Question

I want to let user to choose a directory for saving a file. but how to make sure the url is a directory not a file?

NSOpenPanel* panel = [NSOpenPanel openPanel];
[panel setCanChooseDirectories:YES];
[panel setCanCreateDirectories:YES];

[panel beginSheetModalForWindow:self.window completionHandler:^(NSInteger result){
    if (result == NSFileHandlingPanelOKButton) {
        NSArray* urls = [panel URLs];
        for (NSURL *url in urls) {
            //here how to judge the url is a directory or a file
        }
    }
}];

Answer 1

// First, check if the URL is a file URL, as opposed to a web address, etc.
if (url.isFileURL) {
  BOOL isDir = NO;
  // Verify that the file exists 
  // and is indeed a directory (isDirectory is an out parameter)
  if ([[NSFileManager defaultManager] fileExistsAtPath: url.path isDirectory: &isDir]
      && isDir) {
    // Here you can be certain the url exists and is a directory
  }
}