开发笔记:使用NPOI进行Excel数据的导入导出

public static void SimpleTableToExcel(DataTable dt, string fileName)
{
IWorkbook workbook;
string fileExt = Path.GetExtension(fileName).ToLower();
if (fileExt == ".xlsx")
{
workbook = new XSSFWorkbook();
}
else if (fileExt == ".xls")
{
workbook = new HSSFWorkbook();
}
else
{
workbook = null;
return;
}
ISheet sheet = string.IsNullOrEmpty(dt.TableName) ? workbook.CreateSheet("Sheet1") : workbook.CreateSheet(dt.TableName);
//表头
IRow row = sheet.CreateRow(0);
for (int i = 0; i )
{
ICell cell = row.CreateCell(i);
cell.SetCellValue(dt.Columns[i].ColumnName);
}
//数据
for (int i = 0; i )
{
IRow row1 = sheet.CreateRow(i + 1);
for (int j = 0; j )
{
ICell cell = row1.CreateCell(j);
cell.SetCellValue(dt.Rows[i][j].ToString());
}
}
//保存为Excel文件
using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
{
workbook.Write(fs);
}
}

public static DataTable ImportFromExcel(string fileName)
{
DataTable dt = new DataTable();
IWorkbook workbook;
string fileExt = Path.GetExtension(fileName).ToLower();
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
//XSSFWorkbook 适用XLSX格式，HSSFWorkbook 适用XLS格式
if (fileExt == ".xlsx")
{
workbook = new XSSFWorkbook(fs);
}
else if (fileExt == ".xls")
{
workbook = new HSSFWorkbook(fs);
}
else
{
workbook = null;
return null;
}
ISheet sheet = workbook.GetSheetAt(0);//Sheet总数量：workbook.NumberOfSheets
//表头
IRow header = sheet.GetRow(sheet.FirstRowNum);
for (int i = 0; i )
{
ICell obj = header.GetCell(i);
if (obj.CellType == CellType.Blank || obj.StringCellValue == string.Empty)
{
dt.Columns.Add(new DataColumn("Columns" + i.ToString()));
}
else
dt.Columns.Add(new DataColumn(obj.ToString()));
}
//数据
for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)
{
DataRow dr = dt.NewRow();
IRow row = sheet.GetRow(i);
for (int j = row.FirstCellNum; j )
{
if (row.GetCell(j) != null)
{
dr[j] = row.GetCell(j);
}
}
dt.Rows.Add(dr);
}
}
return dt;
}

IEnumerator rows = sheet.GetEnumerator();
while (rows.MoveNext())
{
IRow row = (HSSFRow)rows.Current;
ICell cell = row.GetCell(0);
if (cell != null && cell.StringCellValue == "XX")
{
return row.GetCell(1).StringCellValue;
}
}

IWorkbook workbook;
using (FileStream fs = new FileStream("模板文件.xls", FileMode.Open, FileAccess.Read))
{
workbook = new HSSFWorkbook(fs);
}
ISheet cloneSheet = workbook.CloneSheet(workbook.GetSheetIndex("Sheet1"));//复制第一个模板Sheet
cloneSheet.ForceFormulaRecalculation = true;
workbook.SetSheetName(workbook.GetSheetIndex(cloneSheet), "SheetClone");//设置新SheetName
cloneSheet.GetRow(4).GetCell(1).SetCellValue("a");//为已经存在的单元格赋值
IRow row = cloneSheet.GetRow(15);
if (row == null)
row = cloneSheet.CreateRow(15);
ICell cell = row.GetCell(7);
if (cell == null)
cell = row.CreateCell(7);
cell.SetCellValue("XX");// 为不存在的单元格，先新建再赋值
cloneSheet.ShiftRows(51, 60, 34);//51-60行（尾部）整体移动34行，腾出更多控件插入多行数据
workbook.RemoveSheetAt(workbook.GetSheetIndex("Sheet1"));//移除原模板Sheet

FileStream fs_new = new FileStream(DateTime.Now.Ticks + ".xls", FileMode.Create);
workbook.Write(fs_new);
fs_new.Close();

