How Can I Remove Duplicate Lines From a textBox in C#?

Question

I have one text box the value is like that below

I tried:

textBox1.Text = string.Join("\r\n", **textBox1.Lines**.Distinct());

textBox1.Lines is not supporting to my program

If the text of the textbox is exactly what you wrote ("1 2 3 1 3") there are no duplicate lines, because you have only 1 line — Matteo Umili, Jul 22 '15 at 19:21
are you in winforms? what do you mean textBox1.Lines is not supporting? — imlokesh, Jul 22 '15 at 19:22
possible duplicate of [How can I remove duplicates from a TextBox?](http://stackoverflow.com/questions/4572987/how-can-i-remove-duplicates-from-a-textbox) — C-Pound Guru, Jul 22 '15 at 19:26

Salah Akbari · Answer 1 · 2015-07-23T08:05:40.190

1

Add this to using directives at top of page:

using System.Linq;

Then simply use like so:

textBox1.Text = string.Join(Environment.NewLine, textBox1.Lines.Distinct());

edited Jul 23 '15 at 08:05

answered Jul 22 '15 at 19:27

Salah Akbari

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score 1 · Answer 2 · answered Jul 22 '15 at 19:27

What do you think about that:

        string x = "1\r\n2\r\n1\r\n";

        string[] lines = x.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);
        var cmd = (from i in lines select i);
        string[] result = cmd.Distinct().ToArray();

        x = string.Join("\r\n", result);

score 1 · Answer 3 · answered Jul 22 '15 at 19:31

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string[] distinctLines = theText.Split(new string[] { Environment.NewLine }, StringSplitOptions.None).Distinct().ToArray();
textBox1.Text = string.Join("\r\n", distinctLines);

answered Jul 22 '15 at 19:31

Graffito

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score 0 · Answer 4 · answered Jul 22 '15 at 19:28

Even though the code you posted should work, here's a different approach.

textBox1.Text = string.Join(Environment.NewLine, textBox1.Text.Split(new[] {Environment.NewLine}, StringSplitOptions.None).Distinct());

Basically, you can split the text into lines yourself since you mention problems with Lines.

How Can I Remove Duplicate Lines From a textBox in C#?

4 Answers4