如何动态实现纵横向合并table

Question

Refer this:
合纵连横(GridView或Repeater)控件

Answer 1

这个纵横一起合并，咋弄呢。我自己写了个拼接字符串的横向合并方法，感觉效率不高
string TableHtml(DataTable dt)
    {
        System.Text.StringBuilder html = new System.Text.StringBuilder();
        foreach (DataRow row in dt.Rows)
        {
            html.Append("<tr>");
            //重复次数
            int repeatTimes = 1;
            //重复字段
            string repeatString = string.Empty;
            for (int i = 0;i < row.ItemArray.Length; i++)
            {
                if (repeatString == string.Empty)
                {
                    if (row.ItemArray[i].ToString() == string.Empty)
                        repeatTimes++;
                    repeatString = row.ItemArray[i].ToString();
                    continue;
                }
                if (row.ItemArray[i].ToString() == repeatString)
                {
                    repeatTimes++;
                    if (i == row.ItemArray.Length - 1)
                    {
                        html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes, repeatString));
                        repeatTimes = 1;
                        repeatString = string.Empty;
                    }
                }
                else
                {
                    if (repeatTimes > 1)
                    {
                        if (i == row.ItemArray.Length-1)
                        {
                            html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes+1, repeatString));
                            repeatTimes = 1;
                            repeatString = string.Empty;
                            continue;
                        }
                        html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes, repeatString));
                        repeatTimes = 1;
                    }
                    else
                    {
                        if (i == row.ItemArray.Length-1)
                        {
                            html.Append(string.Format("<td>{0}</td>", repeatString));
                            html.Append(string.Format("<td>{0}</td>", row.ItemArray[i].ToString()));
                            repeatString = string.Empty;
                            continue;
                        }
                        html.Append(string.Format("<td>{0}</td>", repeatString));
                    }
                    repeatString = row.ItemArray[i].ToString();
                }
            }
            html.Append("</tr>");
        }
        return html.ToString();
    }

Answer 2

发现一个bug，当字段为NULL或者String.Empty 的时候会出问题，自己画蛇添足了string TableHtml(DataTable dt)
    {
        System.Text.StringBuilder html = new System.Text.StringBuilder();
        foreach (DataRow row in dt.Rows)
        {
            html.Append("<tr>");
            //重复次数
            int repeatTimes = 1;
            //重复字段
            string repeatString = string.Empty;
            for (int i = 0;i < row.ItemArray.Length; i++)
            {
                string NowString = row.ItemArray[i] == null ? string.Empty : row.ItemArray[i].ToString();
                if (NowString == repeatString)
                {
                    repeatTimes++;
                    if (i == row.ItemArray.Length - 1)
                    {
                        html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes, repeatString));
                        repeatTimes = 1;
                        repeatString = string.Empty;
                    }
                }
                else
                {
                    if (repeatTimes > 1)
                    {
                        if (i == row.ItemArray.Length-1)
                        {
                            html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes+1, repeatString));
                            repeatTimes = 1;
                            repeatString = string.Empty;
                            continue;
                        }
                        html.Append(string.Format("<td colspan=\"{0}\">{1}</td>", repeatTimes, repeatString));
                        repeatTimes = 1;
                    }
                    else
                    {
                        if (i == row.ItemArray.Length-1)
                        {
                            html.Append(string.Format("<td>{0}</td>", repeatString));
                            html.Append(string.Format("<td>{0}</td>", NowString));
                            repeatString = string.Empty;
                            continue;
                        }
                        html.Append(string.Format("<td>{0}</td>", repeatString));
                    }
                    repeatString = NowString;
                }
            }
            html.Append("</tr>");
        }
        return html.ToString();
    }