C#操作Excel方法有很多，以前用的需要电脑安装office才能用，但因为版权问题公司不允许安装office。所以改用NPOI进行Excel操作，基本上一些简单的Excel操作都没有问题，读写合并单元格等都能实现。
命名空间：
using NPOI; using NPOI.XSSF.UserModel; using NPOI.SS.UserModel; using NPOI.HSSF.UserModel; using NPOI.HSSF.Util;
简单的保存数据：
public void ExcelTest(string path)
{
IWorkbook workbook = new HSSFWorkbook();//创建Workbook
workbook.CreateSheet("sheet1");//创建sheet
using (FileStream fs = File.Create(path))//path=mmm.xls;
{
ISheet sheet = workbook.GetSheetAt(0);//获取sheet
sheet.CreateRow(1).CreateCell(0).SetCellValue("nami");//创建第一行/创建第一单元格/设置第一单元格的内容[可以分开创建，但必须先创建行才能创建单元格不然报错]
sheet.GetRow(1).CreateCell(1).SetCellValue("robin");//获取第一行/创建第二单元格/设置第二单元格的内容
sheet.CreateRow(2).CreateCell(0).SetCellValue("saber");//创建第二行/创建第一单元格/设置第一单元格的内容
sheet.GetRow(2).CreateCell(1).SetCellValue("luffy");//获取第二行/创建第二单元格/设置第二单元格的内容
sheet.GetRow(1).CreateCell(2).SetCellValue(5);
sheet.GetRow(2).CreateCell(2).SetCellValue(2);
//添加批注
IDrawing draw = sheet.CreateDrawingPatriarch();
IComment comment = draw.CreateCellComment(new HSSFClientAnchor(0, 0, 0, 0, 1, 2, 4, 4));//里面参数应该是指示批注的位置大小吧
comment.String = new HSSFRichTextString("one-piece");//添加批注内容
comment.Author = "梦琪小生";//添加批注作者
sheet.GetRow(1).GetCell(1).CellComment = comment;//将之前设置的批注给定某个单元格
//单元格格式设置
ICellStyle cellStyle = workbook.CreateCellStyle();
IDataFormat format = workbook.CreateDataFormat();
cellStyle.DataFormat = format.GetFormat("0.00");
sheet.GetRow(2).GetCell(2).CellStyle = cellStyle;
//合并单元格
sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, 2));
sheet.CreateRow(0).CreateCell(0).SetCellValue("梦琪小生");
ICellStyle titleStyle = workbook.CreateCellStyle();
IFont titleFont = workbook.CreateFont();
titleFont.FontHeightInPoints = 15;//设置字体大小
titleFont.Color = HSSFColor.BLUE.index;//设置字体颜色
titleStyle.SetFont(titleFont);
titleStyle.Alignment = HorizontalAlignment.CENTER;//居中
sheet.GetRow(0).GetCell(0).CellStyle = titleStyle;
ICellStyle style = workbook.CreateCellStyle();
style.BorderBottom = BorderStyle.THIN;
style.BorderLeft = BorderStyle.THIN;
style.BorderRight = BorderStyle.THIN;
style.BorderTop = BorderStyle.THIN;
sheet.GetRow(1).GetCell(1).CellStyle = style;
//插入图片
HSSFClientAnchor anchor2 = new HSSFClientAnchor(0, 0, 0, 0, 0, 5, 6, 10);
byte[] bytes = System.IO.File.ReadAllBytes(@"C:UsersAdministratorDesktopimagemqxs.png");
int picID = workbook.AddPicture(bytes, PictureType.PNG);
IPicture pic = patriarch.CreatePicture(anchor2, picID);
pic.Resize();
workbook.Write(fs);//保存文件
}
}
读取Excel返回DataTable：
/// <summary>
/// 读取Excel[.xls](返回DataTable)
/// </summary>
/// <param name="path">Excel路径</param>
/// <returns></returns>
public static DataTable ReadExcel(string path)
{
try
{
DataTable dt = new DataTable();
using (FileStream fs = new FileStream(path, FileMode.Open))
{
IWorkbook workbook = new HSSFWorkbook(fs);
ISheet sheet = workbook.GetSheetAt(0);
int rfirst = sheet.FirstRowNum;
int rlast = sheet.LastRowNum;
IRow row = sheet.GetRow(rfirst);
int cfirst = row.FirstCellNum;
int clast = row.LastCellNum;
for (int i = cfirst; i < clast; i++)
{
if (row.GetCell(i) != null)
dt.Columns.Add(row.GetCell(i).StringCellValue, System.Type.GetType("System.String"));
}
row = null;
for (int i = rfirst + 1; i <= rlast; i++)
{
DataRow r = dt.NewRow();
IRow ir = sheet.GetRow(i);
for (int j = cfirst; j < clast; j++)
{
if (ir.GetCell(j) != null)
{
r[j] = ir.GetCell(j).ToString();
}
}
dt.Rows.Add(r);
ir = null;
r = null;
}
sheet = null;
workbook = null;
}
return dt;
}
catch
{
System.Windows.Forms.MessageBox.Show("Excel格式错误或者Excel正由另一进程在访问");
return null;
}
}
Ok,NPOI也用了一段时间了....
