pub type VNRequestProgressHandler = *mut DynBlock<dyn Fn(NonNull<VNRequest>, c_double, *mut NSError)>;Available on crate features
VNRequest and block2 only.Expand description
A block that is executed at intervals during the processing of a request.
Parameter request: The VNRequest that has been completed. The results of the request, if no error was encountered, are populated in the results array of the request.
Parameter fractionCompleted: When possible the request will report its progress between 0.0 and 1.0. If the requests indeterminate property is set, then this value is undefined.
Parameter error: The error that caused the request to fail, or nil if completed successfully.
The results in the request can be populated with partial results. The progressHandler can be called on a different dispatch queue than what the request was initiated from.
See also Apple’s documentation