总结一下工作中遇到的NPOI以及在ASP.NET MVC中的使用

时间:2022-05-24 09:40:04

1.前言

相信大家在工作中经常要遇到一些导入导出Execl操作。学习贵在分享,分享使人快乐,园子里的前辈已经有很多好的文章,鄙人也是能力有限,在这里把这些好的文章总结,方便以后再工作中使用。

NPOI:是 POI 项目的 .NET 版本。POI是一个开源的Java读写Excel、WORD等微软OLE2组件文档的项目。

NPOI是构建在POI 3.x版本之上的,它可以在没有安装Office的情况下对Word/Excel文档进行读写操作。

它不使用Office COM组件(Microsoft.Office.Interop.XXX.dll),不需要安装Microsoft Office,支持对Office 97-2003的文件格式,功能比较强大。

能够读写几乎所有的Office 97-2003文件格式,至少能够支持Word, PowerPoint, Excel, Visio的格式。

NPOI官方网站【点击这里】

1、整个Excel表格叫做工作表:WorkBook(工作薄),包含的叫页(工作表):Sheet;行:Row;单元格Cell。

2、NPOI是POI的C#版本,NPOI的行和列的index都是从0开始

3、POI读取Excel有两种格式一个是HSSF,另一个是XSSF。

HSSF和XSSF的区别如下:

HSSFWorkbook:是操作Excel2003以前(包括2003)的版本,扩展名是.xls

XSSFWorkbook:是操作Excel2007的版本,扩展名是.xlsx

即:HSSF适用2007以前的版本,XSSF适用2007版本及其以上的。

HSSFWorkbook对应的就是Excel文件  工作簿,

HSSFSheet对应的就是Excel中sheet 工作表,

HSSFCell对应的就是Excel的单元格,

HSSFRow对应的就是Excel的行

.NET调用NPOI组件导入导出Excel的操作类

     此NPOI操作类的优点如下:
       (1)支持web及winform从DataTable导出到Excel; 
       (2)生成速度很快; 
       (3)准确判断数据类型,不会出现身份证转数值等问题; 
       (4)如果单页条数大于65535时会新建工作表; 
       (5)列宽自适应;

