Question

question:

Can i perform a flush like function to a richtextbox?

reason:

I am writing ~20-40 lines of text at a time to a richtextbox using a loop, my issue is that the whole GUI freezes during that time and nothing can be seen until everything has been written to the richtextbox and the code moves on. I want to write each line to the screen immediately if possible to avoid freezing. I know in console i can use a aFileStream.Flush() command to perform this function. Is there a similar function for aFileStream.appendtext()? My googleFu is weak today and i cant find any examples of this online. Any help is appreciated.

sample code:

 foreach (string fullPath in appDataDirectories)
                {
                    //update progess bar
                    progresbarupdate();
                    //split file path in to parts
                    string[] folders = fullPath.Split('\\');
                    //print out create time for directory
                    DateTime creationTimeUtc = Directory.GetCreationTimeUtc(fullPath);
                    String ctime = creationTimeUtc.ToString();
                    //create String
                    String printable = String.Format("{0,-50}\t{1}", ctime, fullPath);
                    output.AppendText(printable + "\n");
                }

Answer 1

I don’t think so you will be able to achieve the unfreezing of the RichTextBox by a flush

You can use the BackgroundWorker to do some work in the background on a separate thread and then invoke the Text action of the RichTextBox

Please see my example that shows the RichTextBox does not freeze

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        BackgroundWorker bg = new BackgroundWorker();
        bg.DoWork += new DoWorkEventHandler(bg_DoWork);
        bg.RunWorkerAsync();
    }

    void bg_DoWork(object sender, DoWorkEventArgs e)
    {
        for (int i = 0; i < 1000000000; i++)
        {
            Action action = () => richTextBox1.Text += "Line Number " + i;
            richTextBox1.Invoke(action); 
        }
    }
}