如何使用.NET操作Excel组件NPOI？
很多的软件项目几乎都包含着对文档的操作，前面已经介绍过两款操作文档的组件，现在介绍一款文档操作的组件NPOI。
NPOI可以生成没有安装在您的服务器上的Microsoft Office套件的Excel报表，并且在后台调用Microsoft Excel ActiveX更有效率;从Office文档中提取文本，以帮助您实现全文索引功能（大多数时候，此功能用于创建搜索引擎）； 从Office文档提取图像； 生成包含公式的Excel工作表。
一.NPOI组件概述：
NPOI是完全免费使用； 涵盖Excel的大多数功能（单元格样式，数据格式，公式等）；支持xls，xlsx，docx；设计为面向接口（看看NPOI.SS命名空间）；支持不仅导出而且导入； .Net 2.0甚至为xlsx和docx（虽然我们也支持.NET 4.0）； 来自世界各地的成功案例；巨大的基本例子；对隔离存储没有依赖。
以上是NPOI的优点，其他一些优点可以不用太在意，估计很多人对“支持xls，xlsx，docx”这一特点感觉有些惊讶，因为在很多人的印象里面NPOI就是对Excel进行相关的操作，但是在这里突然看到了对docx也可以操作，这一特点可能让很多人感到欣喜，因为NPOI的的确确是一个很不错的组件，用过的人都说好，我也不例外。
NPOI的运行要求：VS2010与.NET 4.0运行时；VS2005或VS2008与.NET 2.0运行时（SP1）；vs2003与.NET 1.1；Mono；ASP.NET中的中等信任环境。
二.NPOI核心类和方法解析：
以上是对NPOI的相关背景和使用环境做了一个简单的介绍，接下来我具体的看一下NPOI的一些核心类和方法，由于下载的是DLL文件，还是采用.NET Reflector对DLL文件进行反编译，以此查看源代码。
如果需要具体的了解NPOI可以直接访问：http://npoi.codeplex.com/SourceControl/latest，提供了NPOI的源码和一些demo，由于本溪介绍的重点是NPOI对Excel的操作，所以下面的类和实例主要是对操作Excel的介绍，如果需要对docx的操作，可以具体查看相应的类demo。
1.XSSFWorkbook类CreateSheet():创建表。
public ISheet CreateSheet(string sheetname)
{
if (sheetname == null)
{
throw new ArgumentException("sheetName must not be null");
}
if (this.ContainsSheet(sheetname, this.sheets.Count))
{
throw new ArgumentException("The workbook already contains a sheet of this name");
}
if (sheetname.Length > 0x1f)
{
sheetname = sheetname.Substring(0, 0x1f);
}
WorkbookUtil.ValidateSheetName(sheetname);
CT_Sheet sheet = this.AddSheet(sheetname);
int index = 1;
foreach (XSSFSheet sheet2 in this.sheets)
{
index = (int) Math.Max((long) (sheet2.sheet.sheetId + 1), (long) index);
}
Label_0099:
foreach (XSSFSheet sheet3 in this.sheets)
{
index = (int) Math.Max((long) (sheet3.sheet.sheetId + 1), (long) index);
}
string fileName = XSSFRelation.WORKSHEET.GetFileName(index);
foreach (POIXMLDocumentPart part in base.GetRelations())
{
if ((part.GetPackagePart() != null) && fileName.Equals(part.GetPackagePart().PartName.Name))
{
index++;
goto Label_0099;
}
}
XSSFSheet item = (XSSFSheet) base.CreateRelationship(XSSFRelation.WORKSHEET, XSSFFactory.GetInstance(), index);
item.sheet = sheet;
sheet.id = item.GetPackageRelationship().Id;
sheet.sheetId = (uint) index;
if (this.sheets.Count == 0)
{
item.IsSelected = true;
}
this.sheets.Add(item);
return item;
}
2.XSSFSheet类Write():将文件流写入到excel。
internal virtual void Write(Stream stream)
{
bool flag = false;
if (this.worksheet.sizeOfColsArray() == 1)
{
CT_Cols colsArray = this.worksheet.GetColsArray(0);
if (colsArray.sizeOfColArray() == 0)
{
flag = true;
this.worksheet.SetColsArray(null);
}
else
{
this.SetColWidthAttribute(colsArray);
}
}
if (this.hyperlinks.Count > 0)
{
if (this.worksheet.hyperlinks == null)
{
this.worksheet.AddNewHyperlinks();
}
CT_Hyperlink[] array = new CT_Hyperlink[this.hyperlinks.Count];
for (int i = 0; i < array.Length; i++)
{
XSSFHyperlink hyperlink = this.hyperlinks[i];
hyperlink.GenerateRelationIfNeeded(base.GetPackagePart());
array[i] = hyperlink.GetCTHyperlink();
}
this.worksheet.hyperlinks.SetHyperlinkArray(array);
}
foreach (XSSFRow row in this._rows.Values)
{
row.OnDocumentWrite();
}
Dictionary<string, string> dictionary = new Dictionary<string, string>();
dictionary[ST_RelationshipId.NamespaceURI] = "r";
