C# 如何在Richtextbox中的每行开头添加字符

我正在做一个应用程序，如果你点击按钮，它会为每一行添加一个特定的字符。例如，在Richtextbox中的每一行中输入“/”，并将文本涂成红色，这类似于VisualStudio中的注释输出功能

我试过了,但不管用

private void toolStripButton1_Click(object sender, EventArgs e)
    {
        int firstCharPosition = richTextBox1.GetFirstCharIndexOfCurrentLine();
        int lineNumber = richTextBox1.GetLineFromCharIndex(firstCharPosition);
        int lastCharPosition = richTextBox1.GetFirstCharIndexFromLine(lineNumber + 1);

        if (richTextBox1.SelectionLength > 0)
        {
            richTextBox1.SelectionColor = Color.Red;
            richTextBox1.SelectedText = "//" + richTextBox1.SelectedText.ToString();
        }
        else
        {
            richTextBox1.Select(firstCharPosition, lastCharPosition - firstCharPosition);
            richTextBox1.SelectionColor = Color.Red;
            richTextBox1.SelectedText = "//" + richTextBox1.SelectedText.ToString();
        }
    }

伙计们，请帮帮我，谢谢

这可能就行了

if (richTextBox1.SelectionLength >= 0 && richTextBox1.Text.Length > 0)
{
    int firstCharIndex = richTextBox1.GetFirstCharIndexOfCurrentLine();
    if (richTextBox1.SelectionLength == 0)
    {
        int lineNumber = richTextBox1.GetLineFromCharIndex(firstCharIndex);
        int lastCharIndex = richTextBox1.GetFirstCharIndexFromLine(lineNumber + 1);
        if (lastCharIndex == -1) lastCharIndex = richTextBox1.Text.Length;
        richTextBox1.Select(firstCharIndex, lastCharIndex - firstCharIndex);
        richTextBox1.SelectionColor = Color.Red;
        richTextBox1.SelectedText = "//" + richTextBox1.SelectedText;
        richTextBox1.Select(firstCharIndex--, lastCharIndex - firstCharIndex);
        richTextBox1.Focus();
    }
    else
    {
        int selStart = richTextBox1.SelectionStart;
        int selLen = richTextBox1.SelectionLength;
        richTextBox1.SelectionStart = selStart + selLen;
        int lastLineFirstChar = richTextBox1.GetFirstCharIndexOfCurrentLine();
        int lastLineNumber = richTextBox1.GetLineFromCharIndex(lastLineFirstChar);
        int lastLineLastChar = richTextBox1.GetFirstCharIndexFromLine(lastLineNumber + 1);
        if (lastLineLastChar == -1) lastLineLastChar = richTextBox1.Text.Length;

        string beforeSelection = richTextBox1.Text.Substring(0, firstCharIndex);
        string afterSelection = richTextBox1.Text.Substring(lastLineLastChar, richTextBox1.Text.Length - lastLineLastChar);
        string selectionText = richTextBox1.Text.Substring(firstCharIndex, lastLineLastChar - firstCharIndex);

        string[] lines = selectionText.Split(new string[] { Environment.NewLine, "\r", "\n", "\r\n" }, StringSplitOptions.RemoveEmptyEntries);
        string commentedText = "";
        for (int i = 0; i < lines.Length; i++) commentedText += "//" + lines[i] + "\r\n";

        richTextBox1.Text = beforeSelection + afterSelection;
        richTextBox1.SelectionStart = firstCharIndex;
        richTextBox1.SelectedText = commentedText;
        richTextBox1.Select(firstCharIndex, lastLineLastChar - firstCharIndex + (lines.Length * 2));
        richTextBox1.SelectionColor = Color.Red;
        richTextBox1.Focus();
    }
}

