I want some Moore

C# : Get current Caret Line and Column in a multiline Windows Forms TextBox

I can't believe these properties aren't already natively implemented. Come on Microsoft... we do live in the year 2007 you know!!

I know that you can do this using P/Invoke and SendMessage but i wanted a nice managed way of finding

the current line and column of the Caret position in a multiline TextBox.

After a bit of experimenting i've come up with this extended class:

public class TextBoxEx : TextBox
{
    public TextBoxEx()
    { }

    public void GoTo(int line, int column)
    {
        if (line < 1 || column < 1 || this.Lines.Length < line)
            return;
        
        this.SelectionStart = this.GetFirstCharIndexFromLine(line - 1) + column - 1;
        this.SelectionLength = 0;
    }

    public int CurrentColumn
    {
        get { return this.SelectionStart - this.GetFirstCharIndexOfCurrentLine() + 1; }
    }
 
    public int CurrentLine
    {
        get { return this.GetLineFromCharIndex(this.SelectionStart) + 1; }
    }
}

Hope you find it usefull. If anyone knows a better way do let me know.

UPDATE: With a bit of help from Andrej this is a better and shorter version with set method too.

Print | posted on Friday, October 19, 2007 3:40 PM