new WorksheetDocument(this.worksheet).Save(stream);
if (flag)
{
this.worksheet.AddNewCols();
}
}
3.XSSFSheet类CreateRow()：创建行。
public virtual IRow CreateRow(int rownum)
{
CT_Row cTRow;
XSSFRow row2 = this._rows.ContainsKey(rownum) ? this._rows[rownum] : null;
if (row2 != null)
{
cTRow = row2.GetCTRow();
cTRow.Set(new CT_Row());
}
else if ((this._rows.Count == 0) || (rownum > this.GetLastKey(this._rows.Keys)))
{
cTRow = this.worksheet.sheetData.AddNewRow();
}
else
{
int count = this.HeadMap(this._rows, rownum).Count;
cTRow = this.worksheet.sheetData.InsertNewRow(count);
}
XSSFRow row3 = new XSSFRow(cTRow, this) {
RowNum = rownum
};
this._rows[rownum] = row3;
return row3;
}
4.XSSFWorkbook类GetSheet：获取表。
public ISheet GetSheet(string name)
{
foreach (XSSFSheet sheet in this.sheets)
{
if (name.Equals(sheet.SheetName, StringComparison.InvariantCultureIgnoreCase))
{
return sheet;
}
}
return null;
}
5.WorkbookFactory类：
public class PropertySetFactory
{
public static PropertySet Create(DirectoryEntry dir, string name);
public static PropertySet Create(Stream stream);
public static SummaryInformation CreateSummaryInformation();
public static DocumentSummaryInformation CreateDocumentSummaryInformation();
}
6.DocumentSummaryInformation：
[Serializable]
public class DocumentSummaryInformation : SpecialPropertySet
{
// Fields
public const string DEFAULT_STREAM_NAME = "\x0005DocumentSummaryInformation";
// Methods
public DocumentSummaryInformation(PropertySet ps);
private void EnsureSection2();
public void RemoveByteCount();
public void RemoveCategory();
public void RemoveCompany();
public void RemoveCustomProperties();
public void RemoveDocparts();
public void RemoveHeadingPair();
public void RemoveHiddenCount();
public void RemoveLineCount();
public void RemoveLinksDirty();
public void RemoveManager();
public void RemoveMMClipCount();
public void RemoveNoteCount();
public void RemoveParCount();
public void RemovePresentationFormat();
public void RemoveScale();
public void RemoveSlideCount();
// Properties
public int ByteCount { get; set; }
public string Category { get; set; }
public string Company { get; set; }
public CustomProperties CustomProperties { get; set; }
public byte[] Docparts { get; set; }
public byte[] HeadingPair { get; set; }
public int HiddenCount { get; set; }
public int LineCount { get; set; }
public bool LinksDirty { get; set; }
public string Manager { get; set; }
public int MMClipCount { get; set; }
public int NoteCount { get; set; }
public int ParCount { get; set; }
public string PresentationFormat { get; set; }
public override PropertyIDMap PropertySetIDMap { get; }
public bool Scale { get; set; }
public int SlideCount { get; set; }
}
具体方法：
private void EnsureSection2()
{
if (this.SectionCount < 2)
{
MutableSection section = new MutableSection();
section.SetFormatID(SectionIDMap.DOCUMENT_SUMMARY_INFORMATION_ID2);
this.AddSection(section);
}
}
以上只是对部分的类和方法做了简单的说明，需要了解更多的内容，可以进入官网下载源码，或者使用软件查看DLL文件。
三.NPOI操作实例：
1.枚举(Excel单元格数据类型)：
/// <summary>
/// 枚举(Excel单元格数据类型)
/// </summary>
public enum NpoiDataType
{
/// <summary>
/// 字符串类型-值为1
/// </summary>
String,
/// <summary>
/// 布尔类型-值为2
/// </summary>
Bool,
/// <summary>
/// 时间类型-值为3
/// </summary>
Datetime,
/// <summary>
