C#实现获取文件大小并进行比较

 
using System;
using System.io;
 
namespace Kernal
{
    public class FileOPC 
	{
       
        /// <summary>
        /// 获取到文件的大小
        /// </summary>
        /// <param name="fileInfo">文件信息</param>
        /// <returns>返回文件的大小（单位是字节）</returns>
        public static long GetFileSize(FileInfo fileInfo)
        {
            return fileInfo.Length;
        }
 
        /// <summary>
        /// 将文件大小(字节)转换为最适合的显示方式
        /// </summary>
        /// <param name="size">文件字节</param>
        /// <returns>返回转换后的字符串</returns>
        public static string ConvertFileSize(long size)
        {
            string result = "0KB";
            int filelength = size.ToString().Length;
            if (filelength < 4)
                result = size + "byte";
            else if (filelength < 7)
                result = Math.Round(Convert.ToDouble(size / 1024d), 2) + "KB";
            else if (filelength < 10)
                result = Math.Round(Convert.ToDouble(size / 1024d / 1024), 2) + "MB";
            else if (filelength < 13)
                result = Math.Round(Convert.ToDouble(size / 1024d / 1024 / 1024), 2) + "GB";
            else
                result = Math.Round(Convert.ToDouble(size / 1024d / 1024 / 1024 / 1024), 2) + "TB";
            return result;
        }
 
 
        /// <summary>
        /// 将文件大小(字节)统一转换为K为单位
        /// </summary>
        /// <param name="size">文件字节</param>
        /// <returns>返回转换后的字符串</returns>
        public static double ConvertFileSizeToK(long size)
        {
            double result = 0;
            if (size > 0)
            {
                result = Math.Round(Convert.ToDouble(size / 1024d), 2);
            }
            return result;
        }
 
        /// <summary>
        /// 将文件大小(字节)统一转换为M为单位
        /// </summary>
        /// <param name="size">文件字节</param>
        /// <returns>返回转换后的字符串</returns>
        public static double ConvertFileSizeToM(long size)
        {
            double result = 0;
            if (size > 0)
            {
                result = Math.Round(Convert.ToDouble(size / 1024d / 1024), 2);
            }
            return result;
        }
 
        /// <summary>
        /// 将文件大小(字节)统一转换为G为单位
        /// </summary>
        /// <param name="size">文件字节</param>
        /// <returns>返回转换后的字符串</returns>
        public static double ConvertFileSizeToG(long size)
        {
            double result = 0;
            if (size > 0)
            {
                result = Math.Round(Convert.ToDouble(size / 1024d / 1024 / 1024), 2);
            }
            return result;
        }
 
        /// <summary>
        /// 将所有文件与设置的数值比较文件的大小
        /// </summary>
        /// <param name="fileInfo">当前的文件信息</param>
        /// <param name="curSetFileSize">当前设置的文件大小</param>
        /// <returns>返回比较的结果（true:表示满足）</returns>
        public static bool CompareFileSize(FileInfo fileInfo, double curSetFileSize, CompareFileDir compareFileDir)
        {
            bool success = false;
            double curFileSize = FileOPC.ConvertFileSizeToM(fileInfo.Length);
            switch (compareFileDir)
            {
                case CompareFileDir.大于:
                    if (curFileSize > curSetFileSize)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.小于:
                    if (curFileSize < curSetFileSize)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.等于:
                    if (curFileSize == curSetFileSize)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.大于等于:
                    if (curFileSize >= curSetFileSize)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.小于等于:
                    if (curFileSize <= curSetFileSize)
                    {
                        success = true;
                    }
                    break;
                default:
                    break;
            }
 
            return success;
        }
 
        /// <summary>
        /// 比较两个文件的大小
        /// </summary>
        /// <param name="fileInfo">当前的文件信息</param>
        /// <param name="curSetFileSize">当前设置的文件大小</param>
        /// <returns>返回比较的结果（true:表示文件1比文件2大）</returns>
        public static bool CompareTwoFileSize(FileInfo fileInfo1, FileInfo fileInfo2, CompareFileDir compareFileDir)
        {
            bool success = false;
            double curFile1Size = FileOPC.ConvertFileSizeToM(fileInfo1.Length);
            double curFile2Size = FileOPC.ConvertFileSizeToM(fileInfo2.Length);
            switch (compareFileDir)
            {
                case CompareFileDir.大于:
                    if (curFile1Size > curFile2Size)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.小于:
                    if (curFile1Size < curFile2Size)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.等于:
                    if (curFile1Size == curFile2Size)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.大于等于:
                    if (curFile1Size >= curFile2Size)
                    {
                        success = true;
                    }
                    break;
                case CompareFileDir.小于等于:
                    if (curFile1Size <= curFile2Size)
                    {
                        success = true;
                    }
                    break;
                default:
                    break;
            }
 
            return success;
        }
 
        
    }//Class_end
 
    //比较文件的方向
    public enum CompareFileDir
    {
        大于,         //大于
        小于,         //小于
        等于,         //等于
        大于等于,     // 大于等于
        小于等于,     //大于等于
    }
}

using Kernal;