String batPath = "D:\\CIS\\rmyy.exe";
/// <summary>
/// 删除指定文件
/// </summary>
/// <param name="batPath">需要删除的文件路径</param>
public static void DeleteFile(string batPath)
{
    try
    {
            File.Delete(batPath);
    }
    catch
    {
        throw;
    }

public static void DelectDir(string srcPath)
{
    try
    {
        DirectoryInfo dir = new DirectoryInfo(srcPath);
        //返回目录中所有文件和子目录
        FileSystemInfo[] fileinfo = dir.GetFileSystemInfos();  
        foreach (FileSystemInfo i in fileinfo)
        {
            //判断是否文件夹
            if (i is DirectoryInfo)           
            {
                 DirectoryInfo subdir = new DirectoryInfo(i.FullName);
                 //删除子目录和文件
                 subdir.Delete(true);        
            }
            else
            {
              //删除指定文件
              File.Delete(i.FullName);        
            }
        }
    }
    catch (Exception e)
    {
          throw;
    }
}

public static void copyFile()
      {
          String sourcePath = "原文件路径";
          String targetPath = "目标路径";
          bool isrewrite = true; // true=覆盖已存在的同名文件,false则反之
          System.IO.File.Copy(sourcePath, targetPath, isrewrite);
       }