/// 数字类型-值为4
/// </summary>
Numeric,
/// <summary>
/// 复杂文本类型-值为5
/// </summary>
Richtext,
/// <summary>
/// 空白
/// </summary>
Blank,
/// <summary>
/// 错误
/// </summary>
Error
}
2. 将DataTable数据导入到excel中：
/// <summary>
/// 将DataTable数据导入到excel中
/// </summary>
/// <param name="data">要导入的数据</param>
/// <param name="isColumnWritten">DataTable的列名是否要导入</param>
/// <param name="sheetName">要导入的excel的sheet的名称</param>
/// <param name="fileName">文件夹路径</param>
/// <returns>导入数据行数(包含列名那一行)</returns>
public static int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten, string fileName)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (string.IsNullOrEmpty(sheetName))
{
throw new ArgumentNullException(sheetName);
}
if (string.IsNullOrEmpty(fileName))
{
throw new ArgumentNullException(fileName);
}
IWorkbook workbook = null;
if (fileName.IndexOf(".xlsx", StringComparison.Ordinal) > 0)
{
workbook = new XSSFWorkbook();
}
else if (fileName.IndexOf(".xls", StringComparison.Ordinal) > 0)
{
workbook = new HSSFWorkbook();
}
FileStream fs = null;
try
{
fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
ISheet sheet;
if (workbook != null)
{
sheet = workbook.CreateSheet(sheetName);
}
else
{
return -1;
}
int j;
int count;
//写入DataTable的列名，写入单元格中
if (isColumnWritten)
{
var row = sheet.CreateRow(0);
for (j = 0; j < data.Columns.Count; ++j)
{
row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
}
count = 1;
}
else
{
count = 0;
}
//遍历循环datatable具体数据项
int i;
for (i = 0; i < data.Rows.Count; ++i)
{
var row = sheet.CreateRow(count);
for (j = 0; j < data.Columns.Count; ++j)
{
row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
}
++count;
}
//将文件流写入到excel
workbook.Write(fs);
return count;
}
catch (IOException ioex)
{
throw new IOException(ioex.Message);
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
finally
{
if (fs != null)
{
fs.Close();
}
}
}
3.将excel中的数据导入到DataTable中：
/// <summary>
/// 将excel中的数据导入到DataTable中
/// </summary>
/// <param name="sheetName">excel工作薄sheet的名称</param>
/// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
/// <param name="fileName">文件路径</param>
/// <returns>返回的DataTable</returns>
public static DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn, string fileName)
{
if (string.IsNullOrEmpty(sheetName))
{
throw new ArgumentNullException(sheetName);
}
if (string.IsNullOrEmpty(fileName))
{
throw new ArgumentNullException(fileName);
}
var data = new DataTable();
IWorkbook workbook = null;
FileStream fs = null;
try
{
fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
if (fileName.IndexOf(".xlsx", StringComparison.Ordinal) > 0)
{
workbook = new XSSFWorkbook(fs);
}
else if (fileName.IndexOf(".xls", StringComparison.Ordinal) > 0)
{
workbook = new HSSFWorkbook(fs);
}
ISheet sheet = null;
if (workbook != null)
{
//如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet
sheet = workbook.GetSheet(sheetName) ?? workbook.GetSheetAt(0);
}
if (sheet == null) return data;
var firstRow = sheet.GetRow(0);
//一行最后一个cell的编号 即总的列数
int cellCount = firstRow.LastCellNum;
int startRow;
if (isFirstRowColumn)
{
for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
{
var cell = firstRow.GetCell(i);
var cellValue = cell.StringCellValue;
