Substract Flag From FontStyle (Toggling FontStyles

问题:

I have a little problem. I have one 1 RichTextBox and 2 Buttons.

I have that 2 buttons for "toggle Bold FStyle" and "toggle Italic FStyle".

I want to toggle FontStyles without affecting other FontStyles. I hope you understand me.

Below code works when combining FontStyles but is not working when seperating/substracting FontStyles.

private void button1_Click(object sender, EventArgs e)
{
    richTextBox1.SelectionFont = new Font(richTextBox1.Font, (richTextBox1.SelectionFont.Bold == false ? richTextBox1.SelectionFont.Style | FontStyle.Bold : richTextBox1.SelectionFont.Style));
}

private void button2_Click(object sender, EventArgs e)
{
    richTextBox1.SelectionFont = new Font(richTextBox1.Font, (richTextBox1.SelectionFont.Italic == false ? richTextBox1.SelectionFont.Style | FontStyle.Italic : richTextBox1.SelectionFont.Style));
}

1. I make selected text Bold
2. I make selected text Italic
3. I want to remove Italic while Bold is still active (or opposite)

回答1:

The easiest way is to use bitwise XOR (^), which just toggles the value:

private void button1_Click(object sender, EventArgs e)
{
    richTextBox1.SelectionFont = new Font(richTextBox1.Font,
        richTextBox1.SelectionFont.Style ^ FontStyle.Bold);
}

private void button2_Click(object sender, EventArgs e)
{
    richTextBox1.SelectionFont = new Font(richTextBox1.Font,
        richTextBox1.SelectionFont.Style ^ FontStyle.Italic);
}