数字格式使指能够控制Excel单元格中数字如何显示的格式字符串。例如，我们可以对数字12345应用数字格式“0.00”，使之显示为12345.00。数字格式字符串通常由以下某个或某几个说明符构成：

• # ：数字占位符
• 0 ：0占位符
• . ：小数点
• , ：分组符
• % ：百分号占位符
• [Red] ：颜色说明符

更多格式说明符，请参阅：https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-numeric-format-strings

//初始化Workbook对象
Workbook workbook = new Workbook();

//获取第一个工作表
Worksheet sheet = workbook.Worksheets[0];

//写入文本到B1，C1
sheet.Range["B1"].Text = "数字格式";
sheet.Range["C1"].Text = "数字±12345678应用格式后的效果";
sheet.Range["B1"].Style.Font.IsBold = true;
sheet.Range["C1"].Style.Font.IsBold = true;

//在B3中写入文本（即数字格式），在C3中写数字并应用数字格式
sheet.Range["B3"].Text = "0";
sheet.Range["C3"].NumberValue = 12345678;
sheet.Range["C3"].NumberFormat = "0";

//重复上面的步骤写入更多格式及对应效果
sheet.Range["B4"].Text = "0.00";
sheet.Range["C4"].NumberValue = 12345678;
sheet.Range["C4"].NumberFormat = "0.00";

sheet.Range["B5"].Text = "#,##0.00";
sheet.Range["C5"].NumberValue = 12345678;
sheet.Range["C5"].NumberFormat = "#,##0.00";

sheet.Range["B6"].Text = "￥#,##0.00";
sheet.Range["C6"].NumberValue = 12345678;
sheet.Range["C6"].NumberFormat = "￥#,##0.00";

sheet.Range["B7"].Text = "0;[Red]-0";
sheet.Range["C7"].NumberValue = -12345678;
sheet.Range["C7"].NumberFormat = "0;[Red]-0";

sheet.Range["B8"].Text = "0.00;[Red]-0.00";
sheet.Range["C8"].NumberValue = -12345678;
sheet.Range["C8"].NumberFormat = "0.00;[Red]-0.00";

sheet.Range["B9"].Text = "#,##0;[Red]-#,##0";
sheet.Range["C9"].NumberValue = -12345678;
sheet.Range["C9"].NumberFormat = "#,##0;[Red]-#,##0";

sheet.Range["B10"].Text = "#,##0.00;[Red]-#,##0.000";
sheet.Range["C10"].NumberValue = -12345678;
sheet.Range["C10"].NumberFormat = "#,##0.00;[Red]-#,##0.00";

sheet.Range["B11"].Text = "0.00E+00";
sheet.Range["C11"].NumberValue = 12345678;
sheet.Range["C11"].NumberFormat = "0.00E+00";

sheet.Range["B12"].Text = "0.00%";
sheet.Range["C12"].NumberValue = 12345678;
sheet.Range["C12"].NumberFormat = "0.00%";

//设置[B3:B12]、[C3:C12]背景颜色
sheet.Range["B3:B12"].Style.KnownColor = ExcelColors.Gray25Percent;
sheet.Range["C3:C12"].Style.KnownColor = ExcelColors.Gray50Percent;

//设置2、3列列宽
sheet.Columns[1].ColumnWidth = 25;
sheet.Columns[2].ColumnWidth = 30;

//保存文档
workbook.SaveToFile("output.xlsx", ExcelVersion.Version2013);

'初始化Workbook对象
Dim workbook As New Workbook()

'获取第一个工作表
Dim sheet As Worksheet = workbook.Worksheets(0)

'写入文本到B1，C1
sheet.Range("B1").Text = "数字格式"
sheet.Range("C1").Text = "数字±12345678应用格式后的效果"
sheet.Range("B1").Style.Font.IsBold = True
sheet.Range("C1").Style.Font.IsBold = True

'在B3中写入文本（即数字格式），在C3中写数字并应用数字格式
sheet.Range("B3").Text = "0"
sheet.Range("C3").NumberValue = 12345678
sheet.Range("C3").NumberFormat = "0"

'重复上面的步骤写入更多格式及对应效果
sheet.Range("B4").Text = "0.00"
sheet.Range("C4").NumberValue = 12345678
sheet.Range("C4").NumberFormat = "0.00"

sheet.Range("B5").Text = "#,##0.00"
sheet.Range("C5").NumberValue = 12345678
sheet.Range("C5").NumberFormat = "#,##0.00"

sheet.Range("B6").Text = "￥#,##0.00"
sheet.Range("C6").NumberValue = 12345678
sheet.Range("C6").NumberFormat = "￥#,##0.00"

sheet.Range("B7").Text = "0;[Red]-0"
sheet.Range("C7").NumberValue = -12345678
sheet.Range("C7").NumberFormat = "0;[Red]-0"

sheet.Range("B8").Text = "0.00;[Red]-0.00"
sheet.Range("C8").NumberValue = -12345678
sheet.Range("C8").NumberFormat = "0.00;[Red]-0.00"

sheet.Range("B9").Text = "#,##0;[Red]-#,##0"
sheet.Range("C9").NumberValue = -12345678
sheet.Range("C9").NumberFormat = "#,##0;[Red]-#,##0"

sheet.Range("B10").Text = "#,##0.00;[Red]-#,##0.000"
sheet.Range("C10").NumberValue = -12345678
sheet.Range("C10").NumberFormat = "#,##0.00;[Red]-#,##0.00"

sheet.Range("B11").Text = "0.00E+00"
sheet.Range("C11").NumberValue = 12345678
sheet.Range("C11").NumberFormat = "0.00E+00"

sheet.Range("B12").Text = "0.00%"
sheet.Range("C12").NumberValue = 12345678
sheet.Range("C12").NumberFormat = "0.00%"

'设置[B3:B12]、[C3:C12]背景颜色
sheet.Range("B3:B12").Style.KnownColor = ExcelColors.Gray25Percent
sheet.Range("C3:C12").Style.KnownColor = ExcelColors.Gray50Percent

'设置2、3列列宽
sheet.Columns(1).ColumnWidth = 25
sheet.Columns(2).ColumnWidth = 30

'保存文档
workbook.SaveToFile("output.xlsx", ExcelVersion.Version2013)