/// <summary>
/// DataTable导出到Excel的MemoryStream
/// </summary>
/// <param name="dtSource">源DataTable</param>
/// <param name="strHeaderText">表头文本</param>
public static MemoryStream DataTableToExcel(DataTable dtSource, string strHeaderText)
{
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
#region 右击文件 属性信息
{
DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "NPOI";
workbook.DocumentSummaryInformation = dsi;
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Author = "文件作者信息"; //填加xls文件作者信息
si.ApplicationName = "创建程序信息"; //填加xls文件创建程序信息
si.LastAuthor = "最后保存者信息"; //填加xls文件最后保存者信息
si.Comments = "作者信息"; //填加xls文件作者信息
si.Title = "标题信息"; //填加xls文件标题信息
si.Subject = "主题信息";//填加文件主题信息
si.CreateDateTime = System.DateTime.Now;
workbook.SummaryInformation = si;
}
#endregion
HSSFCellStyle dateStyle = (HSSFCellStyle)workbook.CreateCellStyle();
HSSFDataFormat format = (HSSFDataFormat)workbook.CreateDataFormat();
dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
//取得列宽
/*
int[] arrColWidth = new int[dtSource.Columns.Count];
foreach (DataColumn item in dtSource.Columns)
{
arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
}
for (int i = 0; i < dtSource.Rows.Count; i++)
{
for (int j = 0; j < dtSource.Columns.Count; j++)
{
int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
if (intTemp > arrColWidth[j])
{
arrColWidth[j] = intTemp;
}
}
}
*/
int rowIndex = 0;
foreach (DataRow row in dtSource.Rows)
{
#region 新建表,填充表头,填充列头,样式
if (rowIndex == 65535 || rowIndex == 0)
{
if (rowIndex != 0)
{
sheet = (HSSFSheet)workbook.CreateSheet();
}
#region 表头及样式
{
HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
headerRow.HeightInPoints = 25;
headerRow.CreateCell(0).SetCellValue(strHeaderText);
HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
// headStyle.Alignment = CellHorizontalAlignment.CENTER;
HSSFFont font = (HSSFFont)workbook.CreateFont();
font.FontHeightInPoints = 20;
font.Boldweight = 700;
headStyle.SetFont(font);
headerRow.GetCell(0).CellStyle = headStyle;
// sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
//headerRow.Dispose();
}
#endregion
#region 列头及样式
{
HSSFRow headerRow = (HSSFRow)sheet.CreateRow(1);
HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
//headStyle.Alignment = CellHorizontalAlignment.CENTER;
HSSFFont font = (HSSFFont)workbook.CreateFont();
font.FontHeightInPoints = 10;
font.Boldweight = 700;
headStyle.SetFont(font);
foreach (DataColumn column in dtSource.Columns)
{
headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
//设置列宽
// sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
}
// headerRow.Dispose();
}
#endregion
rowIndex = 2;
}
#endregion
#region 填充内容
HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
foreach (DataColumn column in dtSource.Columns)
{
HSSFCell newCell = (HSSFCell)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
System.DateTime dateV;
System.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("");
break;
}
}
#endregion
rowIndex++;
}
using (MemoryStream ms = new MemoryStream())
{
workbook.Write(ms);
ms.Flush();
ms.Position = 0;
// sheet.Dispose();
//workbook.Dispose();//一般只用写这一个就OK了,他会遍历并释放所有资源,但当前版本有问题所以只释放sheet
return ms;
}
}