public class ExcelHelperExpend
{

public ExcelHelperExpend() { }

/// <summary>
/// 文件流初始化对象
/// </summary>
/// <param name="stream"></param>
public ExcelHelperExpend(Stream stream)
{
_IWorkbook = CreateWorkbook(stream);
}

/// <summary>
/// 传入文件名
/// </summary>
/// <param name="fileName"></param>
public ExcelHelperExpend(string fileName)
{
using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
{
_IWorkbook = CreateWorkbook(fileStream);
}
}

/// <summary>
/// 工作薄
/// </summary>
private IWorkbook _IWorkbook;

/// <summary>
/// 创建工作簿对象
/// </summary>
/// <param name="stream"></param>
/// <returns></returns>
private IWorkbook CreateWorkbook(Stream stream)
{
try
{
return new HSSFWorkbook(stream); //03
}
catch
{
return new HSSFWorkbook(stream); //03
}

}

public HSSFWorkbook ExportWorkbook<T>(List<T> list, string[] propertys, string[] columns) where T : class
{

var workbook = new HSSFWorkbook();

workbook.CreateSheet("Sheet1");

workbook.GetSheetAt(0).CreateRow(0);

for (int i = 0; i < columns.Length; i++)
{
workbook.GetSheetAt(0).GetRow(0).CreateCell(i);
workbook.GetSheetAt(0).GetRow(0).GetCell(i).SetCellValue(columns[i]);

}

for (var i = 0; i < list.Count; i++)
{
workbook.GetSheetAt(0).CreateRow(i + 1);

for (int j = 0; j < propertys.Length; j++)
{
workbook.GetSheetAt(0).GetRow(i + 1).CreateCell(j);

var cellvalue = http://www.mamicode.com/list[i].GetType().GetProperty(propertys[j]).GetValue(list[i], null);
workbook.GetSheetAt(0).GetRow(i + 1).GetCell(j).SetCellValue(cellvalue.ToString());

}
}

//打开xls文件，如没有则创建，如存在则在创建是不要打开该文件
/* using (var fs = File.OpenWrite(@"c:/joye.net.xls"))
{
workbook.Write(fs); //向打开的这个xls文件中写入mySheet表并保存。
// Console.WriteLine("生成成功");
}*/

return workbook;
}

/// <summary>
/// 把Sheet中的数据转换为DataTable
/// </summary>
/// <param name="sheet"></param>
/// <returns></returns>
private DataTable ExportToDataTable(ISheet sheet)
{
DataTable dt = new DataTable();

//默认，第一行是字段
IRow headRow = sheet.GetRow(0);

//设置datatable字段
for (int i = headRow.FirstCellNum, len = headRow.LastCellNum; i < len; i++)
{
dt.Columns.Add(headRow.Cells[i].StringCellValue);
}
//遍历数据行
for (int i = (sheet.FirstRowNum + 1), len = sheet.LastRowNum + 1; i < len; i++)
{
IRow tempRow = sheet.GetRow(i);
DataRow dataRow = dt.NewRow();

//遍历一行的每一个单元格
for (int r = 0, j = tempRow.FirstCellNum, len2 = tempRow.LastCellNum; j < len2; j++, r++)
{

ICell cell = tempRow.GetCell(j);

if (cell != null)
{
switch (cell.CellType)
{
case CellType.STRING:
dataRow[r] = cell.StringCellValue;
break;
case CellType.NUMERIC:
dataRow[r] = cell.NumericCellValue;
break;
case CellType.BOOLEAN:
dataRow[r] = cell.BooleanCellValue;
break;
default: dataRow[r] = "ERROR";
break;
}
}
}
dt.Rows.Add(dataRow);
}
return dt;
}

private IList<T> ExportList<T>(ISheet sheet, string[] fields) where T : class, new()
{
IList<T> list = new List<T>();

for (int i = 1; i < sheet.LastRowNum + 1; i++)
{
T t = new T();
IRow row = sheet.GetRow(i);

for (int j = 0; j < fields.Length; j++)
{
if (fields[j] == null)
{
continue;
}
ICell cell = row.GetCell(j);
object cellValue = http://www.mamicode.com/null;
switch (cell.CellType)
{
case CellType.STRING: //文本
cellValue = http://www.mamicode.com/cell.StringCellValue;
break;
case CellType.NUMERIC: //数值
cellValue = http://www.mamicode.com/cell.NumericCellValue;//Double转换为int
break;
case CellType.BOOLEAN: //bool
cellValue = http://www.mamicode.com/cell.BooleanCellValue;
break;
case CellType.BLANK: //空白
cellValuehttp://www.mamicode.com/= "";
break;
default: cellValuehttp://www.mamicode.com/= "ERROR";
break;
}

typeof(T).GetProperty(fields[j]).SetValue(t, cellValue.ToString(), null);
}
list.Add(t);
}
return list;
}

