downloadByUrl method

Future<String> downloadByUrl(String url, { String? savePath, void onReceiveProgress(int received, int total)?, CancelToken? cancelToken, })

下载指定 URL 到 savePath（可断点续传）；未传 savePath 时落到临时文件，不做 Range 续传。

onReceiveProgress 参数为 (当前文件已下载字节, 当前文件总字节或占位)。

Implementation

Future<String> downloadByUrl(
  String url, {
  String? savePath,
  void Function(int received, int total)? onReceiveProgress,
  CancelToken? cancelToken,
}) async {
  final targetPath =
      savePath ??
      p.join(
        (await _ensureCacheDir()).path,
        '${DateTime.now().millisecondsSinceEpoch}${_extractExt(url)}',
      );
  final ct = cancelToken ?? CancelToken();
  if (savePath == null) {
    await _dio.download(
      url,
      targetPath,
      onReceiveProgress: onReceiveProgress,
      cancelToken: ct,
    );
    return targetPath;
  }
  return _downloadFileWithResume(
    url,
    targetPath,
    cancelToken: ct,
    onFileProgress: (fileNow, totalF) {
      onReceiveProgress?.call(
        fileNow,
        (totalF != null && totalF > 0) ? totalF : fileNow,
      );
    },
  );
}