讲一点经验之谈...关于NPOI的单元格样式CellStyles个数是有限制的4000个，所以大家设置单元格样式的时候尽量不要再for循环里面定义，可以在for循环外围定义好使用...减少CellStyles个数,Ok，主要要讲的是下面的那一条....
((HSSFSheet)sheet).SetEnclosedBorderOfRegion(new NPOI.SS.Util.CellRangeAddress(0, 50, 0, 100), BorderStyle.MEDIUM, HSSFColor.BLACK.index);
这句的功能是给合并后的单元格加外边框。
比如这条语句的意思是将单元格0行0列到50行100列绘制一个整体的外边框。用到是很好用...但是很占资源，不知道为什么就这么一句话会占好几个CellStyles...而且速度较慢....
所以这个功能在数据量小的可以用，问题不大，速度基本影响也不大，但数据量一大...这个相对就会拖累速度了又太占资源.
小生我就在这边吃过亏，就是这条语句导致CellStyles个数不够用[当然不是一句就会有问题咯....因为很多地方合并单元格然后加外边框...最终就悲剧了....]....小生觉得这是NPOI的缺陷...
NPOI操作Excel使用说明：
官网教程相当详细，需进一步学习的请移步至官网学习 http://tonyqus.sinaapp.com/npoi2tutorial
2017/05/05补充：
C# Color转NPOI颜色：
/// <summary>
/// 获取颜色值
/// </summary>
/// <param name="color">颜色RGB</param>
/// <param name="workbook">Excel画布</param>
/// <returns></returns>
public static short GetColorIndex(this HSSFWorkbook workbook,Color color)
{
HSSFPalette palette = workbook.GetCustomPalette();
var v = palette.FindSimilarColor(color.R, color.G, color.B);
if (v == null)
{
throw new Exception("Color is not in Palette");
}
else return v.GetIndex();
}
2018/4/8补充：
获取合并单元格
/// <summary>
/// 获取当前单元格所在的合并单元格的位置
/// </summary>
/// <param name="sheet">sheet表单</param>
/// <param name="rowIndex">行索引 0开始</param>
/// <param name="colIndex">列索引 0开始</param>
/// <param name="start">合并单元格左上角坐标</param>
/// <param name="end">合并单元格右下角坐标</param>
/// <returns>返回false表示非合并单元格</returns>
private static bool IsMergeCell(ISheet sheet, int rowIndex, int colIndex, out Point start, out Point end)
{
bool result = false;
start = new Point(0, 0);
end = new Point(0, 0);
if ((rowIndex < 0) || (colIndex < 0)) return result;
int regionsCount = sheet.NumMergedRegions;
for (int i = 0; i < regionsCount; i++)
{
CellRangeAddress range = sheet.GetMergedRegion(i);
//sheet.IsMergedRegion(range);
if (rowIndex >= range.FirstRow && rowIndex <= range.LastRow && colIndex >= range.FirstColumn && colIndex <= range.LastColumn)
{
start = new Point(range.FirstRow, range.FirstColumn);
end = new Point(range.LastRow, range.LastColumn);
result = true;
break;
}
}
return result;
}
2020-09-29补充：（为啥这么多年了，还补充...因为换公司又用到了，就补充一下）
将DataTable导出Excel：
/// <summary>
/// 创建Excel
/// </summary>
/// <param name="savefile">保存路径</param>
/// <param name="title">表格标题</param>
/// <param name="dt">表格数据</param>
/// <returns></returns>
public static bool CreateExcel(string savefile, string title, DataTable dt)
{
try
{
if (dt.Columns.Count > 255)
{
throw new Exception("表格数据列超出最大值255");
}
IWorkbook workbook = new HSSFWorkbook();
ISheet sheet = workbook.CreateSheet("sheet1");
using (FileStream fs = File.Create(savefile))
{
int dtRowCount = dt.Rows.Count;
int dtcolumnCount = dt.Columns.Count;
#region[表格样式]
ICellStyle TitleStyle = MCellStyle.GetCellStyle(workbook, -1, "", 15, true, HSSFColor.Black.Index, HorizontalAlignment.Center, VerticalAlignment.Center, HSSFColor.Grey25Percent.Index);
ICellStyle columnStyle = MCellStyle.GetCellStyle(workbook, -1, "", 11, true, HSSFColor.Black.Index, HorizontalAlignment.Center, VerticalAlignment.Center, HSSFColor.Grey25Percent.Index);
ICellStyle limeStyle = MCellStyle.GetCellStyle(workbook, -1, "", 11, false, HSSFColor.Black.Index, HorizontalAlignment.Center, VerticalAlignment.Center, HSSFColor.White.Index);
