标签：blog http io os 使用 ar for strong 数据
从DataTable读取内容来创建Workbook对象：
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public static MemoryStream RenderToExcel(DataTable table){ MemoryStream ms = new MemoryStream(); using (table) { using (IWorkbook workbook = new HSSFWorkbook()) { using (ISheet sheet = workbook.CreateSheet()) { IRow headerRow = sheet.CreateRow(0); // handling header. foreach (DataColumn column in table.Columns) headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//If Caption not set, returns the ColumnName value // handling value. int rowIndex = 1; foreach (DataRow row in table.Rows) { IRow dataRow = sheet.CreateRow(rowIndex); foreach (DataColumn column in table.Columns) { dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString()); } rowIndex++; } workbook.Write(ms); ms.Flush(); ms.Position = 0; } } } return ms;} |
如果看不惯DataTable，那么DataReader也行：
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public static MemoryStream RenderToExcel(IDataReader reader){ MemoryStream ms = new MemoryStream(); using (reader) { using (IWorkbook workbook = new HSSFWorkbook()) { using (ISheet sheet = workbook.CreateSheet()) { IRow headerRow = sheet.CreateRow(0); int cellCount = reader.FieldCount; // handling header. for (int i = 0; i < cellCount; i++) { headerRow.CreateCell(i).SetCellValue(reader.GetName(i)); } // handling value. int rowIndex = 1; while (reader.Read()) { IRow dataRow = sheet.CreateRow(rowIndex); for (int i = 0; i < cellCount; i++) { dataRow.CreateCell(i).SetCellValue(reader[i].ToString()); } rowIndex++; } workbook.Write(ms); ms.Flush(); ms.Position = 0; } } } return ms;} |
以上代码把创建的Workbook对象保存到流中，可以通过以下方法输出到浏览器，或是保存到硬盘中：
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static void SaveToFile(MemoryStream ms, string fileName){ using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write)) { byte[] data = ms.ToArray(); fs.Write(data, 0, data.Length); fs.Flush(); data = null; }}static void RenderToBrowser(MemoryStream ms, HttpContext context, string fileName){ if (context.Request.Browser.Browser == "IE") fileName = HttpUtility.UrlEncode(fileName); context.Response.AddHeader("Content-Disposition", "attachment;fileName=" + fileName); context.Response.BinaryWrite(ms.ToArray());} |
需要注意的是，sheet.LastRowNum = sheet.PhysicalNumberOfRows - 1，这里可能存在BUG：当没有数据或只有一行数据时sheet.LastRowNum为0，PhysicalNumberOfRows 表现正常。
这里读取流中的Excel来创建Workbook对象，并转换成DataTable：
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static DataTable RenderFromExcel(Stream excelFileStream){ using (excelFileStream) { using (IWorkbook workbook = new HSSFWorkbook(excelFileStream)) { using (ISheet sheet = workbook.GetSheetAt(0))//取第一个表 { DataTable table = new DataTable(); IRow headerRow = sheet.GetRow(0);//第一行为标题行 int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1 //handling header. 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 + 1); 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] = GetCellValue(row.GetCell(j)); } } table.Rows.Add(dataRow); } return table; } } }} |
或者是直接生成SQL语句来插入到数据库：
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public static int RenderToDb(Stream excelFileStream, string insertSql, DBAction dbAction){ int rowAffected = 0; using (excelFileStream) { using (IWorkbook workbook = new HSSFWorkbook(excelFileStream)) { using (ISheet sheet = workbook.GetSheetAt(0))//取第一个工作表 { StringBuilder builder = new StringBuilder(); IRow headerRow = sheet.GetRow(0);//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 + 1); 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}‘,", GetCellValue(row.GetCell(j)).Replace("‘", "‘‘")); } builder.Length = builder.Length - 1; builder.Append(");"); } if ((i % 50 == 0 || i == rowCount) && builder.Length > 0) { //每50条记录一次批量插入到数据库 rowAffected += dbAction(builder.ToString()); builder.Length = 0; } } } } } return rowAffected;} |
这里的Excel可能没有数据，所以可以加一个方法来检测：
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public static bool HasData(Stream excelFileStream){ using (excelFileStream) { using (IWorkbook workbook = new HSSFWorkbook(excelFileStream)) { if (workbook.NumberOfSheets > 0) { using (ISheet sheet = workbook.GetSheetAt(0)) { return sheet.PhysicalNumberOfRows > 0; } } } } return false;} |
转自http://www.cnblogs.com/lwme/archive/2011/11/18/npoi_excel_import_export.html
标签：blog http io os 使用 ar for strong 数据
原文地址：http://www.cnblogs.com/cmr000/p/4015261.html
