使用大写字母和粗体格式化RichTextBox的第一行

Question

如果我有一个RichTextBox并希望第一行的输出是大写字母和粗体的字体，而下一行恰恰相反，我该怎么办？

输出是这样的：

MY NAME IS
戴安娜
我的地址是
中国

Answer 1

嘿试试这个，它的工作原理，但你可能看到的文字闪烁的第二个如果用户类型真的很快，例如按住“Enter”等。

private void Form_Load(object sender, EventArgs e) 
    { 
     // append the function to the RichTextBox's TextChanged event 
     MyRichTextBox.TextChanged += Capitalize_Bold_FirstLine; 
    } 

    private void Capitalize_Bold_FirstLine(object sender, EventArgs e) 
    { 
     RichTextBox box = sender as RichTextBox; 
     if (box != null && box.Text != "") 
     { 
      // get the current selection text of the textbox 
      int ss = box.SelectionStart; 
      int sl = box.SelectionLength; 
      // get the position where the first line ends 
      int firstLineEnd = box.Text.IndexOf('\n'); 
      if (firstLineEnd < 0) 
       firstLineEnd = box.Text.Length; 

      // split the lines 
      string[] lines = box.Text.Split('\n'); 
      // capitalize the first line 
      lines[0] = lines[0].ToUpper(); 
      // join them back and set the new text 
      box.Text = String.Join("\n", lines); 
      // select the first line and make it bold 
      box.SelectionStart = 0; 
      box.SelectionLength = firstLineEnd; 
      box.SelectionFont = new Font(box.Font, FontStyle.Bold); 
      // select the rest and make it regular 
      box.SelectionStart = firstLineEnd; 
      box.SelectionLength = box.Text.Length - firstLineEnd; 
      box.SelectionFont = new Font(box.Font, FontStyle.Regular); 
      // go back to what the user had selected 
      box.SelectionStart = ss; 
      box.SelectionLength = sl; 
     } 
    }