ICellStyle roseStyle = MCellStyle.GetCellStyle(workbook, -1, "", 11, false, HSSFColor.Black.Index, HorizontalAlignment.Center, VerticalAlignment.Center, HSSFColor.White.Index);
#endregion
#region[设置标题]
sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 1, 0, dtcolumnCount - 1));
sheet.CreateRow(0); sheet.CreateRow(1);
sheet.GetRow(0).CreateCell(0).SetCellValue(title);
sheet.GetRow(0).GetCell(0).CellStyle = TitleStyle;
#endregion
#region[设置表头]
IRow row = sheet.CreateRow(2);
for (int j = 0; j < dtcolumnCount; j++)
{
row.CreateCell(j).SetCellValue(dt.Columns[j].ToString());
row.GetCell(j).CellStyle = columnStyle;
sheet.SetColumnWidth(j, 20 * 256);
}
row = null;
#endregion
#region[设置数据]
for (int i = 0; i < dtRowCount; i++)
{
IRow rows = sheet.CreateRow(i + 3);
for (int j = 0; j < dtcolumnCount; j++)
{
rows.CreateCell(j).SetCellValue(dt.Rows[i][j].ToString());
if (i % 2 == 0)
rows.GetCell(j).CellStyle = limeStyle;
else
rows.GetCell(j).CellStyle = roseStyle;
}
rows = null;
}
#endregion
#region[设置主边框]
sheet.GetRow(0).CreateCell(dtcolumnCount - 1).CellStyle = TitleStyle;
sheet.GetRow(1).CreateCell(dtcolumnCount - 1).CellStyle = TitleStyle;
//((HSSFSheet)sheet).SetEnclosedBorderOfRegion(new NPOI.SS.Util.CellRangeAddress(0, dtRowCount, 0, dtcolumnCount - 1), BorderStyle.MEDIUM, HSSFColor.Black.Index);
#endregion
#region[表格样式反设置]
TitleStyle = null;
columnStyle = null;
limeStyle = null;
roseStyle = null;
#endregion
workbook.Write(fs);
}
sheet = null;
workbook = null;
return true;
}
catch
{
return false;
}
}
创建样式：（2020-10-20增加样式的填充颜色）
public static class MCellStyle
{
/// <summary>
/// 获取NPOI的单元格样式
/// </summary>
/// <param name="workbook">表格</param>
/// <param name="cellstyleindex">单元格编号 默认-1即忽略编号</param>
/// <param name="fontname">字体名字</param>
/// <param name="fontsize">字体大小</param>
/// <param name="IsBold">是否加粗</param>
/// <param name="fillforecolor">填充颜色</param>
/// <param name="halignment">水平对齐方式</param>
/// <param name="valignment">垂直对齐方式</param>
/// <param name="fillbackcolor">背景颜色</param>
/// <param name="format">数字的格式"0.00"</param>
/// <returns>返回表格单元格样式CellStyle</returns>
public static ICellStyle GetCellStyle(IWorkbook workbook, short cellstyleindex = -1, string fontname = "", short fontsize = 11, bool IsBold = false, short fillforecolor = HSSFColor.COLOR_NORMAL, HorizontalAlignment halignment = HorizontalAlignment.Left, VerticalAlignment valignment = VerticalAlignment.Center, short fillbackcolor = HSSFColor.COLOR_NORMAL, string format = "")
{
if (cellstyleindex != -1)
{
try { return workbook.GetCellStyleAt(cellstyleindex); }
catch {; }
}
if (cellStyle != null) { cellStyle = null; }
cellStyle = workbook.CreateCellStyle();
IFont font = workbook.CreateFont();
if (fillforecolor != HSSFColor.COLOR_NORMAL)
font.Color = fillforecolor;
else
font.Color = HSSFColor.Black.Index;
if (fontsize > 0)
font.FontHeightInPoints = fontsize;
if (fontname != "")
font.FontName = fontname;
if (IsBold)
font.Boldweight = (short)NPOI.SS.UserModel.FontBoldWeight.Bold;
cellStyle.SetFont(font);
if (fillbackcolor != HSSFColor.COLOR_NORMAL)
{
cellStyle.FillForegroundColor = fillbackcolor;
cellStyle.FillPattern = FillPattern.SolidForeground;
