Question

I can send a message from my application by writing

port.WriteLine("AT+CMGS=\"" + m.Groups[2].Value + "\"");
port.Write(txt_msgbox.Text + char.ConvertFromUtf32(26));

This is fine. But now I want to send bulk messages to a group of numbers. I have this loop to send messages to a group of numbers:

foreach (ListViewItem item in bufferedListView1.Items)
{
    string lname = bufferedListView1.Items[i].Text;
    string lno = bufferedListView1.Items[i].SubItems[1].Text;
    string gname = bufferedListView1.Items[i].SubItems[2].Text;
    string line = lname + "@" + lno + "@" + gname;
    if (gname.Contains(sgroup))
    {
        var m = Regex.Match(line, @"([\w]+)@([+\d]+)@([\w]+)");
        if (m.Success)
        {
            port.WriteLine("AT+CMGS=\"" + m.Groups[2].Value + "\"");
            port.Write(txt_msgbox.Text + char.ConvertFromUtf32(26));
            Thread.Sleep(4000);
        }
        sno++;
    }
    i++;
}

This works well too. But the issue is with the UI, becoming irresponsive for quite a good amount of time. Any better ways to do it?

Answer 1

Use a BackgroundWorker – they are really easy to use and manage the threading in an encapsulated manner. The benefit of this class is that it supports cancellation if you want to be able to cancel the process and it supports reporting progress, both of which I’ll show here. Finally, the nice thing about this class is that when it reports progress it switches threads properly, ensuring you aren’t writing to the UX on a separate thread – but the code inside the DoWork event handler is still managed correctly on a separate thread.

You would do something like the following.

// in this example this is scoped to the class, but just scope it appropriately
private BackgroundWorker worker = new BackgroundWorker();

......

// because I don't really know anything about how your program is structured I'm not sure
// where you want to place all of the definitions OR where you want to place RunWorkerAsync
// but you want the definitions to happen ONCE and the RunWorkerAsync to be where the USER
// initiates it

// this will allow you to consume the ProgressChanged event
worker.WorkerReportsProgress = true;

// this will allow you to set the CancellationPending property
worker.WorkerSupportsCancellation = true;

worker.DoWork += (o, args) =>
{
    foreach (ListViewItem item in bufferedListView1.Items) 
    { 
        string lname = bufferedListView1.Items[i].Text; 
        string lno = bufferedListView1.Items[i].SubItems[1].Text; 
        string gname = bufferedListView1.Items[i].SubItems[2].Text; 
        string line = lname + "@" + lno + "@" + gname; 
        if (gname.Contains(sgroup)) 
        { 
            var m = Regex.Match(line, @"([\w]+)@([+\d]+)@([\w]+)"); 
            if (m.Success) 
            { 
                port.WriteLine("AT+CMGS=\"" + m.Groups[2].Value + "\""); 
                port.Write(txt_msgbox.Text + char.ConvertFromUtf32(26)); 
                Thread.Sleep(4000); 
            } 
            sno++; 
        } 
        i++; 
    }
}

worker.ProgressChanged += (s, args) =>
{
    // set some progress here, the ProgressChangedEventArgs inherently supports an integer
    // progress via the ProgressPercentage property
}

worker.RunWorkerCompleted += (s, args) =>
{
    // with the RunWorkerCompletedEventArgs class you can check for errors via Error, did
    // cancellation occur via Cancelled, and you can even send a complex result via the Result
    // property - whatever you need
}

// this starts the work in the DoWork event handler
worker.RunWorkerAsync();

Here is a link to Microsoft’s documentation on this matter.