2.简单用法

namespace 导入导出
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
} private void btnInput_Click(object sender, EventArgs e)
{
#region 导入到DataTable
using (FileStream stream = File.OpenRead("huangjinfeng.xls"))
{
IWorkbook workbook = new HSSFWorkbook(stream);
ISheet sheet = workbook.GetSheet("员工捐款信息表"); DataTable table = new DataTable();
IRow headerRow = sheet.GetRow();
int cellCount = headerRow.LastCellNum;
int rowCount = sheet.LastRowNum; for (int i = headerRow.FirstCellNum; i < cellCount; i++)
{
DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
table.Columns.Add(column);
} for (int i = (sheet.FirstRowNum + ); i <= rowCount; i++)
{
IRow row = sheet.GetRow(i);
DataRow dataRow = table.NewRow(); if (row != null)
{
for (int j = row.FirstCellNum; j < cellCount; j++)
{
if (row.GetCell(j) != null)
dataRow[j] = row.GetCell(j);
}
} table.Rows.Add(dataRow);
} this.dataGridView1.DataSource = table;
MessageBox.Show("导入数据成功");
}
#endregion #region 导入到数据库
//using (FileStream stream = File.OpenRead("huangjinfeng.xls"))
//{
// string sql="INSERT INTO [dbo].[DonationDetail]([dUserName],[dcID],[dAmount],[dDate],[disdelete],[dCreateTime])";
// RenderToDb(stream,sql);
// MessageBox.Show("SQL");
//}
#endregion } private void btnOut_Click(object sender, EventArgs e)
{
DonationEntities2 db = new DonationEntities2();
var lists = db.CreateObjectSet<DonationDetail>().Where(c => c.disdelete == ).ToList(); #region *导出
HSSFWorkbook workbook = new HSSFWorkbook();
//2.创建工作表
ISheet sheet = workbook.CreateSheet("员工捐款信息表");
IRow rowHeader = sheet.CreateRow();
rowHeader.CreateCell(, CellType.String).SetCellValue("DId");
rowHeader.CreateCell(, CellType.String).SetCellValue("员工姓名");
rowHeader.CreateCell(, CellType.String).SetCellValue("DcId");
rowHeader.CreateCell(, CellType.String).SetCellValue("捐款金额");
rowHeader.CreateCell(, CellType.String).SetCellValue("捐款日期");
rowHeader.CreateCell(, CellType.String).SetCellValue("是否删除");
rowHeader.CreateCell(, CellType.String).SetCellValue("创建日期"); for (int i = ; i < lists.Count; i++)
{
IRow row = sheet.CreateRow(i + );
//为指定的行添加列
row.CreateCell(, CellType.String).SetCellValue(lists[i].dId);
row.CreateCell(, CellType.String).SetCellValue(lists[i].dUserName);
row.CreateCell(, CellType.String).SetCellValue(lists[i].dcID);
row.CreateCell(, CellType.String).SetCellValue(lists[i].dAmount.ToString());
row.CreateCell(, CellType.String).SetCellValue(Convert.ToDateTime(lists[i].dDate.ToString()));
row.CreateCell(, CellType.String).SetCellValue(lists[i].disdelete);
row.CreateCell(, CellType.String).SetCellValue(Convert.ToDateTime(lists[i].dCreateTime.ToString()));
} //使用文件流做数据的写入
using (FileStream fss = new FileStream("huangjinfeng.xls", FileMode.Create))
{
workbook.Write(fss);
}
MessageBox.Show("导出数据成功");
#endregion
}
        #region 导入到数据库
public static void RenderToDb(Stream excelFileStream, string insertSql)
{
using (excelFileStream)
{
IWorkbook workbook = new HSSFWorkbook(excelFileStream);
ISheet sheet = workbook.GetSheetAt();//取第一个工作表
StringBuilder builder = new StringBuilder(); IRow headerRow = sheet.GetRow();//第一行为标题行
int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1 for (int i = (sheet.FirstRowNum + ); i <= rowCount; i++)
{
IRow row = sheet.GetRow(i);
if (row != null)
{
builder.Append(insertSql);
builder.Append(" values (");
for (int j = row.FirstCellNum; j < cellCount; j++)
{
builder.AppendFormat("'{0}',", row.GetCell(j)).Replace("'", "''");
}
builder.Length = builder.Length - ;
builder.Append(");");
} if ((i % == || i == rowCount) && builder.Length > )
{
//每50条记录一次批量插入到数据库
//rowAffected += dbAction(builder.ToString());
SqlHelper.ExecuteNonQuery(builder.ToString());
builder.Length = ;
}
}
}
}
#endregion

RenderToDb(Stream excelFileStream, string insertSql)

        #region 是否有数据
/// <summary>
/// 是否有数据
/// </summary>
/// <param name="excelFileStream"></param>
/// <returns></returns>
public static bool HasData(Stream excelFileStream)
{
using (excelFileStream)
{
IWorkbook workbook = new HSSFWorkbook(excelFileStream);
if (workbook.NumberOfSheets > )
{
ISheet sheet = workbook.GetSheetAt();
return sheet.PhysicalNumberOfRows > ;
}
}
return false;
}
#endregion

HasData(Stream excelFileStream)