if (cellValue == null) continue;
var column = new DataColumn(cellValue);
data.Columns.Add(column);
}
startRow = sheet.FirstRowNum + 1;
}
else
{
startRow = sheet.FirstRowNum;
}
//最后一列的标号
var rowCount = sheet.LastRowNum;
for (var i = startRow; i <= rowCount; ++i)
{
var row = sheet.GetRow(i);
//没有数据的行默认是null
if (row == null) continue;
var dataRow = data.NewRow();
for (int j = row.FirstCellNum; j < cellCount; ++j)
{
//同理，没有数据的单元格都默认是null
if (row.GetCell(j) != null)
dataRow[j] = row.GetCell(j).ToString();
}
data.Rows.Add(dataRow);
}
return data;
}
catch (IOException ioex)
{
throw new IOException(ioex.Message);
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
finally
{
if (fs != null)
{
fs.Close();
}
}
}
4.读取Excel文件内容转换为DataSet：
/// <summary>
/// 读取Excel文件内容转换为DataSet,列名依次为 "c0"……c[columnlength-1]
/// </summary>
/// <param name="fileName">文件绝对路径</param>
/// <param name="startRow">数据开始行数(1为第一行)</param>
/// <param name="columnDataType">每列的数据类型</param>
/// <returns></returns>
public static DataSet ReadExcel(string fileName, int startRow, params NpoiDataType[] columnDataType)
{
var ds = new DataSet("ds");
var dt = new DataTable("dt");
var sb = new StringBuilder();
using (var stream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
//使用接口，自动识别excel2003/2007格式
var workbook = WorkbookFactory.Create(stream);
//得到里面第一个sheet
var sheet = workbook.GetSheetAt(0);
int j;
IRow row;
//ColumnDataType赋值
if (columnDataType.Length <= 0)
{
//得到第i行
row = sheet.GetRow(startRow - 1);
columnDataType = new NpoiDataType[row.LastCellNum];
for (var i = 0; i < row.LastCellNum; i++)
{
var hs = row.GetCell(i);
columnDataType[i] = GetCellDataType(hs);
}
}
for (j = 0; j < columnDataType.Length; j++)
{
var tp = GetDataTableType(columnDataType[j]);
dt.Columns.Add("c" + j, tp);
}
for (var i = startRow - 1; i <= sheet.PhysicalNumberOfRows; i++)
{
//得到第i行
row = sheet.GetRow(i);
if (row == null) continue;
try
{
var dr = dt.NewRow();
for (j = 0; j < columnDataType.Length; j++)
{
dr["c" + j] = GetCellData(columnDataType[j], row, j);
}
dt.Rows.Add(dr);
}
catch (Exception er)
{
sb.Append(string.Format("第{0}行出错：{1}\r\n", i + 1, er.Message));
}
}
ds.Tables.Add(dt);
}
if (ds.Tables[0].Rows.Count == 0 && sb.ToString() != "") throw new Exception(sb.ToString());
return ds;
}
5.从DataSet导出到2003：
/// <summary>
/// 从DataSet导出到MemoryStream流2003
/// </summary>
/// <param name="saveFileName">文件保存路径</param>
/// <param name="sheetName">Excel文件中的Sheet名称</param>
/// <param name="ds">存储数据的DataSet</param>
/// <param name="startRow">从哪一行开始写入，从0开始</param>
/// <param name="datatypes">DataSet中的各列对应的数据类型</param>
public static bool CreateExcel2003(string saveFileName, string sheetName, DataSet ds, int startRow, params NpoiDataType[] datatypes)
{
try
{
if (startRow < 0) startRow = 0;
var wb = new HSSFWorkbook();
var dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "pkm";
var si = PropertySetFactory.CreateSummaryInformation();
si.Title =
si.Subject = "automatic genereted document";
si.Author = "pkm";
wb.DocumentSummaryInformation = dsi;
wb.SummaryInformation = si;
var sheet = wb.CreateSheet(sheetName);
//sheet.SetColumnWidth(0, 50 * 256);
//sheet.SetColumnWidth(1, 100 * 256);
ICell cell;
int j;
var maxLength = 0;
