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Adding text to RichTextBox #C / WPF

Anonymous User 3922 17-Dec-2013

What I am trying to achieve is to add text after every operation to a RichTextBox. The problem is that these operations take some time and instead of viewing the appended text after every operation finishes, I view them all at the end of the routine.

Semi-Pseudo code:

RichTextBox richTextBox = new RichTextBox()
if (Operation1())
{
   richTextBox.AppendText("Operation1
finished");
   if (Operation2())
   {
     
richTextBox.AppendText("Operation2 finished");
      if
(Operation3())
      {
         richTextBox.AppendText("Operation3
finished");
      }
   }
}

The problem is that I view the appended text of operation 1 & 2 after the operation 3 is finished.

I read somewhere that I need to use something called BackgroundWorker???
wpf wpf 
Updated on 17-Dec-2013
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1 Answers

Pravesh Singh

Pravesh Singh

17-Dec-2013

Hi Jeet,

 

Using BackgroundWorker, you would just put the background work into DoWork, and the update into RunWorkerCompleted:


var bw1 = new BackgroundWorker();
var bw2 = new BackgroundWorker();
var bw3 = new BackgroundWorker();
bw1.DoWork += (sender, args) => args.Result = Operation1();
bw2.DoWork += (sender, args) => args.Result = Operation2();
bw3.DoWork += (sender, args) => args.Result = Operation2();
bw1.RunWorkerCompleted += (sender, args) => {
    if ((bool)args.Result)
    {
        richTextBox.AppendText("Operation1 ended\n");
        bw2.RunWorkerAsync();
    }
};
bw2.RunWorkerCompleted += (sender, args) => {
    if ((bool)args.Result)
    {
        richTextBox.AppendText("Operation2 ended\n");
        bw3.RunWorkerAsync();
    }
};
bw3.RunWorkerCompleted += (sender, args) => {
    if ((bool)args.Result)
    {
        richTextBox.AppendText("Operation3 ended\n");
    }
};
bw1.RunWorkerAsync();



You'll notice that this runs afoul of "DRY". You could always consider abstracting the tasks for each step using something like:


var operations = new Func<bool>[] { Operation1, Operation2, Operation3, };
var workers = new BackgroundWorker[operations.Length];
for (int i = 0; i < operations.Length; i++)
{
    int locali = i;    // avoid modified closure
    var bw = new BackgroundWorker();
    bw.DoWork += (sender, args) => args.Result = operations[locali]();
    bw.RunWorkerCompleted += (sender, args) =>
    {
        txt.Text = string.Format("Operation{0} ended\n", locali+1);
        if (locali < operations.Length - 1)
            workers[locali + 1].RunWorkerAsync();
    };
    workers[locali] = bw;
}
workers[0].RunWorkerAsync();

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