一、创建一个类，将下面的代码(已封装好)写入
二、使用时直接调用
效果图
下面展示一些 内联代码片。
可以直接复制过去用，已封装好
public class ExcelHelper
{
/// <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 Export(DataTable dtSource, string strHeaderText)
{
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.CreateSheet("Sheet1");
#region 右击文件 属性信息
{
DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "";
workbook.DocumentSummaryInformation = dsi;
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Author = ""; //填加xls文件作者信息
si.ApplicationName = "NPOI测试程序"; //填加xls文件创建程序信息
si.LastAuthor = ""; //填加xls文件最后保存者信息
si.Comments = "说明信息"; //填加xls文件作者信息
si.Title = "NPOI测试"; //填加xls文件标题信息
si.Subject = "NPOI测试Demo";//填加文件主题信息
si.CreateDateTime = DateTime.Now;
workbook.SummaryInformation = si;
}
#endregion
HSSFCellStyle dateStyle = workbook.CreateCellStyle();
HSSFDataFormat format = 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 = workbook.CreateSheet();
}
#region 表头及样式
{
HSSFRow headerRow = sheet.CreateRow(0);
headerRow.HeightInPoints = 25;
headerRow.CreateCell(0).SetCellValue(strHeaderText);
HSSFCellStyle headStyle = workbook.CreateCellStyle();
// headStyle.Alignment = CellHorizontalAlignment.CENTER;
HSSFFont font = 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 = sheet.CreateRow(1);
HSSFCellStyle headStyle = workbook.CreateCellStyle();
// headStyle.Alignment = CellHorizontalAlignment.CENTER;
HSSFFont font = 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 = sheet.CreateRow(rowIndex);
foreach (DataColumn column in dtSource.Columns)
{
HSSFCell 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("");
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;
}
}
/// <summary>
/// 用于Web导出
/// </summary>
/// <param name="dtSource">源DataTable</param>
/// <param name="strHeaderText">表头文本</param>
/// <param name="strFileName">文件名</param>
public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName)
{
HttpContext curContext = HttpContext.Current;
// 设置编码和附件格式
curContext.Response.ContentType = "application/vnd.ms-excel";
curContext.Response.ContentEncoding = Encoding.UTF8;
curContext.Response.Charset = "";
curContext.Response.AppendHeader("Content-Disposition",
"attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));
curContext.Response.BinaryWrite(Export(dtSource, strHeaderText).GetBuffer());
curContext.Response.End();
}
/// <summary>读取excel
/// 默认第一行为标头
/// </summary>
/// <param name="strFileName">excel文档路径</param>
/// <returns></returns>
public static DataTable Import(string strFileName)
{
DataTable dt = new DataTable();
HSSFWorkbook hssfworkbook;
using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
{
hssfworkbook = new HSSFWorkbook(file);
}
HSSFSheet sheet = hssfworkbook.GetSheetAt(0);
System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
HSSFRow headerRow = sheet.GetRow(0);
int cellCount = headerRow.LastCellNum;
for (int j = 0; j < cellCount; j++)
{
HSSFCell cell = headerRow.GetCell(j);
dt.Columns.Add(cell.ToString());
}
for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
{
HSSFRow row = sheet.GetRow(i);
DataRow dataRow = dt.NewRow();
for (int j = row.FirstCellNum; j < cellCount; j++)
{
if (row.GetCell(j) != null)
dataRow[j] = row.GetCell(j).ToString();
}
dt.Rows.Add(dataRow);
}
return dt;
}
}
调用 注意格式
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