在富文本框中显示行号c#

Question

我有一个多行 Richtextbox 控件，我想将添加行号的功能集成到该控件中。我考虑了很多方法

1. 添加标签并随着行数的变化更新行号
2. 添加一个图片框并在其上绘制字符串。
3. 添加另一个文本框并在其上显示行号
4. 添加列表框并在其中显示行号。

我有两个疑问。

1. 我使用的richtextbox 是一个定制的控件，它来自RichTextBox 类。如何向它添加多个控件。
2. 在 c# 中显示多行文本的行号的最佳方法是什么

Answer 1

我自己的例子。一切都很好，但必须禁用自动换行 :(

    int maxLC = 1; //maxLineCount - should be public
    private void rTB_KeyUp(object sender, KeyEventArgs e)
    {
        int linecount = rTB.GetLineFromCharIndex( rTB.TextLength ) + 1;
        if (linecount != maxLC)
        {
            tB_line.Clear();
            for (int i = 1; i < linecount+1; i++)
            {
                tB_line.AppendText(Convert.ToString(i) + "\n");
            }
            maxLC = linecount;
        }
    }

rTB 是我的富文本框，tB 是 rTB 旁边的文本框

J.T.小号

Answer 2

此代码对我有帮助，谢谢，需要转换 Visual Basic 但可以：

Private Sub TextBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
    Dim maxlc As Integer = 1
    Dim linecount As Integer = TextBox1.GetLineFromCharIndex(TextBox1.Height) + 1

    If linecount <> maxlc Then
        TextBox2.Clear()
        For i = 0 To linecount - 1 Step 1
            TextBox2.AppendText(Convert.ToString(i) + vbNewLine)
        Next i
        maxlc = linecount
    End If
End Sub

Answer 3

100% 有效！！！但是你需要为行号添加richTextBox2，如果你想把它改成其他的 像列表框一样的形式，无论如何它对我很有帮助。

    private void richTextBox1_keyDown(object sender, KeyEventArgs e)
    {

        for (int i = 0; i <= richTextBox1.Lines.Count(); i++)
        {
            if (!(e.KeyCode == Keys.Back))
            {
                if (!richTextBox2.Text.Contains(i.ToString()))
                {
                    richTextBox2.Text += i.ToString() + "\n";
                }
            }
            else
            {
                richTextBox2.Clear();
            }
        }    
    } 

Answer 4

    public int getWidth()
    {
        int w = 25;
        // get total lines of richTextBox1
        int line = richTextBox1.Lines.Length;

        if (line <= 99)
        {
            w = 20 + (int)richTextBox1.Font.Size;
        }
        else if (line <= 999)
        {
            w = 30 + (int)richTextBox1.Font.Size;
        }
        else
        {
            w = 50 + (int)richTextBox1.Font.Size;
        }

        return w;
    }

    public void AddLineNumbers()
    {
        // create & set Point pt to (0,0)
        Point pt = new Point(0, 0);
        // get First Index & First Line from richTextBox1
        int First_Index = richTextBox1.GetCharIndexFromPosition(pt);
        int First_Line = richTextBox1.GetLineFromCharIndex(First_Index);
        // set X & Y coordinates of Point pt to ClientRectangle Width & Height respectively
        pt.X = ClientRectangle.Width;
        pt.Y = ClientRectangle.Height;
        // get Last Index & Last Line from richTextBox1
        int Last_Index = richTextBox1.GetCharIndexFromPosition(pt);
        int Last_Line = richTextBox1.GetLineFromCharIndex(Last_Index);
        // set Center alignment to LineNumberTextBox
        LineNumberTextBox.SelectionAlignment = HorizontalAlignment.Center;
        // set LineNumberTextBox text to null & width to getWidth() function value
        LineNumberTextBox.Text = "";
        LineNumberTextBox.Width = getWidth();
        // now add each line number to LineNumberTextBox upto last line
        for (int i = First_Line; i <= Last_Line + 2; i++)
        {
            LineNumberTextBox.Text += i + 1 + "\n";
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        LineNumberTextBox.Font = richTextBox1.Font;
        richTextBox1.Select();
        AddLineNumbers();
    }

    private void richTextBox1_SelectionChanged(object sender, EventArgs e)
    {
        Point pt = richTextBox1.GetPositionFromCharIndex(richTextBox1.SelectionStart);
        if (pt.X == 1)
        {
            AddLineNumbers();
        }
    }

    private void richTextBox1_VScroll(object sender, EventArgs e)
    {
        LineNumberTextBox.Text = "";
        AddLineNumbers();
        LineNumberTextBox.Invalidate();
    }

    private void richTextBox1_TextChanged(object sender, EventArgs e)
    {
        if (richTextBox1.Text == "")
        {
            AddLineNumbers();
        }
    }

    private void richTextBox1_FontChanged(object sender, EventArgs e)
    {
        LineNumberTextBox.Font = richTextBox1.Font;
        richTextBox1.Select();
        AddLineNumbers();
    }

    private void LineNumberTextBox_MouseDown(object sender, MouseEventArgs e)
    {
        richTextBox1.Select();
        LineNumberTextBox.DeselectAll();
    }

    private void Form1_Resize(object sender, EventArgs e)
    {
        AddLineNumbers();
    }