}
if (format != "")
{
IDataFormat dataformat = workbook.CreateDataFormat();
cellStyle.DataFormat = dataformat.GetFormat(format);
}
cellStyle.Alignment = halignment;
cellStyle.VerticalAlignment = valignment;
cellStyle.BorderLeft = BorderStyle.Thin;
cellStyle.BorderRight = BorderStyle.Thin;
cellStyle.BorderTop = BorderStyle.Thin;
cellStyle.BorderBottom = BorderStyle.Thin;
cellStyle.WrapText = true;
return cellStyle;
}
/// <summary>
/// 获取NPOI的单元格样式（填充颜色精准）
/// </summary>
/// <param name="workbook">表格</param>
/// <param name="fillforecolor">填充颜色</param>
/// <param name="fillbackcolor">背景颜色</param>
/// <param name="cellstyleindex">单元格编号 默认-1即忽略编号</param>
/// <param name="fontname">字体名字</param>
/// <param name="fontsize">字体大小</param>
/// <param name="IsBold">是否加粗</param>
/// <param name="halignment">水平对齐方式</param>
/// <param name="valignment">垂直对齐方式</param>
/// <param name="format">数字的格式"0.00"</param>
/// <returns>返回表格单元格样式CellStyle</returns>
public static ICellStyle GetCellStyle(XSSFWorkbook workbook, Color fillforecolor, Color fillbackcolor, short cellstyleindex = -1, string fontname = "", short fontsize = 11, bool IsBold = false, HorizontalAlignment halignment = HorizontalAlignment.Left, VerticalAlignment valignment = VerticalAlignment.Center, string format = "")
{
if (cellstyleindex != -1)
{
try { return workbook.GetCellStyleAt(cellstyleindex); }
catch {; }
}
if (xssfcellStyle != null) { xssfcellStyle = null; }
xssfcellStyle = workbook.CreateCellStyle() as XSSFCellStyle;
XSSFFont font = workbook.CreateFont() as XSSFFont;
font.SetColor(new XSSFColor(new byte[] { fillforecolor.R, fillforecolor.G, fillforecolor.B }));
if (fontsize > 0)
font.FontHeightInPoints = fontsize;
if (fontname != "")
font.FontName = fontname;
if (IsBold)
font.Boldweight = (short)NPOI.SS.UserModel.FontBoldWeight.Bold;
xssfcellStyle.SetFont(font);
xssfcellStyle.FillPattern = FillPattern.SolidForeground;
if (xssfcellStyle.FillForegroundColorColor == null)
xssfcellStyle.FillForegroundColorColor = new XSSFColor(new byte[] { fillbackcolor.R, fillbackcolor.G, fillbackcolor.B });
else
((XSSFColor)xssfcellStyle.FillForegroundColorColor).SetRgb(new byte[] { fillbackcolor.R, fillbackcolor.G, fillbackcolor.B });
if (format != "")
{
IDataFormat dataformat = workbook.CreateDataFormat();
xssfcellStyle.DataFormat = dataformat.GetFormat(format);
}
xssfcellStyle.Alignment = halignment;
xssfcellStyle.VerticalAlignment = valignment;
xssfcellStyle.BorderLeft = BorderStyle.Thin;
xssfcellStyle.BorderRight = BorderStyle.Thin;
xssfcellStyle.BorderTop = BorderStyle.Thin;
xssfcellStyle.BorderBottom = BorderStyle.Thin;
xssfcellStyle.WrapText = true;
return xssfcellStyle;
}
/// <summary>
/// 获取颜色值(不精准)
/// </summary>
/// <param name="color">颜色RGB</param>
/// <param name="workbook">Excel画布</param>
/// <returns></returns>
public static short GetColorIndex(this HSSFWorkbook workbook, Color color)
{
HSSFPalette palette = workbook.GetCustomPalette();
var v = palette.FindSimilarColor(color.R, color.G, color.B);
if (v == null)
{
throw new Exception("Color is not in Palette");
}
else return v.Indexed;
}
private static ICellStyle cellStyle;
private static XSSFCellStyle xssfcellStyle;