argument_must_be_native

Argument to 'Native.addressOf' must be annotated with @Native

The analyzer produces this diagnostic when the argument passed to Native.addressOf isn't annotated with the Native annotation.

The following code produces this diagnostic because the argument to addressOf is a string, not a field, and strings can't be annotated:

import 'dart:ffi';

@Native<Void Function()>()
external void f();

void g() {
  print(Native.addressOf('f'));
}

The following code produces this diagnostic because the function f is being passed to addressOf but isn't annotated as being Native:

import 'dart:ffi';

external void f();

void g() {
  print(Native.addressOf<NativeFunction<Void Function()>>(f));
}

If the argument isn't either a field or a function, then replace the argument with a field or function that's annotated with Native:

import 'dart:ffi';

@Native<Void Function()>()
external void f();

void g() {
  print(Native.addressOf<NativeFunction<Void Function()>>(f));
}

If the argument is either a field or a function, then annotate the field of function with Native:

import 'dart:ffi';

@Native<Void Function()>()
external void f();

void g() {
  print(Native.addressOf<NativeFunction<Void Function()>>(f));
}

Unless stated otherwise, the documentation on this site reflects Dart 3.8.0. Page last updated on 2025-05-08. View source or report an issue.