var curLength = 0;
object columnValue;
var dt = ds.Tables[0];
if (datatypes.Length < dt.Columns.Count)
{
datatypes = new NpoiDataType[dt.Columns.Count];
for (var i = 0; i < dt.Columns.Count; i++)
{
var dtcolumntype = dt.Columns[i].DataType.Name.ToLower();
switch (dtcolumntype)
{
case "string":
datatypes[i] = NpoiDataType.String;
break;
case "datetime":
datatypes[i] = NpoiDataType.Datetime;
break;
case "boolean":
datatypes[i] = NpoiDataType.Bool;
break;
case "double":
datatypes[i] = NpoiDataType.Numeric;
break;
default:
datatypes[i] = NpoiDataType.String;
break;
}
}
}
// 创建表头
var row = sheet.CreateRow(0);
//样式
var style1 = wb.CreateCellStyle();
//字体
var font1 = wb.CreateFont();
//字体颜色
font1.Color = HSSFColor.White.Index;
//字体加粗样式
font1.Boldweight = (short)FontBoldWeight.Bold;
//style1.FillBackgroundColor = HSSFColor.WHITE.index;
style1.FillForegroundColor = HSSFColor.Green.Index;
//GetXLColour(wb, LevelOneColor);// 设置图案色
//GetXLColour(wb, LevelOneColor);// 设置背景色
style1.FillPattern = FillPattern.SolidForeground;
//样式里的字体设置具体的字体样式
style1.SetFont(font1);
//文字水平对齐方式
style1.Alignment = HorizontalAlignment.Center;
//文字垂直对齐方式
style1.VerticalAlignment = VerticalAlignment.Center;
row.HeightInPoints = 25;
for (j = 0; j < dt.Columns.Count; j++)
{
columnValue = dt.Columns[j].ColumnName;
curLength = Encoding.Default.GetByteCount(columnValue.ToString());
maxLength = (maxLength < curLength ? curLength : maxLength);
var colounwidth = 256 * maxLength;
sheet.SetColumnWidth(j, colounwidth);
try
{
//创建第0行的第j列
cell = row.CreateCell(j);
//单元格式设置样式
cell.CellStyle = style1;
try
{
cell.SetCellType(CellType.String);
cell.SetCellValue(columnValue.ToString());
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
// 创建每一行
for (var i = startRow; i < ds.Tables[0].Rows.Count; i++)
{
var dr = ds.Tables[0].Rows[i];
//创建第i行
row = sheet.CreateRow(i + 1);
for (j = 0; j < dt.Columns.Count; j++)
{
columnValue = dr[j];
curLength = Encoding.Default.GetByteCount(columnValue.ToString());
maxLength = (maxLength < curLength ? curLength : maxLength);
var colounwidth = 256 * maxLength;
sheet.SetColumnWidth(j, colounwidth);
try
{
//创建第i行的第j列
cell = row.CreateCell(j);
// 插入第j列的数据
try
{
var dtype = datatypes[j];
switch (dtype)
{
case NpoiDataType.String:
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(columnValue.ToString());
}
break;
case NpoiDataType.Datetime:
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(columnValue.ToString());
}
break;
case NpoiDataType.Numeric:
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(Convert.ToDouble(columnValue));
}
break;
case NpoiDataType.Bool:
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(Convert.ToBoolean(columnValue));
}
break;
case NpoiDataType.Richtext:
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(columnValue.ToString());
}
break;
}
}
catch (Exception ex)
{
cell.SetCellType(CellType.Numeric);
cell.SetCellValue(columnValue.ToString());
throw new Exception(ex.Message);
}
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
}
//生成文件在服务器上
using (var fs = new FileStream(saveFileName, FileMode.OpenOrCreate, FileAccess.Write))
{
wb.Write(fs);
}
return true;
}
catch (Exception er)
{
throw new Exception(er.Message);
}
}
