What is the fastest way to load text file into RichTextBox?

Question

I load text file into RichTextBox using OpenFIleDialog. But when a large amount of text is (for example song text about 50-70 lines) and I click OPEN program hangs for a few second (~3-5). Is it normal? Maybe there is some faster way or component to load text file? If my question is an inappropriate just delete it. Thanx.

if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            string text = File.ReadAllText(openFileDialog1.FileName);
            for (int i = 0; i < text.Length - 1; i++)
            {
                richTextBox1.Text = text;
            }
        }

I guess maybe ReadAllLines impeds it?

Can you post the code you're using to read the file and fill the richtextbox ? — digEmAll, Mar 16 '11 at 09:21

score 7 · Accepted Answer · edited May 23 '17 at 11:53

7

There is a similar question that deals with the fastest way of reading/writing files: What's the fastest way to read/write to disk in .NET?

However, 50-70 lines is nothing.. no matter how you read, it should fly in immediately. Are you maybe reading from a network share or something else that is causing the delay?

Edit: Now that I see your code: Remove the loop and just write richTextBox1.Text = text; once. It doesn't make sense to assign the string in the loop since you already read the complete content of the file by using ReadAllText.

if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK) {
    string text = File.ReadAllText(openFileDialog1.FileName);
    richTextBox1.Text = text;
}

edited May 23 '17 at 11:53

Community

1
1

answered Mar 16 '11 at 09:24

Christian

4,261
22
24

Thanx, I don't know, maybe my Pentium IV is weak, or ReadAllLines does it slow. – Frankie Drake Mar 16 '11 at 09:43
Thanx a lot. I've understood that loop is an inappropriate just now! Al answers are very helpfull. Thanx. – Frankie Drake Mar 16 '11 at 19:41

score 6 · Answer 2 · answered Mar 16 '11 at 09:51

void LoadFileToRTB(string fileName, RichTextBox rtb)
{
      rtb.LoadFile(File.OpenRead(fileName), RichTextBoxStreamType.PlainText); // second parameter you can change to fit for you
      // or
      rtb.LoadFile(fileName);
      // or
      rtb.LoadFile(fileName, RichTextBoxStreamType.PlainText); // second parameter you can change to fit for you
}

digEmAll · Answer 3 · 2011-03-16T09:53:25.267

2

Remove the for loop, because is useless:

string text = File.ReadAllText(openFileDialog1.FileName);
richTextBox1.Text = text;

text is a string that already contains all the text of the file to pass to the textBox.

Doing:

for(int i=0, i < text.Lengt-1; i++)
    richTextBox1.Text = text;

you're assigning the text read from the file text.Length-1 times (Length is the number of characters of the string) and that's useless.

edited Mar 16 '11 at 09:53

answered Mar 16 '11 at 09:47

digEmAll

56,430
9
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Thanx, the is useless, looking absurdly. – Frankie Drake Mar 16 '11 at 20:29

score 0 · Answer 4 · answered Mar 16 '11 at 09:57

0

if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
    richTextBox1.Text = File.ReadAllText(openFileDialog1.FileName);
}

answered Mar 16 '11 at 09:57

anar khalilov

16,993
9
47
62

What is the fastest way to load text file into RichTextBox?

4 Answers4

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