getResourceValue(_:forKey:)
Returns the value of the resource property for the specified key.
Declaration
func getResourceValue(_ value: AutoreleasingUnsafeMutablePointer<AnyObject?>, forKey key: URLResourceKey) throwsParameters
- value:
The location where the value for the resource property identified by
keyshould be stored. - key:
The name of one of the URL’s resource properties.
Discussion
This method first checks if the URL object already caches the resource value. If so, it returns the cached resource value to the caller. If not, then this method synchronously obtains the resource value from the backing store, adds the resource value to the URL object’s cache, and returns the resource value to the caller.
The type of the returned resource value varies by resource property; for details, see the documentation for the key you want to access.
If this method returns true and the value is populated with nil, it means that the resource property is not available for the specified resource, and that no errors occurred when determining that the resource property was unavailable.
If this method returns false, an error occurred. The object pointer referenced by error is populated with additional information.