Solved

C# async & await

Posted on 2015-01-15
4
172 Views
Last Modified: 2015-01-18
Hi Experts,

I want to enumerate files in a folder and then process each file.  Normally I would have done this by creating a thread and updating the UI after each file was processed with the result.

Now I want to do this in an async and await style... I'm a bit stuck with code that looks a bit like this:

        public async void ProcessActions()
        {
            while (!m_bAllActionsProcessed)
                await Task.Run(() => ProcessNextAction());
        }

        private async Task ProcessNextAction()
        {
            if (m_nCurrentAction >= m_Actions.Count)
            {
                m_bAllActionsProcessed = true;
                return; // done.
            }

            Action<object> action = (object obj) =>
            {
                DirectoryAction directoryAction = m_Actions[m_nCurrentAction];
                DirectoryInfo info = new DirectoryInfo(directoryAction.GetDirectory());
                FileInfo[] files = info.GetFiles("*", directoryAction.GetRecurse() ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
                foreach (FileInfo fileInfo in files)
                    HandleFile(fileInfo);
            };

            // and now -->  also, how do I run this task??

Open in new window


Thanks!
Mike
0
Comment
Question by:thready
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 1

Author Comment

by:thready
ID: 40552754
Somehow I think I'm better off on this one using good old threads....
0
 
LVL 75

Accepted Solution

by:
käµfm³d   👽 earned 250 total points
ID: 40552864
First, you should check out the Channel 9 videos on async/await.

Second, as you'll find out in the videos, you should not be using async void for anything other than an event handler.

Third, async/await is good for I/O-bound operations, not CPU-bound operations. The reading of the files from disk is a good candidate for async/await; the processing of the files depends on what you mean by "processing" as to whether or not async/await makes sense.
0
 
LVL 86

Assisted Solution

by:Mike Tomlinson
Mike Tomlinson earned 250 total points
ID: 40552886
Not sure how things are getting fired off...or how your boolean and "m_nCurrentAction" variable are getting changed,  but try something like this out:
        private async void button1_Click(object sender, EventArgs e)
        {
            button1.Enabled = false;

            while (!m_bAllActionsProcessed) // <-- how is "m_bAllActionsProcessed" getting changed?...
                await Task.Run(() => ProcessNextAction());

            MessageBox.Show("Done!");
            button1.Enabled = true;
        }

        private void ProcessNextAction()
        {
            DirectoryAction directoryAction = m_Actions[m_nCurrentAction]; // <-- how is "m_nCurrentAction" getting changed?...
            DirectoryInfo info = new DirectoryInfo(directoryAction.GetDirectory());
            FileInfo[] files = info.GetFiles("*", directoryAction.GetRecurse() ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
            foreach (FileInfo fileInfo in files)
            {
                label1.Invoke((MethodInvoker)delegate { label1.Text = fileInfo.FullName; }); // some kind of progress update
                HandleFile(fileInfo);
            }   
        }

Open in new window

0
 
LVL 1

Author Closing Comment

by:thready
ID: 40556723
async & await are God's gift to programming.  Thanks for your help!
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

After several hours of googling I could not gather any information on this topic. There are several ways of controlling the USB port connected to any storage device. The best example of that is by changing the registry value of "HKEY_LOCAL_MACHINE\S…
Entering time in Microsoft Access can be difficult. An input mask often bothers users more than helping them and won't catch all typing errors. This article shows how to create a textbox for 24-hour time input with full validation politely catching …
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…

707 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question