    }
}

3.项目中的Execl导入导出

工作中我一般主要是用到的MVC,在这里就说说我们项目中一般的处理过程。先看看我自己写的一个NPOIBase父类。

    public class NPOIBase : ActionResult
{
public IWorkbook _workbook { get; set; }
public ISheet _sheet { get; set; }
public ICellStyle _titleStyle { get; set; }
public ICellStyle _leftStyle { get; set; }
public ICellStyle _centerStyle { get; set; }
public ICellStyle _rightStyle { get; set; }
public ICellStyle _headStyle { get; set; }
public ICellStyle _leftborderStyle { get; set; }
public ICellStyle _rightborderStyle { get; set; }
public ICellStyle _noneRightBorderStyle { get; set; }
public ICellStyle _noneLeftBorderStyle { get; set; }
public ICellStyle _noneLeftAndRightBorderStyle { get; set; }
public ICellStyle _borderStyle { get; set; }
public override void ExecuteResult(ControllerContext context)
{
}
public void IniNPOI(bool isHeadBorder = false, string sheetName = "")
{
_workbook = new HSSFWorkbook();
_sheet = string.IsNullOrWhiteSpace(sheetName) ? _workbook.CreateSheet() : _workbook.CreateSheet(sheetName);
IniStyle(isHeadBorder);
}
public void IniStyle(bool isHeadBorder = false)
{
IFont font12 = _workbook.CreateFont();
font12.FontHeightInPoints = ;
font12.Boldweight = ; _titleStyle = _workbook.CreateCellStyle();
_titleStyle.Alignment = HorizontalAlignment.Center;
_titleStyle.VerticalAlignment = VerticalAlignment.Top;
_titleStyle.SetFont(font12); _leftStyle = _workbook.CreateCellStyle();
_leftStyle.Alignment = HorizontalAlignment.Left;
_leftStyle.VerticalAlignment = VerticalAlignment.Top; _centerStyle = _workbook.CreateCellStyle();
_centerStyle.Alignment = HorizontalAlignment.Center;
_centerStyle.VerticalAlignment = VerticalAlignment.Top; _rightStyle = _workbook.CreateCellStyle();
_rightStyle.Alignment = HorizontalAlignment.Right;
_rightStyle.VerticalAlignment = VerticalAlignment.Top; _headStyle = _workbook.CreateCellStyle();
_headStyle.Alignment = HorizontalAlignment.Center;
_headStyle.VerticalAlignment = VerticalAlignment.Top;
if (isHeadBorder)
{
_headStyle.BorderBottom = BorderStyle.Thin;
_headStyle.BorderLeft = BorderStyle.Thin;
_headStyle.BorderRight = BorderStyle.Thin;
_headStyle.BorderTop = BorderStyle.Thin;
}
_leftborderStyle = _workbook.CreateCellStyle();
_leftborderStyle.Alignment = HorizontalAlignment.Left;
_leftborderStyle.VerticalAlignment = VerticalAlignment.Top;
_leftborderStyle.BorderBottom = BorderStyle.Thin;
_leftborderStyle.BorderLeft = BorderStyle.Thin;
_leftborderStyle.BorderRight = BorderStyle.Thin;
_leftborderStyle.BorderTop = BorderStyle.Thin; _rightborderStyle = _workbook.CreateCellStyle();
_rightborderStyle.Alignment = HorizontalAlignment.Right;
_rightborderStyle.VerticalAlignment = VerticalAlignment.Top;
_rightborderStyle.BorderBottom = BorderStyle.Thin;
_rightborderStyle.BorderLeft = BorderStyle.Thin;
_rightborderStyle.BorderRight = BorderStyle.Thin;
_rightborderStyle.BorderTop = BorderStyle.Thin; _noneRightBorderStyle = _workbook.CreateCellStyle();
_noneRightBorderStyle.Alignment = HorizontalAlignment.Left;
_noneRightBorderStyle.VerticalAlignment = VerticalAlignment.Top;
_noneRightBorderStyle.BorderBottom = BorderStyle.Thin;
_noneRightBorderStyle.BorderLeft = BorderStyle.Thin;
_noneRightBorderStyle.BorderTop = BorderStyle.Thin; _noneLeftBorderStyle = _workbook.CreateCellStyle();
_noneLeftBorderStyle.Alignment = HorizontalAlignment.Right;
_noneLeftBorderStyle.VerticalAlignment = VerticalAlignment.Top;
_noneLeftBorderStyle.BorderBottom = BorderStyle.Thin;
_noneLeftBorderStyle.BorderRight = BorderStyle.Thin;
_noneLeftBorderStyle.BorderTop = BorderStyle.Thin; _noneLeftAndRightBorderStyle = _workbook.CreateCellStyle();
_noneLeftAndRightBorderStyle.Alignment = HorizontalAlignment.Center;
_noneLeftAndRightBorderStyle.VerticalAlignment = VerticalAlignment.Top;
_noneLeftAndRightBorderStyle.BorderBottom = BorderStyle.Thin;
_noneLeftAndRightBorderStyle.BorderTop = BorderStyle.Thin; _borderStyle = _workbook.CreateCellStyle();
_borderStyle.Alignment = HorizontalAlignment.Center;
_borderStyle.VerticalAlignment = VerticalAlignment.Top;
_borderStyle.BorderBottom = BorderStyle.Thin;
_borderStyle.BorderLeft = BorderStyle.Thin;
_borderStyle.BorderRight = BorderStyle.Thin;
_borderStyle.BorderTop = BorderStyle.Thin; IFont font = _workbook.CreateFont();
font.FontHeightInPoints = ;
font.Boldweight = ;
_headStyle.SetFont(font);
}

