C# Winform Excel和CSV互转

 需要安装 office excel  

 

 public static class ExcelFormatHelper
    {
        /// <summary>
        /// 将Csv文件转换为XLS文件
        /// </summary>
        /// <param name="FilePath">文件全路路径</param>
        /// <returns>返回转换后的Xls文件名</returns>
        public static string CSVSaveasXLS(string FilePath)
        {
            QuertExcel();
            string _NewFilePath = "";
       
            Excel.Application excelApplication;
            Excel.Workbooks excelWorkBooks = null;
            Excel.Workbook excelWorkBook = null; 
            Excel.Worksheet excelWorkSheet = null;

            try
            {
                excelApplication = new Excel.ApplicationClass();
                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", ".xls");              
                excelWorkBook.SaveAs(_NewFilePath, Excel.XlFileFormat.xlAddIn8, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
                QuertExcel();
              // ExcelFormatHelper.DeleteFile(FilePath);
              //可以不用杀掉进程QuertExcel();

excelApplication.Quit();

GC.WaitForPendingFinalizers();
GC.Collect();

            }
            catch (Exception exc)
            {
                throw new Exception(exc.Message);
            }
　　　　　　　

finally
{
GC.Collect();
}

return _NewFilePath;
        }

        /// <summary>
        /// 将xls文件转换为csv文件
        /// </summary>
        /// <param name="FilePath">文件全路路径</param>
        /// <returns>返回转换后的csv文件名</returns>
        public static string XLSSavesaCSV(string FilePath)
        {
            QuertExcel();
            string _NewFilePath = "";

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

            try
            {
                excelApplication = new Excel.ApplicationClass();
                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(".xls", ".csv");
               // excelWorkSheet._SaveAs(FilePath, Excel.XlFileFormat.xlCSVWindows, Missing.Value, Missing.Value, Missing.Value,Missing.Value,Missing.Value, Missing.Value, Missing.Value);
                excelWorkBook.SaveAs(_NewFilePath, Excel.XlFileFormat.xlCSV, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
                QuertExcel();
                //ExcelFormatHelper.DeleteFile(FilePath);
            }
            catch (Exception exc)
            {
                throw new Exception(exc.Message);
            }
            return _NewFilePath;
        }

        /// <summary>
        /// 删除一个指定的文件
        /// </summary>
        /// <param name="FilePath">文件路径</param>
        /// <returns></returns>
        public static bool DeleteFile(string FilePath)
        {
            try
            {
                bool IsFind = File.Exists(FilePath);
                if (IsFind)
                {
                    File.Delete(FilePath);
                }
                else
                {
                    throw new IOException("指定的文件不存在");
                }
                return true;
            }
            catch (Exception exc)
            {
                throw new Exception(exc.Message);
            }
           
        }

        /// <summary>
        /// 执行过程中可能会打开多个EXCEL文件 所以杀掉
        /// </summary>
        private static void QuertExcel()
        {
            Process[] excels = Process.GetProcessesByName("EXCEL");
            foreach (var item in excels)
            {
                item.Kill();
            }         
        }
    }


----------------------------
下面的方法比较好

//将xml Excel转换为标准的CSV格式 
            Object Nothing = Missing.Value;//由于COM组件很多值需要用Missing.Value代替   
            Microsoft.Office.Interop.Excel.Application ExclApp = new Microsoft.Office.Interop.Excel.Application();// 初始化
            Microsoft.Office.Interop.Excel.Workbook ExclDoc = ExclApp.Workbooks.Open(savePath, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing);//打开Excl工作薄   
            try
            {
                Object format = Microsoft.Office.Interop.Excel.XlFileFormat.xlCSV;
                ExclApp.DisplayAlerts = false;
                ExclDoc.SaveAs(savePath.Replace("xls","csv"), format, Nothing, Nothing, Nothing, Nothing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Nothing, Nothing, Nothing, Nothing, Nothing);
            }
            catch (Exception ex) { }

　　　　　　　　ExclDoc.Close(Nothing, Nothing, Nothing);
　　　　　　　　NAR(ExclDoc);
　　　　　　　　ExclApp.Quit();
　　　　　　　　NAR(ExclApp);

　　　　　　　　
           GC.WaitForPendingFinalizers();

             GC.Collect();

/// <summary>
/// 释放资源
/// </summary>
/// <param name="o"></param>
private void NAR(object o)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(o);
}
catch { }
finally
{
o = null;
}
}