How to detect hidden characters in string (for example zero width space) during debugging

Question

Is there any easy way how to detect (during debugging), that string contains some hidden character (for example zero width space)?

Example: During debugging I'm comparing two differnet strings and they seem equal to my eyes. Of course they differ in some hidden charaters. How to find the difference?

I used string.ToCharArray() method in "Immediate window" of Visual Studio but there must be more comfortable way.

Answer 1

You can use this in the immediate window:

str.Contains("\u8203");

Or put it in the watch window so you'll just have to click the refresh button near the watched value to see the result, rather than re-entering it to the immediate (although you can always press up and then enter to re-enter the last command!)

To check for ANY hidden character, you can either have a static array with all hidden characters and check:

HIDDENS.Any(c => str.Contains(c.ToString())

And preferable even save the hidden characters as one-length strings and then do:

HIDDENS.Any(str.Contains)

OR you could be really sophisticated and do THIS:

private static readonly Bitmap BMP = new Bitmap(1000, 1000);
private static readonly Graphics GRAPHICS = Graphics.FromImage(BMP);
private static readonly Font FONT = new Font("Arial", 20);
private static readonly RectangleF RECT = new RectangleF(0, 0, 1000, 1000);

public static bool CheckInvisibleChars(string text)
{
    var stringFormat1 = new StringFormat(StringFormatFlags.MeasureTrailingSpaces);
    stringFormat1.SetMeasurableCharacterRanges(
        Enumerable.Range(0, text.Length - 2).Select(i => new CharacterRange(i, 1)).ToArray());

    return GRAPHICS.MeasureCharacterRanges(text, FONT, RECT, stringFormat1).Any(
        reg => reg.GetBounds(GRAPHICS).Width.Equals(0f));
}

From here it should also be easy to return information about each hidden character, etc.