IniStyle

        public void FillHeadCell(IRow row, int colIndex, string value, ICellStyle cellStyle = null, 
NPOI.SS.Util.CellRangeAddress mergedCellRangeAddress = null)
{
if (_sheet == null || row == null) return;
if (cellStyle == null) cellStyle = _headStyle;
FillCell(row, colIndex, value, cellStyle, mergedCellRangeAddress);
_sheet.SetColumnWidth(colIndex, (Encoding.Default.GetBytes(value.Trim()).Length + ) * );
}
public void FillCell(IRow row, int colIndex, string value, ICellStyle cellStyle = null,
NPOI.SS.Util.CellRangeAddress mergedCellRangeAddress = null)
{
if (_sheet == null || row == null) return;
ICell titleSum = row.CreateCell(colIndex);
titleSum.SetCellValue(value);
if (cellStyle != null) titleSum.CellStyle = cellStyle;
else if (_centerStyle != null) titleSum.CellStyle = _centerStyle;
if (mergedCellRangeAddress != null) _sheet.AddMergedRegion(mergedCellRangeAddress);
}
public void FillCell(IRow row, int colIndex, double value, ICellStyle cellStyle = null,
NPOI.SS.Util.CellRangeAddress mergedCellRangeAddress = null)
{
if (_sheet == null || row == null) return;
ICell titleSum = row.CreateCell(colIndex);
titleSum.SetCellValue(value);
if (cellStyle != null) titleSum.CellStyle = cellStyle;
else if (_centerStyle != null) titleSum.CellStyle = _centerStyle;
if (mergedCellRangeAddress != null) _sheet.AddMergedRegion(mergedCellRangeAddress);
}
public void ResponseOutPutExcelStream(string fildName)
{
if (string.IsNullOrWhiteSpace(fildName)) fildName = DateTime.Now.ToString("yyyyMMddHHmmss.xls");
if (fildName.ToLower().IndexOf(".xls") == -) fildName += ".xls";
HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
HttpContext.Current.Response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", fildName));
HttpContext.Current.Response.Clear(); MemoryStream file = new MemoryStream();
_workbook.Write(file);
file.WriteTo(HttpContext.Current.Response.OutputStream);
HttpContext.Current.Response.End();
}
public void SetPrint(bool isLandscape = false, bool isFitToPage = false, double topMargin = , double rightMargin = ,
double bottomMargin = 0.5, double leftMargin = , short scale = )
{
_sheet.PrintSetup.Landscape = isLandscape;
_sheet.SetMargin(MarginType.TopMargin, topMargin);
_sheet.SetMargin(MarginType.RightMargin, rightMargin);
_sheet.SetMargin(MarginType.LeftMargin, leftMargin);
_sheet.SetMargin(MarginType.BottomMargin, bottomMargin);
_sheet.PrintSetup.PaperSize = ;
_sheet.PrintSetup.Scale = scale;
_sheet.FitToPage = isFitToPage;
if (isFitToPage)
{
_sheet.PrintSetup.FitWidth = ;
_sheet.PrintSetup.FitHeight = ;
}
}
}

这个由于父类是继承的ActionResult,我们用起来就比较方便,在Action中,直接使用就可以了。代码示例如下...

