C#匯出Excel（使用NPOI）
阿新 • • 發佈：2019-01-27
之前在C#網站或Webservice程式中一直使用COM元件的方式匯出Excel檔案，但是經常會出現除錯成功，但是部署到伺服器之後就失敗的現象。如果伺服器不是自己的，而要你到甲方那裡去部署，出現這種現象就尷尬了
。後來發現NPOI外掛非常好用，這裡總結一下。
下面是對NPOI常用方法做的一個封裝類，可以直接使用。
下面是呼叫方法，很簡單了using NPOI.HSSF.Util; using NPOI.SS.UserModel; using NPOI.SS.Util; using System; using System.Collections.Generic; using System.IO; using System.Text; namespace ExcelHelper { public class ExcelHelp { public static NPOI.HSSF.UserModel.HSSFWorkbook obook; public static NPOI.SS.UserModel.ISheet osheet; /// <summary> /// 建構函式，初始化表單物件 /// </summary> /// <param name="path"></param> /// <param name="sheetname"></param> public ExcelHelp() { obook = new NPOI.HSSF.UserModel.HSSFWorkbook(); osheet = obook.CreateSheet("sheet1"); } /// <summary> /// 合併單元格 /// </summary> /// <param name="r1">左上角單元格行標(從0開始，下同)</param> /// <param name="c1">左上角單元格列標</param> /// <param name="r2">右下角單元格行標</param> /// <param name="c2">右下角單元格列標</param> public void Merge( int r1,int c1,int r2,int c2) { osheet.AddMergedRegion(new CellRangeAddress(r1, c1, r2, c2)); } /// <summary> /// 設定單元格內容 /// </summary> /// <param name="row">單元格行標(從0開始，下同)</param> /// <param name="col">單元格列標</param> /// <param name="o">寫入內容</param> public void SetValue( int r, int c, object o) { if (o != null) { if(r<=osheet.LastRowNum) { IRow row = osheet.GetRow(r); if (row == null) { row = osheet.CreateRow(r); row.HeightInPoints = 14; } if(c<=row.LastCellNum) { ICell cell = row.GetCell(c); cell.SetCellValue(o.ToString()); } else { for(int j=row.LastCellNum;j<c;j++) { row.CreateCell(j + 1); ICell cell22 = row.GetCell(j + 1); ICellStyle style = obook.CreateCellStyle(); cell22.CellStyle = style; } ICell cell = row.GetCell(c); cell.SetCellValue(o.ToString()); } } else { for (int i = osheet.LastRowNum; i < r; i++) { IRow row22 = osheet.CreateRow(i + 1); row22.HeightInPoints = 14; } IRow row = osheet.GetRow(r); for (int j = row.LastCellNum; j < c; j++) { row.CreateCell(j + 1); ; ICell cell22 = row.GetCell(j + 1); ICellStyle style = obook.CreateCellStyle(); cell22.CellStyle = style; } ICell cell = row.GetCell(c); cell.SetCellValue(o.ToString()); } } } /// <summary> /// 設定行高 /// </summary> /// <param name="r">行數</param> /// <param name="height">高度</param> public void SetRowHeight(int r,int height) { if (r <= osheet.LastRowNum) { IRow row = osheet.GetRow(r); if (row != null) { row.HeightInPoints = height; } } } /// <summary> /// 設定字型寬度 /// </summary> /// <param name="c">列標</param> /// <param name="width">寬度值（例如設定為1，表示一個英文字元的寬度）</param> public void SetCollumWdith(int c, int width) { osheet.SetColumnWidth(c, 256 * width); } /// <summary> /// 設定單元格對齊方式 /// </summary> /// <param name="r">行標</param> /// <param name="c">列標</param> /// <param name="align">對齊方式（'L',左對齊；'C'居中；'R'右對齊）</param> public void SetCellAlignment(int r, int c, char align) { if(r<=osheet.LastRowNum) { IRow row = osheet.GetRow(r); if(row!=null) { if(c<=row.LastCellNum) { ICell cell = row.GetCell(c); ICellStyle style = cell.CellStyle; //設定單元格的樣式：水平對齊居中 if (align == 'C') style.Alignment = HorizontalAlignment.Center; else if (align == 'L') style.Alignment = HorizontalAlignment.Left; else if (align == 'R') style.Alignment = HorizontalAlignment.Right; cell.CellStyle = style; } } } } /// <summary> /// 設定字型樣式 /// </summary> /// <param name="r">行標</param> /// <param name="c">列標</param> /// <param name="size">字型大小，0為預設</param> /// <param name="f">字型樣式（‘B’加粗，‘I’斜體）</param> /// <param name="color">字型顏色('R'紅,'B'藍,'G'綠,'Y'黃,'P'粉,'O'橙,'W'白)</param> public void SetCellFont(int r, int c,int size, char f,char color) { if (r <= osheet.LastRowNum) { IRow row = osheet.GetRow(r); if (row != null) { if (c <= row.LastCellNum) { ICell cell = row.GetCell(c); ICellStyle style = cell.CellStyle; //新建一個字型樣式物件 IFont font = obook.CreateFont(); //設定字型大小 if(size>0) font.FontHeightInPoints = Convert.ToInt16(size); switch (f) { case 'B': { //設定字型加粗樣式 font.IsBold = true; } break; case 'I': { //設定字型加粗樣式 font.IsItalic = true; } break; } switch (color) { case 'R': { font.Color = HSSFColor.Red.Index; } break; case 'B': { font.Color = HSSFColor.Blue.Index; } break; case 'G': { font.Color = HSSFColor.Green.Index; } break; case 'Y': { font.Color = HSSFColor.Yellow.Index; } break; case 'P': { font.Color = HSSFColor.Pink.Index; } break; case 'O': { font.Color = HSSFColor.Orange.Index; } break; case 'W': { font.Color = HSSFColor.White.Index; } break; } //使用SetFont方法將字型樣式新增到單元格樣式中 style.SetFont(font); //將新的樣式賦給單元格 cell.CellStyle = style; } } } } /// <summary> /// 寫入到Excel文件 /// </summary> /// <param name="sheet"></param> /// <param name="path"></param> /// <returns></returns> public bool ExportToExcel(string path) { try { // 寫入到客戶端 using (FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite)) { obook.Write(fs); } return true; } catch { return false; } } public void Dispose() { obook.Close(); GC.Collect(); } } }
注意，這裡是winform的呼叫方法，如果是網頁（asp.net）匯出，函式ExportToExcel應該改寫為下面的形式：ExcelHelper.ExcelHelp myexcel = new ExcelHelper.ExcelHelp(); try { myexcel.Merge(0, 0, 0, 3); myexcel.SetValue(0, 0, "你好"); myexcel.SetRowHeight(0, 25); myexcel.SetCellAlignment(0, 0, 'C'); myexcel.SetCellFont(0, 0, 20,'B','R'); myexcel.SetValue(3, 0, "你好"); myexcel.SetValue(10, 5, "你好"); myexcel.SetCollumWdith(4, 20); myexcel.ExportToExcel("D:\\aaaabc.xls"); } catch { } finally { myexcel.Dispose(); }
System.IO.MemoryStream ms = new System.IO.MemoryStream(); obook.Write(ms); Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", DateTime.Now.ToString("yyyyMMddHHmmssfff"))); Response.BinaryWrite(ms.ToArray()); book = null; ms.Close(); ms.Dispose();