getImageWH method

Future<Rect> getImageWH({ Image? image, String? url, String? localUrl, String? package, ImageConfiguration? configuration, })

get image width height，load error throw exception.（unit px） 获取图片宽高，加载错误会抛出异常.（单位 px） image url network local url , package

Implementation

Future<Rect> getImageWH({
  Image? image,
  String? url,
  String? localUrl,
  String? package,
  ImageConfiguration? configuration,
}) {
  Completer<Rect> completer = Completer<Rect>();
  _listener = ImageStreamListener(
    (ImageInfo info, bool synchronousCall) {
      _imageStream.removeListener(_listener);
      if (!completer.isCompleted) {
        completer.complete(Rect.fromLTWH(
            0, 0, info.image.width.toDouble(), info.image.height.toDouble()));
      }
    },
    onError: (dynamic exception, StackTrace? stackTrace) {
      _imageStream.removeListener(_listener);
      if (!completer.isCompleted) {
        completer.completeError(exception, stackTrace);
      }
    },
  );

  if (image == null &&
      (url == null || url.isEmpty) &&
      (localUrl == null || localUrl.isEmpty)) {
    return Future.value(Rect.zero);
  }
  Image? img = image;
  if (img == null) {
    img = (url != null && url.isNotEmpty)
        ? Image.network(url)
        : Image.asset(localUrl!, package: package);
  }
  _imageStream = img.image.resolve(configuration ?? ImageConfiguration());
  _imageStream.addListener(_listener);
  return completer.future;
}