How to add a line to a multiline TextBox?

Question

How can i add a line of text to a multi-line TextBox?

e.g. pseudocode;

textBox1.Clear(); textBox1.Lines.Add("1000+"); textBox1.Lines.Add("750-999"); textBox1.Lines.Add("400-749"); ...snip... textBox1.Lines.Add("40-59"); 

or

textBox1.Lines.Append("brown"); textBox1.Lines.Append("brwn"); textBox1.Lines.Append("brn"); textBox1.Lines.Append("brow"); textBox1.Lines.Append("br"); textBox1.Lines.Append("brw"); textBox1.Lines.Append("brwm"); textBox1.Lines.Append("bron"); textBox1.Lines.Append("bwn"); textBox1.Lines.Append("brnw"); textBox1.Lines.Append("bren"); textBox1.Lines.Append("broe"); textBox1.Lines.Append("bewn"); 

The only methods that TextBox.Lines implements (that i can see) are:

• Clone
• CopyTo
• Equals
• GetType
• GetHashCode
• GetEnumerator
• Initialize
• GetLowerBound
• GetUpperBound
• GetLength
• GetLongLength
• GetValue
• SetValue
• ToString

Answer 1

@Casperah pointed out that i'm thinking about it wrong:

• A TextBox doesn't have lines
• it has text
• that text can be split on the CRLF into lines, if requested
• but there is no notion of lines

The question then is how to accomplish what i want, rather than what WinForms lets me.

There are subtle bugs in the other given variants:

• textBox1.AppendText("Hello" + Environment.NewLine);
• textBox1.AppendText("Hello" + "\r\n");
• textBox1.Text += "Hello\r\n"
• textbox1.Text += System.Environment.NewLine + "brown";

They either append or prepend a newline when one (might) not be required.

So, extension helper:

public static class WinFormsExtensions {    public static void AppendLine(this TextBox source, string value)    {       if (source.Text.Length==0)          source.Text = value;       else          source.AppendText("\r\n"+value);    } } 

So now:

textBox1.Clear(); textBox1.AppendLine("red"); textBox1.AppendLine("green"); textBox1.AppendLine("blue"); 

and

textBox1.AppendLine(String.Format("Processing file {0}", filename)); 

Note: Any code is released into the public domain. No attribution required.

Answer 2

I would go with the System.Environment.NewLine or a StringBuilder

Then you could add lines with a string builder like this:

StringBuilder sb = new StringBuilder(); sb.AppendLine("brown"); sb.AppendLine("brwn");  textbox1.Text += sb.ToString(); 

or NewLine like this:

textbox1.Text += System.Environment.NewLine + "brown"; 

Better:

StringBuilder sb = new StringBuilder(textbox1.Text); sb.AppendLine("brown"); sb.AppendLine("brwn");  textbox1.Text = sb.ToString();