/// <summary>
/// Sheet中的数据转换为List集合
/// </summary>
/// <param name="sheet"></param>
/// <param name="fields"></param>
/// <returns></returns>
private IList<T> ExportToList<T>(ISheet sheet, string[] fields) where T : class,new()
{
IList<T> list = new List<T>();

//遍历每一行数据
for (int i = sheet.FirstRowNum + 1, len = sheet.LastRowNum + 1; i < len; i++)
{
T t = new T();

IRow row = sheet.GetRow(i);

for (int j = 0, len2 = fields.Length; j < len2; j++)
{
ICell cell = row.GetCell(j);
object cellValue = http://www.mamicode.com/null;

switch (cell.CellType)
{
case CellType.STRING: //文本
cellValue = http://www.mamicode.com/cell.StringCellValue;
break;
case CellType.NUMERIC: //数值
cellValue = http://www.mamicode.com/cell.NumericCellValue;//Double转换为int
break;
case CellType.BOOLEAN: //bool
cellValue = http://www.mamicode.com/cell.BooleanCellValue;
break;
case CellType.BLANK: //空白
cellValuehttp://www.mamicode.com/= "";
break;
default: cellValuehttp://www.mamicode.com/= "ERROR";
break;
}

typeof(T).GetProperty(fields[j]).SetValue(t, cellValue.ToString(), null);
}
list.Add(t);
}

return list;
}

/// <summary>
/// 获取第一个Sheet的第X行，第Y列的值。起始点为1
/// </summary>
/// <param name="X">行</param>
/// <param name="Y">列</param>
/// <returns></returns>
public string GetCellValue(int X, int Y)
{
ISheet sheet = _IWorkbook.GetSheetAt(0);

IRow row = sheet.GetRow(X - 1);

return row.GetCell(Y - 1).ToString();
}

/// <summary>
/// 获取一行的所有数据
/// </summary>
/// <param name="X">第x行</param>
/// <returns></returns>
public string[] GetCells(int X)
{
List<string> list = new List<string>();

ISheet sheet = _IWorkbook.GetSheetAt(0);

IRow row = sheet.GetRow(X - 1);

for (int i = 0, len = row.LastCellNum; i < len; i++)
{
list.Add(row.GetCell(i).StringCellValue);//这里没有考虑数据格式转换，会出现bug
}
return list.ToArray();
}

/// <summary>
/// 第一个Sheet数据，转换为DataTable
/// </summary>
/// <returns></returns>
public DataTable ExportExcelToDataTable()
{
return ExportToDataTable(_IWorkbook.GetSheetAt(0));
}

/// <summary>
/// 第sheetIndex表数据，转换为DataTable
/// </summary>
/// <param name="sheetIndex">第几个Sheet，从1开始</param>
/// <returns></returns>
public DataTable ExportExcelToDataTable(int sheetIndex)
{
return ExportToDataTable(_IWorkbook.GetSheetAt(sheetIndex - 1));
}

/// <summary>
/// Excel中默认第一张Sheet导出到集合
/// </summary>
/// <param name="fields">Excel各个列，依次要转换成为的对象字段名称</param>
/// <returns></returns>
public IList<T> ExcelToList<T>(string[] fields) where T : class,new()
{
return ExportToList<T>(_IWorkbook.GetSheetAt(0), fields);
}
public IList<T> ExcelList<T>(string[] fields) where T : class,new()
{
return ExportList<T>(_IWorkbook.GetSheetAt(0), fields);
}

/// <summary>
/// Excel中指定的Sheet导出到集合
/// </summary>
/// <param name="sheetIndex">第几张Sheet,从1开始</param>
/// <param name="fields">Excel各个列，依次要转换成为的对象字段名称</param>
/// <returns></returns>
public IList<T> ExcelToList<T>(int sheetIndex, string[] fields) where T : class,new()
{
return ExportToList<T>(_IWorkbook.GetSheetAt(sheetIndex - 1), fields);
}

}

excelhelper