public static MemoryStream ExportToExcel(DataTable dt, string HeaderText)
{
var workbook = new HSSFWorkbook();
ISheet sheet = workbook.CreateSheet(string.IsNullOrWhiteSpace(dt.TableName) ? "Sheet1" : dt.TableName);
//右击文件“属性”信息
#region 文件属性信息
{
var dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "NPOI";
workbook.DocumentSummaryInformation = dsi;
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Author = "文件作者信息";
si.ApplicationName = "创建程序信息";
si.LastAuthor = "最后保存者信息";
si.Comments = "作者信息";
si.Title = "标题信息";
si.Subject = "主题信息";
si.CreateDateTime = DateTime.Now;
workbook.SummaryInformation = si;
}
#endregion
//格式
var dateStyle = workbook.CreateCellStyle();
var format = workbook.CreateDataFormat();
dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");//日期格式
//取得列宽
var arrColWidth = new int[dt.Columns.Count];
foreach (DataColumn item in dt.Columns)
{
arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
}
for (var i = 0; i )
{
for (var j = 0; j )
{
int intTemp = Encoding.GetEncoding(936).GetBytes(dt.Rows[i][j].ToString()).Length;
if (intTemp > arrColWidth[j])
{
arrColWidth[j] = intTemp;
}
}
}
int rowIndex = 0;
foreach (DataRow row in dt.Rows)
{
#region 表头 列头
if (rowIndex == 65535 || rowIndex == 0)
{
if (rowIndex != 0)
{
sheet = workbook.CreateSheet();//超过65535行，则新建一个Sheet
}
#region 表头及样式
{
var headerRow = sheet.CreateRow(0);
headerRow.HeightInPoints = 25;
headerRow.CreateCell(0).SetCellValue(HeaderText);
//CellStyle
ICellStyle headStyle = workbook.CreateCellStyle();
headStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;// 左右居中
headStyle.VerticalAlignment = VerticalAlignment.Center;// 上下居中
// 设置单元格的背景颜色（单元格的样式会覆盖列或行的样式）
headStyle.FillForegroundColor = (short)11;
//定义font
IFont fOnt= workbook.CreateFont();
font.FontHeightInPoints = 20;
font.Boldweight = 700;
headStyle.SetFont(font);
headerRow.GetCell(0).CellStyle = headStyle;
sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dt.Columns.Count - 1));//合并区域
}
#endregion
#region 列头及样式
{
var headerRow = sheet.CreateRow(1);
//CellStyle
ICellStyle headStyle = workbook.CreateCellStyle();
headStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;// 左右居中
headStyle.VerticalAlignment = VerticalAlignment.Center;// 上下居中
//定义font
IFont fOnt= workbook.CreateFont();
font.FontHeightInPoints = 10;
font.Boldweight = 700;
headStyle.SetFont(font);
foreach (DataColumn column in dt.Columns)
{
headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);//设置列宽
}
}
#endregion
rowIndex = 2;//数据行RowIndex为2（表头和列头个占一行）
}
#endregion
#region 内容
var dataRow = sheet.CreateRow(rowIndex);
foreach (DataColumn column in dt.Columns)
{
var newCell = dataRow.CreateCell(column.Ordinal);
string drValue = row[column].ToString();
switch (column.DataType.ToString())
{
case "System.String"://字符串类型
newCell.SetCellValue(drValue);
break;
case "System.DateTime"://日期类型
DateTime dateV;
DateTime.TryParse(drValue, out dateV);
newCell.SetCellValue(dateV);
newCell.CellStyle = dateStyle;//格式化显示
break;
case "System.Boolean"://布尔型
bool boolV = false;
bool.TryParse(drValue, out boolV);
newCell.SetCellValue(boolV);
break;
case "System.Int16"://整型
case "System.Int32":
case "System.Int64":
case "System.Byte":
int intV = 0;
int.TryParse(drValue, out intV);
newCell.SetCellValue(intV);
break;
case "System.Decimal"://浮点型
case "System.Double":
double doubV = 0;
double.TryParse(drValue, out doubV);
newCell.SetCellValue(doubV);
break;
case "System.DBNull"://空值处理
newCell.SetCellValue("");
break;
default:
newCell.SetCellValue("");//设置单元格公式：newCell.SetCellFormula("SUM($B0:$D0)")
break;
}
}
#endregion
rowIndex++;
}
//自动列宽
for (int i = 0; i <= dt.Columns.Count; i++)
sheet.AutoSizeColumn(i, true);
using (MemoryStream ms = new MemoryStream())
{
workbook.Write(ms);
ms.Flush();
ms.Position = 0;
return ms;
}
}

public static void ExportToExcelByWeb(DataTable dt, string HeaderText, string FileName)
{
HttpContext context = HttpContext.Current;
context.Response.ContentType = "application/vnd.ms-excel";
context.Response.ContentEncoding = Encoding.UTF8;
context.Response.Charset = "UTF-8";
context.Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", HttpUtility.UrlEncode(FileName, Encoding.UTF8)));
byte[] data = ExportToExcel(dt, HeaderText).GetBuffer();//Read（）方法也可以
context.Response.BinaryWrite(data);// 或者： context.Response.OutputStream.Write(data,0,data.Length)
context.Response.End();
}

public static void ExportToExcel(DataTable dt, string HeaderText, string FileName)
{
using (MemoryStream ms = ExportToExcel(dt, HeaderText))
{
using (FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write))
{
byte[] data = ms.ToArray();//跟GetBuffer（）对比，速度稍慢，但无空数据
fs.Write(data, 0, data.Length);
fs.Flush();
}
}
}