Question 88288 in ASP.NET Question posted in
The official documentation can be found here.

How can I output text file's content line by line to a TextBox on ASP.NET?

I’m building a website in ASP.net and, in this case, I’m simply trying to read a .txt file and output it into a textbox whenever that page loads. I wrote this code so I could execute my idea:

protected void Page_Load(object sender, EventArgs e)
{
    foreach (string line in System.IO.File.ReadLines(@"file_path"))
    {
        TextBox1.Text = line;
    }
}

However, this is not working, as when I execute the website on this page, nothing loads. There is no exception that is being called or any error.
What can I do?
If you need more details or information, please don’t refrain from asking.

Edit: I think it’s important to say that I’ve tested doing

TextBox1.Text = "Hello World";

And that worked properly.

Tags:

2

Answers


  1. 0

    To read the first line, you can simply write this File.ReadLines(“YourFileName”).FirstOrDefault;

    You need to use the method File.ReadAllText. It reruns the string value. And you can then assign to Text property.

    File.ReadLines returns Ienumerable<string> not string .

    Login or Signup to reply.
  2. 0

    Well, to read the text, this works:

            string sFile = @"C:TEST2T.txt";
        string sTextData = File.ReadAllText(sFile);
        
        TextBox1.Text = sTextData;

    And if some some reason, you LEFT OUT some HUGE MASSIVE WHOPPER detail, say like you only want the first line of text from the file?

    Then this:

            string sFile = @"C:TEST2T.txt";
        string sTextData = File.ReadAllText(sFile);

        string strFirstLine = sTextData.Split(System.Environment.NewLine.ToCharArray())[0];

        TextBox1.Text = strFirstLine;

    FYI:

    Don’t forget to set the text box to multiline if you need/want to have more then one line of text display in that box.

    As pointed out, we can use this:

      File.ReadAllLines(sFile).FirstOrDefault();

    however, the above still reads the whole text file.

    If the text file is to be large, and we still want the first line, or wish to read + process line by line, then this is better:

                StreamReader sR = new StreamReader(sFile);
            int i = 0;
            while (!sR.EndOfStream)
            {
                i++;
                Debug.Print(i.ToString() + "->" + sR.ReadLine());
                if (i >= 1)
                    break;
            }
            sR.Close();

    So, above would read line by line, and if the text file was large, or we wish to only pull + read the first line from the file? Then of course the above example is better, since only the first line (or several lines if i condition is changed) is better from a performance + io point of view.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search