read text file chunks by chunks by scrollbar [closed]

This is a working example of reading a text file per stream to accomplish what you are trying to do. I have tested it with a 100 MB text file, and it worked well, but you have to see if larger files work as well.

This is the example. Just bring a RichTextBox to your form and a VScrollBar. Then use a file ‘test.txt’ on your hard drive ‘C:’.

public partial class Form1 : Form
{
    const int PAGE_SIZE = 64;   // in characters
    int position = 0;  // position in stream

    public Form1()
    {
        InitializeComponent();
    }

    private void vScrollBar1_Scroll(object sender, ScrollEventArgs e)
    {
        position = e.NewValue * PAGE_SIZE;

        ReadFile(position);    
    }

    private void ReadFile(int position)
    {
        using (StreamReader sr = new StreamReader(@"C:\test.txt"))
        {
            char[] chars = new char[PAGE_SIZE];
            sr.BaseStream.Seek(position, SeekOrigin.Begin);
            sr.Read(chars, 0, PAGE_SIZE);

            string text = new string(chars);
            richTextBox1.Text = text;
        }    
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        ReadFile(position);
    }
}