1.通过FileStream新建xls文件

FileStream FS = new FileStream(@"H:\test1.xls", FileMode.Create);   //新建xls文件

2.添加引用

using NPOI.HSSF.UserModel;using NPOI.SS.UserModel;using System.IO;

3.创建一个Sheet

HSSFWorkbook HB = new HSSFWorkbook(); ISheet Sheet1 = HB.CreateSheet("One");  //创建一个Sheet

 

4.设置单元的宽度高度并插入数据

Sheet1.SetColumnWidth(0, 15 * 256);Sheet1.SetColumnWidth(1, 15 * 256);Sheet1.SetColumnWidth(2, 15 * 256);Sheet1.SetColumnWidth(3, 15 * 256); for (int i = 0; i < 10; i++) {
         IRow row1 = Sheet1.CreateRow(i);       row1.Height = 20 * 20;      　　//设置行高       for (int j = 0; j < 10; j++)       {
             ICell cell1 = row1.CreateCell(j);           cell1.SetCellValue("第" + (i + 1) + "行，第" + (j + 1) + "列");       } } HB.Write(FS);　　//把流写入excel

 

起始四列设置了宽度，红线右边没有。自己对比看

 

 5.合并单元格

//CellRangeAddress（）该方法的参数次序是：开始行号，结束行号，开始列号，结束列号。Sheet1.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(11, 13, 0, 3));

合并效果：

 

 

整体

using System;      using System.Collections.Generic;      using System.Linq;      using System.Text;      using System.Threading.Tasks;      using NPOI.HSSF.UserModel;      using NPOI.SS.Formula.Eval;      using NPOI.SS.Formula.Functions;      using NPOI.SS.UserModel;      using NPOI.XSSF.UserModel;      using NPOI.POIFS.FileSystem;      using NPOI.HPSF;      using System.IO;      using NPOI.SS.Util;      using System.Drawing;      using NPOI.HSSF.Util;            namespace NPOI      {          class Program3          {              static void Main(string[] args)              {                  //说明：设置单元格对齐方式                        //1.创建EXCEL中的Workbook                           IWorkbook myworkbook = new XSSFWorkbook();                        //2.创建Workbook中的Sheet                          ISheet mysheet = myworkbook.CreateSheet("sheet1");                        mysheet.SetColumnWidth(0, 24 * 256);                  mysheet.SetColumnWidth(1, 24 * 256);                  mysheet.SetColumnWidth(2, 24 * 256);                  mysheet.SetColumnWidth(3, 24 * 256);                        //3.创建Row中的Cell并赋值                  IRow row0 = mysheet.CreateRow(0);                  row0.Height = 50 * 20;                  row0.CreateCell(0).SetCellValue("对齐方式");                  row0.CreateCell(1).SetCellValue("对齐方式");                  row0.CreateCell(2).SetCellValue("对齐方式");                  row0.CreateCell(3).SetCellValue("对齐方式");                        IRow row1 = mysheet.CreateRow(1);                  row1.Height = 50 * 20;                  row1.CreateCell(0).SetCellValue("对齐方式");                  row1.CreateCell(1).SetCellValue("Shanghai is the largest city by population in ");                  row1.CreateCell(2).SetCellValue("对齐方式");                  row1.CreateCell(3).SetCellValue("对齐方式");                        //4.创建CellStyle                  ICellStyle style0 = myworkbook.CreateCellStyle();                  style0.Alignment = HorizontalAlignment.General;//【General】数字、时间默认：右对齐；BOOL：默认居中；字符串：默认左对齐                        ICellStyle style1 = myworkbook.CreateCellStyle();                  style1.Alignment = HorizontalAlignment.Left;//【Left】左对齐                        ICellStyle style2 = myworkbook.CreateCellStyle();                  style2.Alignment = HorizontalAlignment.Center;//【Center】居中                        ICellStyle style3 = myworkbook.CreateCellStyle();                  style3.Alignment = HorizontalAlignment.Right;//【Right】右对齐                        ICellStyle style4 = myworkbook.CreateCellStyle();                  style4.Alignment = HorizontalAlignment.Fill;//【Fill】填充                        ICellStyle style5 = myworkbook.CreateCellStyle();                  style5.Alignment = HorizontalAlignment.Justify;//【Justify】两端对齐[会自动换行]（主要针对英文）                        ICellStyle style6 = myworkbook.CreateCellStyle();                  style6.Alignment = HorizontalAlignment.CenterSelection;//【CenterSelection】跨列居中                        ICellStyle style7 = myworkbook.CreateCellStyle();                  style7.Alignment = HorizontalAlignment.Distributed;//【Distributed】分散对齐[会自动换行]                        //【Tips】                  // 1.通过ICellStyle的VerticalAlignment属性可以设置垂直对齐模式与水平对齐无异 不再演示                  // 2.通过ISheet的SetDefaultColumnStyle(int column, ICellStyle style)方法可以设置整列的默认单元格样式;                                    //5.将CellStyle应用于具体单元格                  row0.GetCell(0).CellStyle = style0;                  row0.GetCell(1).CellStyle = style1;                  row0.GetCell(2).CellStyle = style2;                  row0.GetCell(3).CellStyle = style3;                        row1.GetCell(0).CellStyle = style4;                  row1.GetCell(1).CellStyle = style5;                  row1.GetCell(2).CellStyle = style6;                  row1.GetCell(3).CellStyle = style7;                        //6.保存                         FileStream file = new FileStream(@"E:\myworkbook3.xlsx", FileMode.Create);                  myworkbook.Write(file);                  file.Close();              }          }      }