Question

What I am trying to do is to read in a file to a richTextBox automatically with the OnSelectedIndexChange method. There arent any errors, it just flat out doesnt work. Heres the code that I am working with

    public void comboBox1_OnSelectedIndexChanged(object sender, EventArgs e)
    {
        string selectedPath = comboBox1.SelectedItem.ToString();
        if (File.Exists(@"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt"))
        {
            try
            {
                Thread.Sleep(0500);
                System.IO.StreamReader textFile = new System.IO.StreamReader(@"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt");
                richTextBox1.Text = textFile.ReadToEnd();
                textFile.Close();
            }
            catch
            {                
                MessageBox.Show("Error: File cannot be opened!", "Error");
            }
        }
        else
        {
            MessageBox.Show("No comment was found in this folder", "Alert");
        }
    }

Answer 1

Just for fun, lets have you try something. First, replace the following line:

if (File.Exists(@"C:\\Mavro\\MavBridge\\" + selectedPath + "\\ " + "Comment" + ".txt"))

with this:

if(File.Exists(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath)))

It looks like you had an extra space ("\\ " + "Comment"), so I’m sure that’s why it never hits this block of code. Also, anytime you have an object that needs to be closed/disposed, more often than not it implements IDisposable, meaning you should encapsulate the object within a using block:

Thread.Sleep(0500);
try
{
    using(System.IO.StreamReader textFile = new System.IO.StreamReader(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath)))
    {
        richTextBox1.Text = textFile.ReadToEnd();
    }

}
catch
{                
    MessageBox.Show("Error: File cannot be opened!", "Error");
}

However, this can be simplified even further by bypassing the StreamReader entirely and using System.IO.File.ReadAllText instead:

richTextBox1.Text = System.IO.File.ReadAllText(string.Format("C:\\Mavro\\MavBridge\\{0}\\Comment.txt", selectedPath));