6.从DataSet导出到MemoryStream流2007：
/// <summary>
/// 从DataSet导出到MemoryStream流2007
/// </summary>
/// <param name="saveFileName">文件保存路径</param>
/// <param name="sheetName">Excel文件中的Sheet名称</param>
/// <param name="ds">存储数据的DataSet</param>
/// <param name="startRow">从哪一行开始写入，从0开始</param>
/// <param name="datatypes">DataSet中的各列对应的数据类型</param>
public static bool CreateExcel2007(string saveFileName, string sheetName, DataSet ds, int startRow, params NpoiDataType[] datatypes)
{
try
{
if (startRow < 0) startRow = 0;
var wb = new XSSFWorkbook();
var sheet = wb.CreateSheet(sheetName);
ICell cell;
int j;
var maxLength = 0;
int curLength;
object columnValue;
var dt = ds.Tables[0];
if (datatypes.Length < dt.Columns.Count)
{
datatypes = new NpoiDataType[dt.Columns.Count];
for (var i = 0; i < dt.Columns.Count; i++)
{
var dtcolumntype = dt.Columns[i].DataType.Name.ToLower();
switch (dtcolumntype)
{
case "string":
datatypes[i] = NpoiDataType.String;
break;
case "datetime":
datatypes[i] = NpoiDataType.Datetime;
break;
case "boolean":
datatypes[i] = NpoiDataType.Bool;
break;
case "double":
datatypes[i] = NpoiDataType.Numeric;
break;
default:
datatypes[i] = NpoiDataType.String;
break;
}
}
}
//创建表头
var row = sheet.CreateRow(0);
//样式
var style1 = wb.CreateCellStyle();
//字体
var font1 = wb.CreateFont();
//字体颜色
font1.Color = HSSFColor.White.Index;
//字体加粗样式
font1.Boldweight = (short)FontBoldWeight.Bold;
//style1.FillBackgroundColor = HSSFColor.WHITE.index;
//GetXLColour(wb, LevelOneColor);
// 设置图案色
style1.FillForegroundColor = HSSFColor.Green.Index;
//GetXLColour(wb, LevelOneColor);// 设置背景色
style1.FillPattern = FillPattern.SolidForeground;
//样式里的字体设置具体的字体样式
style1.SetFont(font1);
//文字水平对齐方式
style1.Alignment = HorizontalAlignment.Center;
//文字垂直对齐方式
style1.VerticalAlignment = VerticalAlignment.Center;
row.HeightInPoints = 25;
for (j = 0; j < dt.Columns.Count; j++)
{
columnValue = dt.Columns[j].ColumnName;
curLength = Encoding.Default.GetByteCount(columnValue.ToString());
maxLength = (maxLength < curLength ? curLength : maxLength);
var colounwidth = 256 * maxLength;
sheet.SetColumnWidth(j, colounwidth);
try
{
//创建第0行的第j列
cell = row.CreateCell(j);
//单元格式设置样式
cell.CellStyle = style1;
try
{
cell.SetCellValue(columnValue.ToString());
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
// 创建每一行
for (var i = startRow; i < ds.Tables[0].Rows.Count; i++)
{
var dr = ds.Tables[0].Rows[i];
//创建第i行
row = sheet.CreateRow(i + 1);
for (j = 0; j < dt.Columns.Count; j++)
{
columnValue = dr[j];
curLength = Encoding.Default.GetByteCount(columnValue.ToString());
maxLength = (maxLength < curLength ? curLength : maxLength);
var colounwidth = 256 * maxLength;
sheet.SetColumnWidth(j, colounwidth);
try
{
//创建第i行的第j列
cell = row.CreateCell(j);
// 插入第j列的数据
try
{
var dtype = datatypes[j];
switch (dtype)
{
case NpoiDataType.String:
{
cell.SetCellValue(columnValue.ToString());
}
break;
case NpoiDataType.Datetime:
{
cell.SetCellValue(columnValue.ToString());
}
break;
case NpoiDataType.Numeric:
{
cell.SetCellValue(Convert.ToDouble(columnValue));
}
break;
case NpoiDataType.Bool:
{
cell.SetCellValue(Convert.ToBoolean(columnValue));
}
break;
case NpoiDataType.Richtext:
{
cell.SetCellValue(columnValue.ToString());
