query_info_async
Description:
public virtual async FileInfo query_info_async (string attributes, FileQueryInfoFlags flags, int io_priority = DEFAULT, Cancellable? cancellable = null) throws Error
  
  Asynchronously gets the requested information about specified this.
The result is a FileInfo object that contains key-value attributes (such as type or size for the file).
For more details, see query_info which is the synchronous version of this call.
When the operation is finished, callback will be called. You can then call query_info_async.end
       to get the result of the operation.
Example: FileInfo, async:
public static int main (string[] args) {
	if (args.length != 2) {
		print ("%s FILE\n", args[0]);
		return 0;
	}
	MainLoop loop = new MainLoop ();
	File file = File.new_for_commandline_arg (args[1]);
	file.query_info_async.begin ("standard::icon", 0, Priority.DEFAULT, null, (obj, res) => {
		try {
			FileInfo info = file.query_info_async.end (res);
			Icon icon = info.get_icon ();
			print ("%s\n", icon.to_string ());
		} catch (Error e) {
			print ("Error: %s\n", e.message);
		}
		loop.quit ();
	});
	loop.run ();
	return 0;
}valac --pkg gio-2.0 GLib.File.query_info_async.valaParameters:
| this | input File | 
| attributes | an attribute query string | 
| flags | a set of FileQueryInfoFlags | 
| io_priority | the I/O priority of the request | 
| cancellable | optional Cancellable object, null to ignore | 
| callback | a TaskReadyCallback to call when the request is satisfied | 
| user_data | the data to pass to callback function |