Question

Got a problem for how to determine file/folder in trash.
There’s some solution on Internet, one of those is FSFindFolder.
which can be used something like this:

FSFindFolder(kUserDomain, kTrashFolderType, true, &trashRef);

but still don’t know how to pass the path of file that I want to determine using this method

Answer 1

The last parameter of FSFindFolder is a FSRef, which can be converted to a CFURLRef and to a NSURL:

FSRef trashRef;
FSFindFolder(kUserDomain, kTrashFolderType, true, &trashRef);
CFURLRef urlRef = CFURLCreateFromFSRef(NULL, &trashRef);
NSURL *trashUrl = CFBridgingRelease(urlRef);
NSString *trashPath = [trashUrl path];
NSLog(@"trash folder: %@", trashPath);

(I have omitted the error checking for sake of brevity. I have also assumed that you use automatic reference counting.)

Now you can check if a given file is in the trash folder:

NSString *theFile = ...; // your file here
NSString *fileInTrash = [trashPath stringByAppendingPathComponent:theFile];
BOOL isInTrash = [[NSFileManager defaultManager] fileExistsAtPath:fileInTrash];
NSLog(@"is in trash: %d", isInTrash);

NOTE: On Mac OS X 10.8, FSFindFolder is deprecated, and you can use the following code to find the trash folder:

NSString *trashPath = [NSSearchPathForDirectoriesInDomains(NSTrashDirectory, NSUserDomainMask, YES) lastObject];