}
break;
}
}
catch (Exception ex)
{
cell.SetCellValue(columnValue.ToString());
throw new Exception(ex.Message);
}
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
}
//生成文件在服务器上
using (var fs = new FileStream(saveFileName, FileMode.OpenOrCreate, FileAccess.Write))
{
wb.Write(fs);
}
return true;
}
catch (Exception er)
{
throw new Exception(er.Message);
}
}
7.读Excel-根据NpoiDataType创建的DataTable列的数据类型：
/// <summary>
/// 读Excel-根据NpoiDataType创建的DataTable列的数据类型
/// </summary>
/// <param name="datatype"></param>
/// <returns></returns>
private static Type GetDataTableType(NpoiDataType datatype)
{
var tp = typeof(string);
switch (datatype)
{
case NpoiDataType.Bool:
tp = typeof(bool);
break;
case NpoiDataType.Datetime:
tp = typeof(DateTime);
break;
case NpoiDataType.Numeric:
tp = typeof(double);
break;
case NpoiDataType.Error:
tp = typeof(string);
break;
case NpoiDataType.Blank:
tp = typeof(string);
break;
}
return tp;
}
/// <summary>
/// 读Excel-得到不同数据类型单元格的数据
/// </summary>
/// <param name="datatype">数据类型</param>
/// <param name="row">数据中的一行</param>
/// <param name="column">哪列</param>
/// <returns></returns>
private static object GetCellData(NpoiDataType datatype, IRow row, int column)
{
switch (datatype)
{
case NpoiDataType.String:
try
{
return row.GetCell(column).DateCellValue;
}
catch
{
try
{
return row.GetCell(column).StringCellValue;
}
catch
{
return row.GetCell(column).NumericCellValue;
}
}
case NpoiDataType.Bool:
try { return row.GetCell(column).BooleanCellValue; }
catch { return row.GetCell(column).StringCellValue; }
case NpoiDataType.Datetime:
try { return row.GetCell(column).DateCellValue; }
catch { return row.GetCell(column).StringCellValue; }
case NpoiDataType.Numeric:
try { return row.GetCell(column).NumericCellValue; }
catch { return row.GetCell(column).StringCellValue; }
case NpoiDataType.Richtext:
try { return row.GetCell(column).RichStringCellValue; }
catch { return row.GetCell(column).StringCellValue; }
case NpoiDataType.Error:
try { return row.GetCell(column).ErrorCellValue; }
catch { return row.GetCell(column).StringCellValue; }
case NpoiDataType.Blank:
try { return row.GetCell(column).StringCellValue; }
catch { return ""; }
default: return "";
}
}
/// <summary>
/// 获取单元格数据类型
/// </summary>
/// <param name="hs">单元格对象</param>
/// <returns></returns>
private static NpoiDataType GetCellDataType(ICell hs)
{
NpoiDataType dtype;
DateTime t1;
var cellvalue = "";
switch (hs.CellType)
{
case CellType.Blank:
dtype = NpoiDataType.String;
cellvalue = hs.StringCellValue;
break;
case CellType.Boolean:
dtype = NpoiDataType.Bool;
break;
case CellType.Numeric:
dtype = NpoiDataType.Numeric;
cellvalue = hs.NumericCellValue.ToString(CultureInfo.InvariantCulture);
break;
case CellType.String:
dtype = NpoiDataType.String;
cellvalue = hs.StringCellValue;
break;
case CellType.Error:
dtype = NpoiDataType.Error;
break;
default:
dtype = NpoiDataType.Datetime;
break;
}
if (cellvalue != "" && DateTime.TryParse(cellvalue, out t1)) dtype = NpoiDataType.Datetime;
return dtype;
}
四.总结：
本文是接着上五篇介绍.NET组件，目的只是在于总结一些组件的用法，将文章作为一个引子，各位读者可以根据文章的介绍更加深入的去了解相关组件。有些地方写的有误，还望多多包涵和指正，欢迎大家给我建议介绍一些你们在项目中经常使用的组件，可以跟大家做一个分享。
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