    public class BaseMaterialsExcelResult : NPOIBase
{ string[] __headers = null;
IList<BaseMaterials> __BaseMaterialsList;
public BaseMaterialsExcelResult(IList<BaseMaterials> BaseMaterialsList)
{
__BaseMaterialsList = BaseMaterialsList;
__headers = new string[] {
"序号",
"材料",
"型号",
"推荐供应商",
"出库数量",
"入库数量",
"结存"
};
}
public override void ExecuteResult(ControllerContext context)
{
if (__BaseMaterialsList == null || __BaseMaterialsList.Count() == ) return;
IniNPOI();
int rowIndex = ;
foreach (var item in __BaseMaterialsList)
{
#region 新建表,填充列头,样式
int colIndex = ;
if (rowIndex == || rowIndex == )
{
if (rowIndex != )
_sheet = _workbook.CreateSheet();
IRow headerRow = _sheet.CreateRow(rowIndex);
foreach (var head in __headers)
FillHeadCell(headerRow, colIndex++, head);
rowIndex = ;
}
#endregion #region 填充内容
IRow dataRow = _sheet.CreateRow(rowIndex);
colIndex = ;
FillCell(dataRow, colIndex++, rowIndex);
FillCell(dataRow, colIndex++, item.Name);
FillCell(dataRow, colIndex++, item.Type);
FillCell(dataRow, colIndex++, item.ProviderName);
FillCell(dataRow, colIndex++, item.OutStorageCount.ToString());
FillCell(dataRow, colIndex++, item.StorageCount.ToString());
FillCell(dataRow, colIndex++, item.StockCount.ToString());
#endregion rowIndex++;
} _sheet.CreateFreezePane(, , , );
ResponseOutPutExcelStream("BaseMaterials.xls");
} }

控制器中的代码如下:

    public class HomeController : Controller
{
BluedonStockEntities db = new BluedonStockEntities(); public List<BaseMaterials> GetList()
{
return db.CreateObjectSet<BaseMaterials>().Where(c => true).ToList();
} public ActionResult Index()
{
var list = GetList();
return View(list);
} public ActionResult Execl()
{
var list = GetList();
return new BaseMaterialsExcelResult(list); } }

4.问题总结。

  1. 在实例化了一个WorkBook之后,最好添加一个sheet,虽然在最新版的Npoi.net中自动添加了,但是遇到迁移到原来版本就会出现问题。所以我建议还是最少添加一个sheet
  2. 在从单元格取值时要注意单元格的类型,一定要用对应的类型的方法来取单元格中的对应类型的值,如果不确定,那只能是强制转换成为string类型,毕竟string类型是excel中其他类型都可以转换过来的
  3. 在获取sheet中的某一行或者某一行的某一个单元格的时候,还要注意就是一定要确保创建了该行,并且取单元格还要确保创建了单元格,否则会报Null reference not to object 这个我们经常会看到的异常信息。在外层一定要加上try捕获异常
  4. 合并单元格是sheet的工作,因此需要获取对应的sheet,然后调用其AddMergedRegion方法合并单元格,在合并单元格的时候,我们不需要确保该单元格已经存在或创建。
  5. 在为单元格设置样式的过程中,我们会发现所有和样式相关的类的创建都是通过workBook.Create(Font)..这种方式来执行的,我们不可以直接new一个类的实例。
  6. 如果前面的工作都已经做好,需要把内存中的excel表写到硬盘上时,需要调用workBook.write()方法,传入一个文件流进行创建。在这里有可能会出现一个问题,就是你要创建的文件你已经打开了,这时程序就会出现异常,因此我们在调试程序的时候一定要记得打开了excel文件以后要关闭
  7. 最后需要注意的就是文件流,在我们把excel写到硬盘上以后,要显式的调用其close()方法关闭文件流。因为如果不关闭文件流的话,以后就会出现无法重新创建该文件的错误,并且会提示 某文件正由另一进程使用,因此该进程无法访问此文件。

简单用法的源码【点击下载】

MVC版的源码【点击下载】

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