How to achieve the folder size property in c# using wql?

Question

I want to display the folder and file size in list view which is placed in my form.

Is it possible to achieve the folder size at the whole(including sub folders and files) and display it from remote computer?

With the following code, i can get the original file size, but am not all getting original folder size. Instead of it, am getting folder size as 0kb.

ManagementScope ManagementScope1 = new ManagementScope(string.Format("\\\\{0}\\root\\cimv2", strIP), options);
ManagementScope1.Connect();
ObjectGetOptions objectGetOptions = new ObjectGetOptions();
ObjectQuery obq1 = new ObjectQuery("Associators of {Win32_Directory.Name='D:'} Where ResultRole = PartComponent ");
ManagementObjectSearcher searcher1 = new ManagementObjectSearcher(ManagementScope1, obq1);

foreach (ManagementObject ManagementObject2 in searcher1.Get())
{
    lvData[0] = ManagementObject2["FileName"].ToString();
    lvData[1] = formatSize(Convert.ToInt64(ManagementObject2["FileSize"]));
    ListViewItem lvItem = new ListViewItem(lvData, 0);
    lvFiles.Items.Add(lvItem);
}

formatSize() as follows :

protected string formatSize(Int64 lSize)
{
        //Format number to KB
     string stringSize = "";
     NumberFormatInfo myNfi = new NumberFormatInfo();

     Int64 lKBSize = 0;

     if (lSize < 1024)
     {
         if (lSize == 0)
         {
            //zero byte
            stringSize = "0";
         }
         else
         {
            //less than 1K but not zero byte
            stringSize = "1";
         }
      }
      else
      {
            //convert to KB
            lKBSize = lSize / 1024;
            //format number with default format
            stringSize = lKBSize.ToString("n", myNfi);
            //remove decimal
            stringSize = stringSize.Replace(".00", "");
      }
      return stringSize + " KB";
 }

I also tried with this link, but i fail because of Object reference not set to an instance of an object error when i used as,

FolderSize += (UInt64)ManagementObject2["FileSize"]; 
lvData[1] = formatSize(Convert.ToInt64 (FolderSize));

So kindly someone help me to overcome this issue.

Answer 1

The problem, as @rene pointed out, is that folders don't actually have a size. They are containers. To get the total size you would have to enumerate all the files in the directory and subdirectories to calculate it.

Excerpt from MSDN

FileSize

Data type: uint64

Access type: Read-only

Size of the file system object, in bytes. Although folders possess a FileSize property, the value 0 is always returned. To determine the size of a folder, use the FileSystemObject or add up the size of all the files stored in the folder. For more information about using uint64 values in scripts, see Scripting in WMI.

The easiest way, arguably, is to use the DirectoryInfo class, UNC paths and some LINQ.

var folder = @"\\MachineOrIp\c$\Temp";

        var directory = new DirectoryInfo(folder);
        var totalSize = directory.EnumerateFiles("*.*", SearchOption.AllDirectories).Sum(file => file.Length);

        Console.WriteLine("{0} - {1} Bytes", folder, totalSize);

This will allow you get get the "total size", in bytes, for a top-level folder.

Answer 2

There is no size for a folder, a folder is just a container for files, the size of the files determine the foldersize.

To get the overall foldersize you can do an approximation by finding the disksize and the freespace and then subtracting those two which will give you the folder size.

On a background scan the folders with CIM_Directory and CIM_DataFile. You can call the scan method with a managementscope and a drive letter (D:)

I did run in it from a ThreadPool thread like so:

ManagementScope ManagementScope1 = new ManagementScope();
ManagementScope1.Connect();
ThreadPool.QueueUserWorkItem((que) => { scan(ManagementScope1, "D:"); });

Iterate over folders with WMI

private void scan(ManagementScope scope, string drive)
{
var disk = scope.Device(drive).GetEnumerator();
if (!disk.MoveNext())
{
    Add(String.Format("{0} drive not found",drive),0);
    return;
}

