This package provides a Dart abstraction over Windows metadata files, making it possible to load them and build Dart FFI interop libraries from the results.

pub package Language Code Coverage


Architecture diagram

Usage (Windows Runtime)

A simple example: loading the IAsyncInfo interface and emitting the Dart equivalent file.

import 'package:winmd/winmd.dart';

final type = 'Windows.Foundation.IAsyncInfo';
final typeDef = MetadataStore.getMetadataForType(type);
final projection = TypeBuilder.projectWindowsType(typeDef);
final dartClass = TypePrinter.printType(projection);

final outputFilename = type.split('.').last;
final outputFile =

print('Writing:    ${outputFile.path}');

Usage (Win32)

Load all the methods from the GDI namespace and print out some metadata.

import 'package:winmd/winmd.dart';

void main() {
  // Load WinMD metadata for Win32, as produced by the following utility:
  final scope = MetadataStore.getScopeForFile('Windows.Win32.winmd');

  // Find the GDI API namesapce
  final gdiApi =
      scope.typeDefs.firstWhere((type) => type.typeName.endsWith('Gdi.Apis'));

  // Sort the functions alphabetically
  final sortedMethods = gdiApi.methods
    ..sort((a, b) => a.methodName.compareTo(b.methodName));

  // Find a specific function
  const funcName = 'AddFontResourceW';
  final method = sortedMethods.firstWhere((m) => m.methodName == funcName);

  // Print out some information about it
  print('This method is token #${method.token}');

  final params = method.parameters
      .map((param) => '${param.typeIdentifier.nativeType} ${!}')
      .join(', ');
  print('The parameters are:\n$params');

Features and bugs

Please file feature requests and bugs at the issue tracker.


Support for working with Windows Metadata, as defined in the ECMA-335 specification. [...]