NPOI導出多表頭Execl(通過html表格遍歷表頭)

關於NPOI的相關信息，我想博客園已經有很多了，而且NPOI導出Execl的文章和例子也很多，但導出多表頭缺蠻少的；今天要講的通過自己畫html表格；通過html表格來導出自定義的多表頭；

先來看要實現的多表頭格式:

第一步：畫html表格（備注有一定的格式要求）

//td需要4個屬性，rowspan(跨行數)、colspan(跨列數)、row(所在行)、col(所在列)；備注：其實除了跨行和跨列數外，后面只需要所在列都可以了；

<tr>
                <td rowspan="2" colspan="1" row="0" col="0">名稱1</td>
                <td rowspan="2" colspan="1" row="0" col="1">名稱2</td>
                <td rowspan="2" colspan="1" row="0" col="2">名稱3</td>
                <td rowspan="1" colspan="4" row="0" col="3">名稱4</td>
                <td rowspan="1" colspan="4" row="0" col="7">名稱5</td>
                <td rowspan="1" colspan="4" row="0" col="11">名稱6</td>
                <td rowspan="1" colspan="4" row="0" col="15">名稱7</td>
                <td rowspan="2" colspan="1" row="0" col="19">名稱8</td>
                <td rowspan="2" colspan="1" row="0" col="20">名稱9</td>
                <td rowspan="2" colspan="1" row="0" col="21">備注</td>
            </tr>
            <tr>
                <td rowspan="1" colspan="1" row="1" col="3">效果1</td>
                <td rowspan="1" colspan="1" row="1" col="4">效果2</td>
                <td rowspan="1" colspan="1" row="1" col="5">效果3</td>
                <td rowspan="1" colspan="1" row="1" col="6">效果4</td>
                <td rowspan="1" colspan="1" row="1" col="7">效果5</td>
                <td rowspan="1" colspan="1" row="1" col="8">效果6</td>
                <td rowspan="1" colspan="1" row="1" col="9">效果7</td>
                <td rowspan="1" colspan="1" row="1" col="10">效果8</td>
                <td rowspan="1" colspan="1" row="1" col="11">效果9</td>
                <td rowspan="1" colspan="1" row="1" col="12">效果10</td>
                <td rowspan="1" colspan="1" row="1" col="13">效果11</td>
                <td rowspan="1" colspan="1" row="1" col="14">效果12</td>
                <td rowspan="1" colspan="1" row="1" col="15">效果13</td>
                <td rowspan="1" colspan="1" row="1" col="16">效果14</td>
                <td rowspan="1" colspan="1" row="1" col="17">效果15</td>
                <td rowspan="1" colspan="1" row="1" col="18">效果16</td>
            </tr>

第二步,解析html表格

1、正則遍歷tr

 string rowContent = string.Empty;
 MatchCollection rowCollection = Regex.Matches(html, @"<tr[^>]*>[\s\S]*?<\/tr>",
                    RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture); //對tr進行篩選

 2、循環tr正則遍歷td

   MatchCollection columnCollection = Regex.Matches(rowContent, @"<td[^>]*>[\s\S]*?<\/td>",
                      RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture); //對td進行篩選

3、解析td原屬

   var match = Regex.Match(columnCollection[j].Value, "<td.*?rowspan=\"(?<row>.*?)\".*?colspan=\"(?<col>.*?)\".*?row=\"(?<row1>.*?)\".*?col=\"(?<col1>.*?)\">(?<value>.*?)<\\/td>", RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture);
                        if (match.Success)
                        {
                            int rowspan = Convert.ToInt32(match.Groups["row"].Value);//表格跨行
                            int colspan = Convert.ToInt32(match.Groups["col"].Value);//表格跨列
                            int rowcount = Convert.ToInt32(match.Groups["row1"].Value);//所在行
                            int col = Convert.ToInt32(match.Groups["col1"].Value);//所在列
                            string value = match.Groups["value"].Value;//值
　　　　　　　　　　　　　　}

通過上面幾步，都可以解析出對應的表格原屬

使用NPOI

1、創建HSSFWorkbook

HSSFWorkbook hssfworkbook = new HSSFWorkbook();;//創建Workbook對象
 HSSFSheet sheet1 = (HSSFSheet)hssfworkbook.CreateSheet("測試多表頭");//創建工作表

2、在tr循環中創建行

//寫在tr循環中 
for (int i = 0; i < rowCollection.Count; i++){
HSSFRow row = (HSSFRow)sheet1.CreateRow(i);
rowContent = rowCollection[i].Value;
}

3、在td循環中創建列（關鍵）

 //遍歷td
for (int j = 0; j < columnCollection.Count; j++)
                    {
                        var match = Regex.Match(columnCollection[j].Value, "<td.*?rowspan=\"(?<row>.*?)\".*?colspan=\"(?<col>.*?)\".*?row=\"(?<row1>.*?)\".*?col=\"(?<col1>.*?)\">(?<value>.*?)<\\/td>", RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture);
                        if (match.Success)
                        {
                            int rowspan = Convert.ToInt32(match.Groups["row"].Value);//表格跨行
                            int colspan = Convert.ToInt32(match.Groups["col"].Value);//表格跨列
                            int rowcount = Convert.ToInt32(match.Groups["row1"].Value);//所在行
                            int col = Convert.ToInt32(match.Groups["col1"].Value);//所在列
                            string value = match.Groups["value"].Value;

                            if (colspan == 1)//判斷是否跨列
                            {
                                var cell = row.CreateCell(col);//創建列
                                cell.SetCellValue(value);//設置列的值
                                if (value.Length > 0)
                                {
                                    int width = value.Length * 25 / 6;
                                    if (width > 255)
                                        width = 250;
                                    sheet1.SetColumnWidth(col, width * 256);
                                }
                            }
　　　　　　　　　　　　　　　　//判斷是否跨行、跨列
                            if (rowspan > 1 || colspan > 1)
                            {
                                int firstRow = 0, lastRow = 0, firstCol = 0, lastCol = 0;
                                if (rowspan > 1)//跨行
                                {
                                    firstRow = rowcount;
                                    lastRow = firstRow + rowspan - 1;
                                }
                                else
                                {
                                    firstRow = lastRow = i;
                                }
                                if (colspan > 1)//跨列
                                {
                                    firstCol = col;
                                    int cols = col + colspan;
                                    for (; col < cols; col++)
                                    {
                                        var cell = row.CreateCell(col);
                                        cell.SetCellValue(value);
                                    }
                                    lastCol = col - 1;
                                }
                                else
                                {
                                    firstCol = lastCol = col;
                                }
　　　　　　　　　　　　　　　　　　//關鍵是這里，設置起始行數，結束行數；起始列數，結束列數
                                sheet1.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(firstRow, lastRow, firstCol, lastCol));
                            }

                        }
                    }

保存execl

           string year = DateTime.Now.Year.ToString();
           string ppath = HttpContext.Current.Server.MapPath(DateTime.Now.ToString("yyyyMMddmmss") + ".xls");
            FileStream file = new FileStream(ppath, FileMode.Create);
            hssfworkbook.Write(file);
            file.Close();

這樣都保存在服務器上了,可以通過下載自行下載下來；這里不復制代碼了；

如果有什么問題，請指教，謝謝！