If you call the phone library to tell you, for example, free space on all drives, it will tell you the free space on all installed drives. If the one you are looking for is NOT returned, that is because it is NOT found, so it is NOT mounted. If it is found you can get various details about it, which could well come in useful for the rest of your project.
If you call the phone library to tell you, for example, free space on all drives, it will tell you the free space on all installed drives. If the one you are looking for is NOT returned, that is because it is NOT found, so it is NOT mounted. If it is found you can get various details about it, which could well come in useful for the rest of your project.