if（richTextBox1.SelectionLength>=0&&richTextBox1.Text.Length>0）
{
int firstCharIndex=richTextBox1.GetFirstCharIndexOfCurrentLine（）；
如果（richTextBox1.SelectionLength==0）
{
int lineNumber=richTextBox1.GetLineFromCharIndex（firstCharIndex）；
int lastCharIndex=richTextBox1.GetFirstCharIndexFromLine（行号+1）；
如果（lastCharIndex==-1）lastCharIndex=richTextBox1.Text.Length；
richTextBox1.选择（firstCharIndex，lastCharIndex-firstCharIndex）；
richTextBox1.SelectionColor=Color.Red；
richTextBox1.SelectedText=“/”+richTextBox1.SelectedText；
richTextBox1.选择（firstCharIndex--，lastCharIndex-firstCharIndex）；
richTextBox1.Focus（）；
}
其他的
{
int selStart=richTextBox1.SelectionStart；
int selLen=richTextBox1.SelectionLength；
richTextBox1.SelectionStart=selStart+selLen；
int lastLineFirstChar=richTextBox1.GetFirstCharIndexOfCurrentLine（）；
int lastLineNumber=richTextBox1.GetLineFromCharIndex（lastLineFirstChar）；
int lastLineLastChar=richTextBox1.GetFirstCharIndexFromLine（lastLineNumber+1）；
如果（lastLineLastChar==-1）lastLineLastChar=richTextBox1.Text.Length；
string beforeSelection=richTextBox1.Text.Substring（0，firstCharIndex）；
string afterSelection=richTextBox1.Text.Substring（lastLineLastChar，richTextBox1.Text.Length-lastLineLastChar）；
string selectionText=richTextBox1.Text.Substring（firstCharIndex，lastLineLastChar-firstCharIndex）；
string[]lines=selectionText.Split（新字符串[]{Environment.NewLine，“\r”，“\n”，“\r\n”}，StringSplitOptions.RemoveEmptyEntries）；
字符串commentedText=“”；
对于（int i=0；i

正确操作

RichTextBox

比更改

文本要复杂一些。下面是一个代码示例，它将帮助您

请注意，is从不直接更改
文本
，因此它不会弄乱以前的格式，并尝试恢复选择

它允许您独立地注释几个部分。它从
文本框
中获取注释字符串进行测试，并恢复为
黑色

// get all line numbers that belong to the selection
List<int> getSelectedLines(RichTextBox RTB)
{
    List<int> lines = new List<int>();

    int sStart = RTB.SelectionStart;
    int sEnd = RTB.SelectionLength + sStart;

    int line1 = RTB.GetLineFromCharIndex(sStart);
    int line2 = RTB.GetLineFromCharIndex(sEnd);

    for (int l = line1; l <= line2; l++) lines.Add(l);
    return lines;

}

// prefix a line with a string
void prependLine(RichTextBox RTB, int line, string s)
{
    int sStart = RTB.SelectionStart;
    int sLength = RTB.SelectionLength;

    RTB.SelectionStart = RTB.GetFirstCharIndexFromLine(line);
    RTB.SelectionLength = 0;
    RTB.SelectedText = s;

    RTB.SelectionStart = sStart;
    RTB.SelectionLength = sLength;
}

// color one whole line
void colorLine(RichTextBox RTB, int line, Color c)
{
    int sStart = RTB.SelectionStart;
    int sLength = RTB.SelectionLength;

    RTB.SelectionStart = RTB.GetFirstCharIndexFromLine(line);
    RTB.SelectionLength = RTB.Lines[line].Length; ;
    RTB.SelectionColor = c;

    RTB.SelectionStart = sStart;
    RTB.SelectionLength = sLength;

}

// additional function, may come handy..
void trimLeftLine(RichTextBox RTB, int line, int length)
{
    int sStart = RTB.SelectionStart;
    int sLength = RTB.SelectionLength;

    RTB.SelectionStart = RTB.GetFirstCharIndexFromLine(line);
    RTB.SelectionLength = length;
    RTB.Cut();

    RTB.SelectionStart = sStart;
    RTB.SelectionLength = 0;
}

// remove a string token from the start of a line
void trimLeftLine(RichTextBox RTB, int line, string token)
{
    int sStart = RTB.SelectionStart;
    int sLength = RTB.SelectionLength;

    RTB.SelectionStart = RTB.GetFirstCharIndexFromLine(line);
    RTB.SelectionLength = token.Length;
    if (RTB.SelectedText == token) RTB.Cut();

