分享

[C#]richtextbox实现行号

 鸿枫nh 2015-11-12
editorControl是一个userControl,其包含两个控件:左侧是一个用来显示行号的RichTextBox(使用label等均可),右侧是一个继承自RichTextBox的componenteditorGrid1。
/*实现行号 begin*/
(1) 添加事件
        private void richTextBoxMain_TextChanged(object sender, EventArgs e)
        {
            updateLabelRowIndex();
        }
        private void richTextBoxMain_FontChanged(object sender, EventArgs e)
        {
            updateLabelRowIndex();
            richTextBoxMain_VScroll(null, null);
        }
        private void richTextBoxMain_Resize(object sender, EventArgs e)
        {
            richTextBoxMain_VScroll(null, null);
        }
        private void richTextBoxMain_VScroll(object sender, EventArgs e)
        {
            //move location of numberLabel for amount of pixels caused by scrollbar
            int p = richTextBoxMain.GetPositionFromCharIndex(0).Y % (richTextBoxMain.Font.Height + 1);
            labelRowIndex.Location = new Point(0,p);
            updateLabelRowIndex();
        }
(2)更新行号的函数
        private void updateLabelRowIndex()
        {
            //we get index of first visible char and number of first visible line
            Point pos = new Point(0,0);
            int firstIndex = this.richTextBoxMain.GetCharIndexFromPosition(pos);
            int firstLine = this.richTextBoxMain.GetLineFromCharIndex(firstIndex);
            //now we get index of last visible char and number of last visible line
            pos.X += this.richTextBoxMain.ClientRectangle.Width;
            pos.Y += this.richTextBoxMain.ClientRectangle.Height;
            int lastIndex = this.richTextBoxMain.GetCharIndexFromPosition(pos);
            int lastLine = this.richTextBoxMain.GetLineFromCharIndex(lastIndex);
            //this is point position of last visible char,
            //we'll use its Y value for calculating numberLabel size
            pos = this.richTextBoxMain.GetPositionFromCharIndex(lastIndex);
            labelRowIndex.Text = "";
            for (int i = firstLine; i <= lastLine +1 ; i++)
            {
                labelRowIndex.Text += i + 1 + "\r\n";
            }
        }    
        /*end*/

    本站是提供个人知识管理的网络存储空间,所有内容均由用户发布,不代表本站观点。请注意甄别内容中的联系方式、诱导购买等信息,谨防诈骗。如发现有害或侵权内容,请点击一键举报。
    转藏 分享 献花(0

    0条评论

    发表

    请遵守用户 评论公约

    类似文章 更多