该文将介绍如何使用Spire.XLS 在.NET应用程序中通过设置线条起点和终点，然后以这两个点的位置添加线条到Excel工作表。线条起点和终点的位置可以为相对位置或绝对位置。详细代码：

using Spire.Xls;
using Spire.Xls.Core.Spreadsheet.Shapes;
using System.Drawing;

namespace AddLinestoExcel
{
    class Program
    {
        static void Main(string[] args)

        {
            //新建workbook并获取第一个工作表
            Workbook workbook = new Workbook();
            Worksheet worksheet = workbook.Worksheets[0];

            //通过相对位置添加线条
            XlsLineShape line = worksheet.TypedLines.AddLine() as XlsLineShape;
            //设置线条起点位置
            line.LeftColumn = 2;
            line.LeftColumnOffset = 2;
            line.TopRow = 5;
            line.TopRowOffset = 10;

            //设置线条终点位置
            line.RightColumn = 10;
            line.RightColumnOffset = 10;
            line.BottomRow =5;
            line.BottomRowOffset = 10; 

            //设置线条颜色
            line.Color = Color.Red;


            //通过绝对位置添加线条，单位为像素
            XlsLineShape line1 = worksheet.TypedLines.AddLine() as XlsLineShape;
            //设置线条起点和终点位置
            line1.StartPoint = new Point(20, 30);
            line1.EndPoint = new Point(200, 30);

            //设置线条颜色
            line1.Color = Color.Blue;
            
            workbook.SaveToFile("Addlines.xlsx", ExcelVersion.Version2013);
            workbook.Dispose();
        }
    }
 }

Imports Spire.Xls
Imports Spire.Xls.Core.Spreadsheet.Shapes
Imports System.Drawing

Namespace AddLinestoExcel
    
    Class Program
        
        Private Shared Sub Main(ByVal args() As String)
            '新建workbook并获取第一个工作表
            Dim workbook As Workbook = New Workbook
            Dim worksheet As Worksheet = workbook.Worksheets(0)
            '通过相对位置添加线条
            Dim line As XlsLineShape = CType(worksheet.TypedLines.AddLine,XlsLineShape)
            '设置线条起点位置
            line.LeftColumn = 2
            line.LeftColumnOffset = 2
            line.TopRow = 5
            line.TopRowOffset = 10
            '设置线条终点位置
            line.RightColumn = 10
            line.RightColumnOffset = 10
            line.BottomRow = 5
            line.BottomRowOffset = 10
            '设置线条颜色
            line.Color = Color.Red
            //通过绝对位置添加线条，单位为像素
            Dim line1 As XlsLineShape = CType(worksheet.TypedLines.AddLine,XlsLineShape)
            '设置线条起点和终点位置
            line1.StartPoint = New Point(20, 30)
            line1.EndPoint = New Point(200, 30)
            '设置线条颜色 
            line1.Color = Color.Blue
            workbook.SaveToFile("Addlines.xlsx", ExcelVersion.Version2013)
            workbook.Dispose
        End Sub 
    End Class
End Namespace

效果图：