参考链接:https://www.jb51.net/article/58711.htm
    本文实例讲述了C#实现获取磁盘空间大小的方法。分享给大家供大家参考。具体实现方法如下：
    方法一：利用System.IO.DriveInfo.GetDrives方法来获取

    1. ///   
    2. /// 获取指定驱动器的空间总大小(单位为B) 
    3. ///   
    4. ///  只需输入代表驱动器的字母即可 （大写） 
    5. ///    
    6. public static long GetHardDiskSpace(string str_HardDiskName) 
    7. { 
    8.     long totalSize= new long(); 
    9.     str_HardDiskName=str_HardDiskName +":\\"; 
    10.     System.IO.DriveInfo[] drives = System.IO.DriveInfo.GetDrives(); 
    11.     foreach (System.IO.DriveInfo drive in drives) 
    12.     { 
    13.  if (drive.Name == str_HardDiskName) 
    14.  {
    15.      totalSize = drive.TotalSize / (1024 * 1024 * 1024); 
    16.  } 
    17.     } 
    18.     return totalSize; 
    19. }
    20. ///   
    21. /// 获取指定驱动器的剩余空间总大小(单位为B) 
    22. ///   
    23. ///  只需输入代表驱动器的字母即可  
    24. ///    
    25. public static long GetHardDiskFreeSpace(string str_HardDiskName) 
    26. { 
    27.     long freeSpace = new long(); 
    28.     str_HardDiskName = str_HardDiskName + ":\\"; 
    29.     System.IO.DriveInfo[] drives = System.IO.DriveInfo.GetDrives(); 
    30.     foreach (System.IO.DriveInfo drive in drives) 
    31.     { 
    32.  if (drive.Name == str_HardDiskName) 
    33.  {
    34.      freeSpace = drive.TotalFreeSpace / (1024 * 1024 * 1024); 
    35.  } 
    36.     } 
    37.     return freeSpace; 
    38. }

    方法二：利用ManagementClass(“Win32_LogicalDisk”)来获取

    List<Dictionary<string, string>> diskInfoDic = new List<Dictionary<string, string>>();
ManagementClass diskClass = new ManagementClass("Win32_LogicalDisk");
ManagementObjectCollection disks = diskClass.GetInstances();
foreach(ManagementObject disk in disks)
{
 Dictionary<string, string> diskInfo = new Dictionary<string, string>();
 try
 {
     // 磁盘名称
     diskInfo["Name"] =disk["Name"].ToString();
     // 磁盘描述
     diskInfo["Description"]=disk["Description"].ToString();
     // 磁盘总容量，可用空间，已用空间
     if (System.Convert.ToInt64(disk["Size"]) > 0)
     {
          long totalSpace = System.Convert.ToInt64(disk["Size"]) / MB;
          long freeSpace = System.Convert.ToInt64(disk["FreeSpace"]) / MB;
          long usedSpace = totalSpace - freeSpace;
           diskInfo["totalSpace"]=totalSpace.ToString();
          diskInfo["usedSpace"]=usedSpace.ToString();
          diskInfo["freeSpace"]=freeSpace.ToString();
     }
     diskInfoDic.Add(diskInfo);
 }
 catch(Exception ex)
 {

 }
}