BackgroundWorker C# with Example



BackgroundWorker C# with Example

See below for a simple example of how to use a BackgroundWorker object to perform time-intensive operations in a 
background thread. 
You need to: 
1. Define a worker method that does the time-intensive work and call it from an event handler for the DoWork 
event of a BackgroundWorker. 
2. Start the execution with RunWorkerAsync. Any argument required by the worker method attached to DoWork 
can be passed in via the DoWorkEventArgs parameter to RunWorkerAsync. 
In addition to the DoWork event the BackgroundWorker class also defines two events that should be used for 
interacting with the user interface. These are optional. 
The RunWorkerCompleted event is triggered when the DoWork handlers have completed. 
The ProgressChanged event is triggered when the ReportProgress method is called. 
public void ProcessDataAsync() 
{ 
// Start the time  intensive  method 
BackgroundWorker bw = new BackgroundWorker(); 
bw.DoWork += BwDoWork; 
bw.RunWorkerCompleted += BwRunWorkerCompleted; 
bw.RunWorkerAsync(@"PATH_TO_SOME_FILE"); 
//  Control  returns  here  before  TimeintensiveMethod  returns 
Console.WriteLine("You can read this while TimeintensiveMethod is still running."); 
} 
// Method that will be called after BwDoWork exits 
private void BwRunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
{ 
// we can access possible return values of our Method via the Parameter e 
Console.WriteLine("Count: " + e.Result); 
} 
 

// execution of our time intensive Method 
private void BwDoWork(object sender, DoWorkEventArgs e) 
{ 
e.Result = TimeintensiveMethod(e.Argument); 
} 
private int TimeintensiveMethod(object file) 
{ 
Console.WriteLine("Start TimeintensiveMethod."); 
//  Do  some  time  intensive  calculations... 
using (StreamReader reader = new StreamReader(file.ToString())) 
{ 
string s = reader.ReadToEnd(); 
for (int i = 0; i < 10000; i++) 
s.GetHashCode(); 
} 
Console.WriteLine("End TimeintensiveMethod."); 
// return something as a "result" 
return new Random().Next(100); 
} 

0 Comment's

Comment Form