    RTB.SelectionStart = sStart;
    RTB.SelectionLength = 0;
}


//获取属于所选内容的所有行号
列出getSelectedLines（RichTextBox RTB）
{
列表行=新列表（）；
int ssstart=RTB.SelectionStart；
int sEnd=RTB.SelectionLength+ssStart；
int line1=RTB.GetLineFromCharIndex（sStart）；
int line2=RTB.GetLineFromCharIndex（发送）；
对于（int l=line1；l
if（richTextBox1.Text.Length>0&&richTextBox1.SelectionLength>=0）
{
string[]lines=richTextBox1.Text.Split（新字符串[]{Environment.NewLine，“\n”，“\r”，“\r\n”}，StringSplitOptions.RemoveEmptyEntries）；
颜色normalColor=Color.Black，commentColor=Color.Red；
int selStart=richTextBox1.SelectionStart，selEnd=selStart+richTextBox1.SelectionLength，
STARTINE=-1，endLine=-1，lineSum=0，k=0；
对于（k=0；kselStart）
{
startine=k；
如果（selEnd=selEnd）
终点线=k；
}
否则就断了；
对于（int i=0；i行[i]=（i>=startLine&&i不客气。但是当我测试时，出现了一个问题。如果你不在乎，请跳过。否则我还有一个解决方案。为此，你必须在richTextBox中写10或12行。一起选择第3、4、5行。通过单击事件对其进行注释。它变为红色。之后，选择第6、7、8行并对其进行注释。它变为红色，但上面的行返回黑色。告诉我您是否需要解决方案hh我现在看到问题..如何解决此问题，先生？以及如果我有新按钮，如何取消注释已注释文本？感谢回答我sirhi先生，我发现了一个问题先生..我已经写了10行，我选择1和2并对其进行注释，在我选择2和4后，它变为红色，并显示rns红色所有10行我会看一看，并将从StringSplitOptions.RemoveEmptyEntries发布到StringSplitOptions.Nonesir现在工作正常，我如何在另一个按钮中取消注释注释注释行..请帮助我，先生，谢谢作为一个新问题提问。我会回答
private void button1_Click(object sender, EventArgs e)
{
    List<int> lines = getSelectedLines(richTextBox1);

    foreach (int l in lines) prependLine(richTextBox1, l, tb_comment.Text);
    foreach (int l in lines) colorLine(richTextBox1, l, Color.Firebrick);

}

private void button2_Click(object sender, EventArgs e)
{
    List<int> lines = getSelectedLines(richTextBox1);

    foreach (int l in lines) trimLeftLine(richTextBox1, l, tb_comment.Text);
    foreach (int l in lines) colorLine(richTextBox1, l, Color.Black);

}

if (richTextBox1.Text.Length > 0 && richTextBox1.SelectionLength >= 0)
    {
        string[] lines = richTextBox1.Text.Split(new string[] { Environment.NewLine, "\n", "\r", "\r\n" }, StringSplitOptions.RemoveEmptyEntries);
        Color normalColor = Color.Black, commentColor = Color.Red;
        int selStart = richTextBox1.SelectionStart, selEnd = selStart + richTextBox1.SelectionLength,
        startLine = -1, endLine = -1, lineSum = 0, k = 0;

        for (k = 0; k < lines.Length; k++)
            if (startLine == -1)
            {
                if ((lineSum += lines[k].Length + 1) > selStart)
                {
                    startLine = k;
                    if (selEnd <= lineSum) endLine = k;
                }
            }
            else if (endLine == -1)
            {
                if ((lineSum += lines[k].Length + 1) >= selEnd)
                    endLine = k;
            }
            else break;

        for (int i = 0; i < lines.Length; i++)
            lines[i] = (i >= startLine && i <= endLine ? "//" : "") + lines[i];

        richTextBox1.Text = "";
        richTextBox1.SelectionStart = 0;
        for (int i = 0; i < lines.Length; i++)
        {
            richTextBox1.SelectionStart = richTextBox1.Text.Length;
            richTextBox1.SelectionColor = lines[i].TrimStart().StartsWith("//") ? commentColor : normalColor;
            richTextBox1.SelectedText = lines[i] += (i == lines.Length - 1 ? "" : "\r\n");
        }

        int selectStarIndx = richTextBox1.GetFirstCharIndexFromLine(startLine), selectEndIndx = richTextBox1.GetFirstCharIndexFromLine(endLine + 1);
        if (selectEndIndx == -1) selectEndIndx = richTextBox1.Text.Length;

        richTextBox1.Select(selectStarIndx, selectEndIndx - selectStarIndx);
        richTextBox1.Focus();
    }