flutter - 无法将文件保存到文档目录 IOS Flutter

Question

我试图测试文件下载并保存到文档目录。该代码适用于 Android，但在 IOS 上失败。这是代码：

var dir = await getApplicationDocumentsDirectory();
var documentName = "";
documentName = "testname.pdf";
var storePath = "${dir.path}/$documentName";
var errorOccurred = false;
try {
  await dio.download(url, storePath, onReceiveProgress: (rec, total) {
    print("Rec: $rec , Total: $total");
    _setState(() {
      downloading = true;
      progressString = ((rec / total) * 100).toStringAsFixed(0) + "%";
    });
  });
} catch (e) {
  print(e);
}

错误如下：

异常：PlatformException（file_not_found，找不到文件：'/../Devices/3D122270-E919-455D-AF3F-F048EC32CBB7/data/Containers/Data/Application/1262A294-59DC-47A5-B5A6-24FBAD9D53CA/Library/Caches/testname .pdf'，空，空）

我在模拟器上测试