項目中經常需要導出excel，有時還有彙總需求。但導出方式都一樣，而彙總方式不同。可以參考以下方式，使用標準的導出方式，和自定義的彙總方式。
1.首先NuGet引用NPOI version 2.3.0
2.導出表格源碼
/// <summary>
/// 【彙總的外置方法】func第一個參數是上次的行數據,第二個參數是當前行數據,第三個參數是Sheet中的當前行,第四個參數是否是最後一行數據,如果增加了新行,則必須返回true
/// </summary>
/// <param name="dt"></param>
/// <param name="func"></param>
/// <returns></returns>
public void ExportDataToExcel(DataTable dt, string FileName, Func<DataRow, DataRow, IRow,Boolean, Boolean> func)
{
HSSFWorkbook hssfworkbook = new HSSFWorkbook();
ICellStyle cellstyle = hssfworkbook.CreateCellStyle();//設置垂直居中格式
cellstyle.VerticalAlignment = VerticalAlignment.Top; //垂直居中
cellstyle.Alignment = HorizontalAlignment.Center; //居中
#region 初始化Sheets
List<ISheet> Sheets = new List<ISheet>();//Sheets集合
Action addSheet=()=>{
ISheet sheet = hssfworkbook.CreateSheet();
IRow row = sheet.CreateRow(0);
//表頭
for (int hi = 0; hi < dt.Columns.Count; hi++)
{
ICell cell = row.CreateCell(hi);
cell.SetCellValue(dt.Columns[hi].ColumnName);
cell.CellStyle = cellstyle;
}
Sheets.Add(sheet);
};
#endregion
int sheetIndex = 0;
int rowcount = -1;
DataRow lastIRow = null;
try
{
addSheet();
for (int i = 0; i < dt.Rows.Count; i++)
{
rowcount++;
if (rowcount > 65535 * (sheetIndex+1))
{
addSheet();
++sheetIndex;
}
int currentI = rowcount - (sheetIndex * 65535);
IRow row1 = Sheets.ToArray()[sheetIndex].CreateRow(currentI + 1);
if (lastIRow==null)
{
lastIRow = dt.Rows[i];
}
DataRow currentDataRow = dt.Rows[i];
Boolean isend =(i==dt.Rows.Count-1);
if (!isend)
{
var isaddCount = func(lastIRow, currentDataRow, row1, isend);
if (isaddCount)
{
rowcount++;
currentI = rowcount - (sheetIndex * 65535);
row1 = Sheets.ToArray()[sheetIndex].CreateRow(currentI + 1);
}
}
for (int j = 0; j < dt.Columns.Count; j++)
{
ICell cell = row1.CreateCell(j);
string colName = dt.Columns[j].ColumnName;
if (colName.IndexOf("監管碼") > 0 || colName.IndexOf("產品碼") > 0 || colName.IndexOf("中獎用戶") > 0)
{
cell.SetCellValue("'" + dt.Rows[i][j].ToString());
cell.CellStyle = cellstyle;
}
else
{
cell.SetCellValue(dt.Rows[i][j].ToString());
cell.CellStyle = cellstyle;
}
}
if (isend)
{
func(lastIRow, currentDataRow, row1, isend);
}
lastIRow = currentDataRow;
}
//轉爲字節數組
MemoryStream stream = new MemoryStream();
hssfworkbook.Write(stream);
stream.Position = 0;
StreamReader rd = new StreamReader(stream, System.Text.Encoding.BigEndianUnicode);
StringBuilder sb = new StringBuilder();
sb.Append(rd.ReadToEnd());
stream.Close();
hssfworkbook.Close();
StringWriter sw = new StringWriter();
sw.Write(sb.ToString());
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName + ".xls", System.Text.Encoding.UTF8));
HttpContext.Current.Response.ContentType = "application/ms-excel";
System.Web.HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.BigEndianUnicode;
System.Web.HttpContext.Current.Response.Write(sw);
sw.Close();
System.Web.HttpContext.Current.Response.End();
}
catch (Exception ex)
{
hssfworkbook.Close();
Acexe.Common.Utils.Log("error", String.Format("ExportDataToExcel {0}{1}{2}", ex.Message, System.Environment.NewLine, ex.StackTrace));
}
}
3.自定義參考源碼
Func<DataRow, DataRow, IRow,Boolean, Boolean> func = (a, b, c,d) =>
{
ICellStyle cellstyle = c.Sheet.Workbook.CreateCellStyle();//設置垂直居中格式
cellstyle.VerticalAlignment = VerticalAlignment.Top; //垂直居中
cellstyle.Alignment = HorizontalAlignment.Right; //居中
if(d)
{
if (Decimal.TryParse(b["紅包金額"].ToString(), out recordMoney))
{
moneyCount += recordMoney;
}
ICell cell = c.Sheet.CreateRow(c.RowNum+1).CreateCell(0);
cell.SetCellValue("UserId:" + a["UserId"].ToString() + " 彙總: " + moneyCount.ToString("0.00"));
cell.CellStyle = cellstyle;
c.Sheet.AddMergedRegion(new CellRangeAddress(c.RowNum+1, c.RowNum+1, 0, a.Table.Columns.Count - 1));
return true;
}
else
{
if (!(a["UserId"].ToString().Equals(b["UserId"].ToString())))
{
ICell cell = c.CreateCell(0);
cell.SetCellValue("UserId:" + a["UserId"].ToString() + " 彙總: " + moneyCount.ToString("0.00"));
cell.CellStyle = cellstyle;
c.Sheet.AddMergedRegion(new CellRangeAddress(c.RowNum, c.RowNum, 0, a.Table.Columns.Count - 1));
if (Decimal.TryParse(b["紅包金額"].ToString(), out recordMoney))
{
moneyCount = recordMoney;
}
return true;
}
else
{
if (Decimal.TryParse(b["紅包金額"].ToString(), out recordMoney))
{
moneyCount += recordMoney;
}
return false;
}
}
};