如何在Visual C＃中显示下标

Question

我正在为我的A级计算项目制作弹丸运动模拟程序，我需要将物理符号与订阅使用。我不知道如何在标签或丰富的文本框中使用它。任何人都可以给我帮助/代码以实施吗？

Answer 1

您需要在RichTextbox中使用SelectionCharoffset属性来完成此操作。

对于下标，使数字为负，因此：

richTextBox1.SelectionCharOffset = -10;

Answer 2

选择charroffset不是您的最佳选择。最好操纵RTF并添加下标。

//This allows you to reselect the text in the rtb after formatting
            int SelectionStart = richTextBox1.SelectionStart;
            int SelectionLength = richTextBox1.SelectionLength;
            string selectedRtf = richTextBox1.SelectedRtf;
            int Start;
            int End;
            string pre;
            string Mid;
            string post;
            //remove superscript from selected text
            Start = selectedRtf.IndexOf("\super");
            while (Start != -1)
            {
                pre = selectedRtf.Substring(0, Start);
                post = selectedRtf.Substring(Start + 6, selectedRtf.Length - (Start + 6));
                selectedRtf = pre.Trim() + post.Trim();
                Start = selectedRtf.IndexOf("\super");
            }
            //if selected text does not contain subscript
            if (selectedRtf.IndexOf("\sub") == -1 && selectedRtf.IndexOf("\nosupersub") == -1)
            {
                Start = selectedRtf.IndexOf("}}") + 2;
                End = selectedRtf.IndexOf("}", Start);
                pre = selectedRtf.Substring(0, Start);
                Mid = selectedRtf.Substring(Start, End - Start);
                post = selectedRtf.Substring(End, selectedRtf.Length - End);
                selectedRtf = pre + "\sub" + Mid + "\nosupersub" + post;
                goto Clean;
            }
            //if selected text contains subscript
            if (selectedRtf.IndexOf("\sub") > 0)
            {
                Start = selectedRtf.IndexOf("\sub");
                while (Start != -1)
                {
                    pre = selectedRtf.Substring(0, Start);
                    post = selectedRtf.Substring(Start + 4, selectedRtf.Length - (Start + 4));
                    selectedRtf = pre.Trim() + post.Trim();
                    Start = selectedRtf.IndexOf("\sub");
                }
                goto Clean;
            }

        Clean:
            richTextBox1.SelectedRtf = selectedRtf;
            richTextBox1.Focus();
            richTextBox1.SelectionStart = SelectionStart;
            richTextBox1.SelectionLength = SelectionLength;