richTextBox设置选中的字体属性

执行一次设置选中的字体样式 再执行一次恢复正常

//粗体

public void ToggleBold()
{

    if (richTextBox1.SelectionFont == null)
        richTextBox1.SelectionFont = richTextBox1.Font;

    FontStyle style = richTextBox1.SelectionFont.Style;

    if (richTextBox1.SelectionFont.Bold)

        style &= ~FontStyle.Bold;//恢复正常
    else
        style |= FontStyle.Bold;

    richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
}

斜体

public void ToggleItalic()
{
    if (richTextBox1.SelectionFont == null)
        richTextBox1.SelectionFont = richTextBox1.Font;

    FontStyle style = richTextBox1.SelectionFont.Style;

    if (richTextBox1.SelectionFont.Italic)
        style &= ~FontStyle.Italic;//恢复正常
    else
        style |= FontStyle.Italic;

    richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
}

下划线

public void ToggleUnderLine()
{
    if (richTextBox1.SelectionFont == null)
        richTextBox1.SelectionFont = richTextBox1.Font;

    FontStyle style = richTextBox1.SelectionFont.Style;

    if (richTextBox1.SelectionFont.Underline)
        style &= ~FontStyle.Underline;//恢复正常
    else
        style |= FontStyle.Underline;

    richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
}