用于粗体和/或斜体的 RichTextBox 字体样式按钮（如何编码以便可以选择多个而不是替换

Question

现在我正在使用一些带有以下代码的按钮：

richTextBox1.SelectionFont = new Font("Tahoma", 12, FontStyle.Bold);
richTextBox1.SelectionColor = System.Drawing.Color.Red;

我还想使用以下方法添加一些粗体、斜体等按钮：

richTextBox1.SelectionFont = new Font("Tahoma", 12, FontStyle.Italic);

但如果我有粗体选项，此代码将删除粗体并添加斜体。如何保留粗体和斜体？

谢谢！

Answer 1

这对我有用希望对你们有帮助......

private void cmdBold_Click(object sender, EventArgs e)
{
   Font new1, old1;
   old1 = rtxtBox.SelectionFont;
   if (old1.Bold)
      new1 = new Font(old1, old1.Style & ~FontStyle.Bold);
   else
      new1 = new Font(old1, old1.Style | FontStyle.Bold);

   rtxtBox.SelectionFont = new1;
   rtxtBox.Focus();
}

private void cmdItalic_Click(object sender, EventArgs e)
{
  Font new1, old1;
  old1 = rtxtBox.SelectionFont;
  if (old1.Italic)
    new1 = new Font(old1, old1.Style & ~FontStyle.Italic);
  else
    new1 = new Font(old1, old1.Style | FontStyle.Italic);

  rtxtBox.SelectionFont = new1;      

  rtxtBox.Focus();
}

private void cmdUnderline_Click(object sender, EventArgs e)
{
  Font new1, old1;
  old1 = rtxtBox.SelectionFont;
  if (old1.Underline)
    new1 = new Font(old1, old1.Style & ~FontStyle.Underline);
  else
    new1 = new Font(old1, old1.Style | FontStyle.Underline);

  rtxtBox.SelectionFont = new1;
  rtxtBox.Focus();
}

字体大小

private void cmbSize_KeyPress(object sender, KeyPressEventArgs e)
    {
      if (e.KeyChar == 13)
      {
        if (float.Parse(cmbSize.Text.Trim()) == 0)
        {
          MessageBox.Show("Invalid Font Size, it must be Float Number", "Invalid Font Size", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
          cmbSize.Text = "10";
          return;
        }
        if (cmbSize.Text.Trim() != "")
        {
          Font new1, old1;
          old1 = rtxtBox.SelectionFont;
          new1 = new Font(FontFamily.GenericSansSerif, float.Parse(cmbSize.Text.Trim()), old1.Style);
          rtxtBox.SelectionFont = new1;
        }
        rtxtBox.Focus();
      }
    }