync args             Now in the doWork method of background worker  backgroundAnalyzer DoWork object sender  DoWorkEventArgs e                  backgroundAnalyzer ReportProgress 50           Object   arg   e Argument as Object            string path   string arg 0           List lt string gt  lst    List lt string gt   arg 1                              do something

User · Answer

You start it like this   int value   123  bgw1 RunWorkerAsync argument  value       the int will be boxed   and then   private void worker DoWork object sender  DoWorkEventArgs e        int value    int  e Argument       the  argument  parameter resurfaces here                and to transport a result back to the main thread    double result   0 1   value     e Result   result         the Completed handler should follow this pattern     for Error and  optionally  Cancellation handling private void worker Completed object sender  RunWorkerCompletedEventArgs e          check error  check cancel  then use result   if  e Error    null              handle the error       else if  e Cancelled              handle cancellation       else                     double result    double  e Result           use it on the UI thread          general cleanup code  runs when there was an error or not

User · Answer

Check out the DoWorkEventArgs Argument Property       backgroundWorker1 RunWorkerAsync yourInt        private void backgroundWorker1 DoWork object sender  DoWorkEventArgs e           Do not access the form s BackgroundWorker reference directly         Instead  use the reference provided by the sender parameter      BackgroundWorker bw   sender as BackgroundWorker          Extract the argument      int arg    int e Argument          Start the time-consuming operation      e Result   TimeConsumingOperation bw  arg           If the operation was canceled by the user          set the DoWorkEventArgs Cancel property to true      if  bw CancellationPending                e Cancel   true

User · Answer

You can use the DoWorkEventArgs Argument property   A full example  even using an int argument  can be found on Microsoft s site    How to  Run an Operation in the Background

User · Answer

Even though this is an already answered question  I d leave another option that IMO is a lot easier to read   BackgroundWorker worker   new BackgroundWorker    worker DoWork     obj  e    gt  WorkerDoWork value  text   worker RunWorkerAsync      And on the handler method   private void WorkerDoWork int value  string text

User · Answer

You need RunWorkerAsync object  method and DoWorkEventArgs Argument property   worker RunWorkerAsync 5    private void worker DoWork object sender  DoWorkEventArgs e        int argument    int e Argument    5

[c#] Sending Arguments To Background Worker?

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