C#：將.csv格式文件轉換成.xlsx格式文件

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;

namespace SettlementResolve
{
    public partial class JDSettlement : Form
    {
        public JDSettlement()
        {
            InitializeComponent();
        }

        private void txtbox_ReadOnlyChanged(object sender, EventArgs e)
        {
            txtbox.ReadOnly = true;
        }

        private void JDSettlement_Load(object sender, EventArgs e)
        {

        }

        /// <summary>
        /// 將.csv文件轉換成.xlsx文件
        /// </summary>
        /// <param name="FilePath">.csv文件絕對路徑</param>
        /// <returns>返回轉換后的.xlsx文件路徑</returns>
        public static string CSVSaveasXLSX(string FilePath)
        {
            QuertExcel();
            string NewFilePath = "";

            Excel.Application excelApplication;
            Excel.Workbooks excelWorkBooks = null;
            Excel.Workbook excelWorkBook = null;
            Excel.Worksheet excelWorkSheet = null;

            try
            {
                excelApplication = new Excel.Application();
                excelWorkBooks = excelApplication.Workbooks;
                excelWorkBook=((Excel.Workbook) excelWorkBooks.Open(FilePath,Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value,
                    Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value,Missing.Value));
                excelWorkSheet = (Excel.Worksheet)excelWorkBook.Worksheets[1];
                excelApplication.Visible = false;
                excelApplication.DisplayAlerts = false;
                NewFilePath = FilePath.Replace(".csv", ".xlsx");
                excelWorkBook.SaveAs(NewFilePath, Excel.XlFileFormat.xlAddIn, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value,
                    Missing.Value, Missing.Value, Missing.Value, Missing.Value);
                excelWorkBook.Close();
                QuertExcel();
                GC.Collect(System.GC.GetGeneration(excelWorkSheet));
                GC.Collect(System.GC.GetGeneration(excelWorkBook));
                GC.Collect(System.GC.GetGeneration(excelApplication));
            }
            catch (Exception exc)
            {
                throw new Exception(exc.Message);
            }

            finally
            {
                GC.Collect();
            }
            return NewFilePath;
        }

        /// <summary>
        /// 執行過程中可能會打開多個EXCEL文件,所以Kill掉
        /// </summary>
        private static void QuertExcel()
        {
            Process[] excels = Process.GetProcessesByName("EXCEL");
            foreach (var item in excels)
            {
                item.Kill();
            }
        }
    }
}

原文轉載自：http://www.cnblogs.com/junjie94wan/archive/2013/05/23/3094483.html

原文有個地方被我修改過來,在CSVSaveasXLS方法中

excelApplication = new Excel.ApplicationClass();
這行會出現以下的問題：

導致整個程序無法運行，所以我稍作修改成我以上所寫的代碼，運行調試后，暫無發現明顯問題。