Set/Unset Italic in RichTextBox

Question

I have a RTF box in my C# WinForms app.

Setting basic styles is fairly simple but when I try to unset the Italic style I lose all other applied styles to the selection font.

if (rtf.SelectionFont.Style.HasFlag(FontStyle.Italic))
{
     rtf.SelectionFont = new Font(rtf.SelectionFont.FontFamily, rtf.SelectionFont.Size, rtf.SelectionFont.Style | FontStyle.Regular);
}
else
{
     rtf.SelectionFont = new Font(rtf.SelectionFont.FontFamily, rtf.SelectionFont.Size, rtf.SelectionFont.Style | FontStyle.Italic);
}

Is there a way to just de-select the italic property without losing the Bold,underline ect.

FontStyle.Regular is 0, it doesn't change anything. You have to use the ~ operator, as shown in [this answer](http://stackoverflow.com/a/3153514/17034). — Hans Passant, Feb 24 '14 at 01:55
The `&` and `~` operators in conjunction will work, but _have to_ is overstated - [TMTOWTDI](http://en.wikipedia.org/wiki/TMTOWTDI), ["potato, potato, tomato, tomato"](http://answers.yahoo.com/question/index?qid=20100307223452AAAez19) etc. — J0e3gan, Feb 24 '14 at 02:29
Possible duplicate of [Substract Flag From FontStyle (Toggling FontStyles) \[C#\]](http://stackoverflow.com/questions/4198429/substract-flag-from-fontstyle-toggling-fontstyles-c) — Jim Fell, May 20 '16 at 14:38

score 2 · Answer 1 · answered Feb 24 '14 at 01:40

You should try iterating over the enumeration and putting the style back together. Something like the following:

FontStyle oldStyle = rtf.SelectionFont.Style;
FontStyle newStyle = FontStyle.Regular;
foreach (Enum value in Enum.GetValues(oldStyle.GetType()))
{
    if (oldStyle.HasFlag(value) && !value.Equals(FontStyle.Italic))
    {
        newStyle = newStyle | (FontStyle)value;
    }
}

rtf.SelectionFont = new Font(rtf.SelectionFont.FontFamily, rtf.SelectionFont.Size, newStyle);

J0e3gan · Accepted Answer · 2014-02-24T06:11:09.490

Use an XOR rather than an OR to remove a single FontStyle - for example:

private void btnBold_Click(object sender, EventArgs e)
{
    var currentStyle = rtf.SelectionFont.Style;
    var newStyle =
        rtf.SelectionFont.Bold ?
        currentStyle ^ FontStyle.Bold :
        currentStyle | FontStyle.Bold;

    rtf.SelectionFont =
        new Font(
            rtf.SelectionFont.FontFamily,
            rtf.SelectionFont.Size,
            newStyle);
}

private void btnItalic_Click(object sender, EventArgs e)
{
    var currentStyle = rtf.SelectionFont.Style;
    var newStyle =
        rtf.SelectionFont.Italic ?
        currentStyle ^ FontStyle.Italic :
        currentStyle | FontStyle.Italic;

    rtf.SelectionFont =
        new Font(
            rtf.SelectionFont.FontFamily,
            rtf.SelectionFont.Size,
            newStyle);
}

With this implementation, removing the bold or italic style will not affect the other style if it is already applied to the selection.

BONUS:

For additional considerations like reselecting the selection after changing its style, an old DevX tip of the day might interest you too.

Also, the common logic in the style-specific handlers I offered begs to be factored out into a helper method that the style-specific handlers can leverage - e.g. private ChangeStyle(FontStyle style).

interesting. Thanks I will try this too – IEnumerable Feb 24 '14 at 02:02 — IEnumerable, Feb 24 '14 at 02:02

Set/Unset Italic in RichTextBox

2 Answers2

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