Using parameters in BackgroundWorker handlers
For passing data to a BackgroundWorker
's DoWork
I use a separate wrapper class' instance:
MyParams mpar = new MyParams();
...
mpar.Par1 = par1val;
mpar.Par2 = par2val;
mpar.Par3 = par3val;
...
var worker1 = new开发者_开发技巧 System.ComponentModel.BackgroundWorker();
worker1.DoWork += new DoWorkEventHandler(worker1_DoWork);
worker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker1_RunWorkerCompleted);
worker1.RunWorkerAsync(mpar);
Then I can use parameters of mpar
instance in worker1_DoWork
, operating in another thread.
void worker1_DoWork(object sender, DoWorkEventArgs e)
{
//here we use mpar.Par1, mpar.Par2 and so on
}
In RunWorkerCompletedEventHandler
we do some postactions in UI thread.
My question is : Can we use in RunWorkerCompleted
handler the mpar
instance, which worked just before in DoWork
handler and can we be sure its values are the same it had in DoWork
? If not, what is the correct approach for sharing parameters for various stages of BackgroundWorker
operation?
void worker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
Dispatcher.BeginInvoke((Action)(() =>
{
//Can we use the mpar instance here?
}
));
}
You can assign the value of e.Result
in worker1_DoWork
static void worker1_DoWork(object sender, DoWorkEventArgs e)
{
//Do the work
//...
e.Result = new MyParams();
}
Then you can get it in the worker1_RunWorkerCompleted
in e.Result
.
If you need to pass additional result value and you don't want to put MyParams object in the worker1_DoWork: e.Result
- then you can create a small class ResultHolder
with MyParams
and MyResult
as properties and use that class to pass the result in worker1_DoWork
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