Linebreak in WinForms Textbox

Question

I'm having some trouble dealing with linebreaks here. Basically, the user puts in some data to a textbox that is then saved directly to the database.

When I display the data in my program, I only want to display the first line of the textbox, so I tried

Regex newLine = new Regex("/[\r\n]+/");
String[] lines = newLine.Split(row[data.textColumn.ColumnName].ToString());
SomeLabel.Text = lines[0];

But it display me all lines after another, so if the user puts in

a
b
c

The label displays

abc

How can I get this to work so it only displays the first line?

Answer 1

var data = row[data.textColumn.ColumnName].ToString();

And one of these (both work with unix and windows line-seperators). The first is fastest because it does not split every line when your only using the first.

int min = Math.Min(data.IndexOf("\r\n"), data.IndexOf("\n"));

string line;

if (min != -1)
    line = data.Substring(0, min);
else
    line = data;

or

var lines = data.Split(new[] { "\r\n", "\n" }, StringSplitOptions.None);
var line = lines[0];

(See also a few extension methods I have posted here: http://stackoverflow.com/questions/3545833/how-can-i-convert-a-string-with-newlines-in-it-to-separate-lines/3552636#3552636)

Answer 2

Use:

string[] lines = String.Split(new string[] { "\r\n" }, row[data.textColumn.ColumnName].ToString());

Answer 3

(I have added this in another answer because this answer is rather large and I think it will make this thread more clear - please leave a comment if I should make it one answer)

I have made this extension method which often have its uses:

public static IEnumerable<string> Lines(this string data)
{
    using (var sr = new StringReader(data))
    {
        string line;

        while ((line = sr.ReadLine()) != null)
            yield return line;
    }
}

And you can get the first line with:

var line = data.Lines().First();

This should be a lot faster than .Split when only a subset of the lines is used.