Working with storage volumes

In AIR 2, you can detect when mass storage volumes are mounted or unmounted. The StorageVolumeInfo class defines a singleton storageVolumeInfo object. The StorageVolumeInfo.storageVolumeInfo object dispatches a storageVolumeMount event when a storage volume is mounted. And it dispatches a storageVolumeUnmount event when a volume is unmounted. The StorageVolumeChangeEvent class defines these events.

Note: On modern Linux distributions, the StorageVolumeInfo object only dispatches storageVolumeMount and storageVolumeUnmount events for physical devices and network drives mounted at particular locations.

The storageVolume property of the StorageVolumeChangeEvent class is a StorageVolume object. The StorageVolume class defines basic properties of the storage volume:

drive —The volume drive letter on Windows ( null on other operating systems)
fileSystemType —The type of file system on the storage volume (such as "FAT", "NTFS", "HFS", or "UFS")
isRemoveable —Whether a volume is removable ( true) or not ( false)
isWritable —Whether a volume is writable ( true) or not ( false)
name —The name of the volume
rootDirectory —A File object corresponding to the root directory of the volume

The StorageVolumeChangeEvent class also includes a rootDirectory property. The rootDirectory property is a File object referencing the root directory of the storage volume that has been mounted or unmounted.

The storageVolume property of the StorageVolumeChangeEvent object is undefined ( null) for an unmounted volume. However you can access the rootDirectory property of the event.

The following code outputs the name and file path of a storage volume when it is mounted:

StorageVolumeInfo.storageVolumeInfo.addEventListener(StorageVolumeChangeEvent.STORAGE_VOLUME_MOUNT, onVolumeMount);
function onVolumeMount(event:StorageVolumeChangeEvent):void
{
    trace(event.storageVolume.name, event.rootDirectory.nativePath);
}

The following code outputs the file path of a storage volume when it is unmounted:

StorageVolumeInfo.storageVolumeInfo.addEventListener(StorageVolumeChangeEvent.STORAGE_VOLUME_UNMOUNT, onVolumeUnmount);
function onVolumeUnmount(event:StorageVolumeChangeEvent):void
{
    trace(event.rootDirectory.nativePath);
}

The StorageVolumeInfo.storageVolumeInfo object includes a getStorageVolumes() method. This method returns a vector of StorageVolume objects corresponding to the currently mounted storage volumes. The following code shows how to list the names and root directories of all mounted storage volumes:

var volumes:Vector.<StorageVolume> = new Vector.<StorageVolume>;
volumes = StorageVolumeInfo.storageVolumeInfo.getStorageVolumes();
for (var i:int = 0; i < volumes.length; i++)
{
    trace(volumes[i].name, volumes[i].rootDirectory.nativePath);
}

Note: On modern Linux distributions, the getStorageVolumes() method returns objects corresponding to physical devices and network drives mounted at particular locations.

The File.getRootDirectories() method lists the root directories (see Pointing to the file system root. However, the StorageVolume objects (enumerated by the StorageVolumeInfo.getStorageVolumes() method) provides more information about the storage volumes.

You can use the spaceAvailable property of the rootDirectory property of a StorageVolume object to get the space available on a storage volume. (See Determining space available on a volume.)