How to determine if there is enough space on a remote drive to write a file using C #?

Question

How to determine if there is enough space on a remote drive to download a file using C # in .Net?

Answer 1

There are two possible solutions.

• Call Win32 function GetDiskFreeSpaceEx. Here is an example program:

  internal static class Win32
  {
      [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
      internal static extern bool GetDiskFreeSpaceEx(string drive, out long freeBytesForUser, out long totalBytes, out long freeBytes);
  
  }
  
  class Program
  {
      static void Main(string[] args)
      {
          long freeBytesForUser;
          long totalBytes;
          long freeBytes;
  
          if (Win32.GetDiskFreeSpaceEx(@"\\prime\cargohold", out freeBytesForUser, out totalBytes, out freeBytes)) {
              Console.WriteLine(freeBytesForUser);
              Console.WriteLine(totalBytes);
              Console.WriteLine(freeBytes);
          }
      }
  }
  

• Use the system management interface. There is another answer in this post that describes this. This method is really designed for use in scripting languages ​​such as PowerShell. He does a lot of fluff to get the right object. Ultimately, I suspect this method boils down to calling GetDiskFreeSpaceEx.

, Windows #, , Win32. .NET 100% Win32 API. .NET, API Win32. Win32 .NET . API Win32.

Answer 2

WMI

using System.Management;

// Get all the network drives (drivetype=4)
SelectQuery query = new SelectQuery("select Name, VolumeName, FreeSpace from win32_logicaldisk where drivetype=4");
ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
foreach (ManagementObject drive in searcher.Get())
{
    string Name = (string)drive["Name"];
    string VolumeName = (string)drive["VolumeName"];
    UInt64 freeSpace = (UInt64)drive["FreeSpace"];
}

() http://www.dreamincode.net/code/snippet1576.htm

Answer 3

?

, DriveInfo.

    DriveInfo info = new DriveInfo("X:");

    info.AvailableFreeSpace;

DriveInfo , , (UNC), , .

Answer 4

, GetDiskFreeSpaceEx UNC, , UNC :

GetDiskFreeSpaceEx UNC, ... , , , - UNC .

public class DriveWrapper
{                    
    [StructLayout(LayoutKind.Sequential)]
    public struct NETRESOURCEA
    {
        public int dwScope;
        public int dwType;
        public int dwDisplayType;
        public int dwUsage;
        [MarshalAs(UnmanagedType.LPStr)]
        public string lpLocalName;
        [MarshalAs(UnmanagedType.LPStr)]
        public string lpRemoteName;
        [MarshalAs(UnmanagedType.LPStr)]
        public string lpComment;
        [MarshalAs(UnmanagedType.LPStr)]
        public string lpProvider;
        public override String ToString()
        {
            String str = "LocalName: " + lpLocalName + " RemoteName: " + lpRemoteName
                  + " Comment: " + lpComment + " lpProvider: " + lpProvider;
            return (str);
        }
    }

    [DllImport("mpr.dll")]
    public static extern int WNetAddConnection2A(
          [MarshalAs(UnmanagedType.LPArray)] NETRESOURCEA[] lpNetResource,
          [MarshalAs(UnmanagedType.LPStr)] string lpPassword,
          [MarshalAs(UnmanagedType.LPStr)] string UserName,
          int dwFlags);       
    [DllImport("mpr.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
    private static extern int WNetCancelConnection2A(
          [MarshalAs(UnmanagedType.LPStr)]
        string lpName,
          int dwFlags,
          int fForce
          );

    public int GetDriveSpace(string shareName, string userName, string password)
    {
        NETRESOURCEA[] n = new NETRESOURCEA[1];
        n[0] = new NETRESOURCEA();

        n[0].dwScope = 0;
        n[0].dwType = 0;
        n[0].dwDisplayType = 0;
        n[0].dwUsage = 0;

        n[0].dwType = 1;

        n[0].lpLocalName = "x:";
        n[0].lpRemoteName = shareName;
        n[0].lpProvider = null;

        int res = WNetAddConnection2A(n, userName, password, 1);

        DriveInfo info = new DriveInfo("x:");
        int space = info.AvailableFreeSpace;

        int err = 0;
        err = WNetCancelConnection2A("x:", 0, 1);

        return space;
    }
}