Add(drive, disk.Current.Size() - disk.Current.FreeSpace());

// iterate over root Folders
foreach (var folder in scope.Folder(drive))
{
    ulong totalsize = 0;
    try
    {
        // iterate over the files
        foreach (var file in scope.File(
                    drive,
                    folder.Path(),
                    folder.FileName()))
        {
            totalsize += file.FileSize();
        }
        // iterate over all subfolders
        foreach (var subfolder in scope.SubFolder(drive
                    , folder.Path()
                    , folder.FileName()))
        {
            // iterate over files within a folder
            foreach (var file in scope.File(
                    drive,
                    subfolder.Path(),
                    subfolder.FileName()))
            {
                totalsize += file.FileSize();
            }
        }
    }
    catch (Exception exp)
    {
        Debug.WriteLine(exp.Message);
    }
    Add(folder.Name(), totalsize);  
}
}

Extension methods

The original code became close to unmaintainable so I implemented Extension methods for ManagementScope and ManagementBaseObject.

public static class ManagementObjectExtensions
{
    const string WQL_DEVICE = "Select Size,FreeSpace from Win32_LogicalDisk where Deviceid='{0}'";
    const string WQL_FOLDER = "Select Path, Filename, Name from CIM_Directory where Drive='{0}' and path='\\\\' and system = false and hidden = false and readable = true";
    const string WQL_SUBFOLDER = "Select Path, Filename from CIM_Directory where Drive='{0}' and path like '{1}{2}\\\\%' and system = false and hidden = false and readable = true";
    const string WQL_FILE = "Select FileSize from CIM_DataFile where Drive='{0}' AND Path = '{1}{2}\\\\' ";

    // internal helper to get an enumerable collection from any WQL
    private static ManagementObjectCollection GetWqlEnumerator(this ManagementScope scope, string wql, params object[] args)
    {
        return new ManagementObjectSearcher(
            scope,
            new ObjectQuery(
                String.Format(wql, args)))
            .Get();
    }

    public static ManagementObjectCollection Device(this ManagementScope scope, params object[] args)
    {
        return scope.GetWqlEnumerator(WQL_DEVICE, args);
    }

    public static ManagementObjectCollection Folder(this ManagementScope scope, params object[] args)
    {
        return scope.GetWqlEnumerator(WQL_FOLDER, args);
    }

    public static ManagementObjectCollection SubFolder(this ManagementScope scope, params object[] args)
    {
        return scope.GetWqlEnumerator(WQL_SUBFOLDER, args);
    }

    public static ManagementObjectCollection File(this ManagementScope scope, params object[] args)
    {
        return scope.GetWqlEnumerator(WQL_FILE, args);
    }

    public static string Path(this ManagementBaseObject mo)
    {
        return mo["Path"].ToString().Replace("\\","\\\\");
    }

    public static string Name(this ManagementBaseObject mo)
    {
        return mo["Name"].ToString();
    }

    public static string FileName(this ManagementBaseObject mo)
    {
        return mo["FileName"].ToString();
    }

    public static ulong FreeSpace(this ManagementBaseObject mo)
    {
        return (ulong)mo["FreeSpace"];
    }

    public static ulong Size(this ManagementBaseObject mo)
    {
        return (ulong) mo["Size"];
    }

    public static ulong FileSize(this ManagementBaseObject mo)
    {
        return (ulong) mo["FileSize"];
    }
}

helper for adding items to the Listview

This little helper handles switching to the UI thread if needed

// UI Thread safe helper for adding an item
private void Add(string name, ulong size)
{
    if (this.listView1.InvokeRequired)
    {
        this.listView1.Invoke(new MethodInvoker(() => Add(name, size)));
    }
    else
    {
        var lvi = new ListViewItem(name);
        lvi.SubItems.Add(size.ToString());

        this.listView1.Items.Add(lvi);
    }
}

I looked up a path selection issue in this answer from RRUZ