dart - Flutter:如何在同一个类的静态方法中访问成员

Question

我有一个带有静态方法的类(运行计算隔离)

class ResizeImage {

  ResizeImage(this.tempPath) {
    sTempPath = tempPath;

    print('main()resizeMyProImage.dart...IN CLASS.........imgFile tempPath: '+tempPath);
    print('main()resizeMyProImage.dart...IN CLASS.........imgFile sTempPath: '+sTempPath);
  }

  String tempPath;
  static String sTempPath

....

  static File decodeProfileImage(File imageFile) {
// get sTempPath here...


    print('decodeProfileImage...decodeImage.dart...IN CLASS.......well.tempPath......hit with: '+sTempPath);

//    Im.Image image = Im.decodeImage(imageFile.readAsBytesSync());
//    Im.Image smallerImage = Im.copyResize(image, 150); // choose the size here, it will maintain aspect ratio
//    return new File(sTempPath+'thumbnail.jpg')
//      ..writeAsBytesSync(Im.encodeJpg(smallerImage, quality: 85));
  }

我在另一个类中像这样实例化...

ResizeImage resizeImage = new ResizeImage(tempPath);
      print('uploadFile >>>>>>>>>>>>>>>>>>>>>....hit begin 000 resizeImage.tempPath: '+resizeImage.tempPath);

      File myFile;
      if (isProfilePic) myFile = (await resizeImage.resizeMyProImage(file));

错误:

Isolate (389190561) 'main.dart:_spawn()' exited with an error
E/flutter ( 2369): [ERROR:flutter/shell/common/shell.cc(181)] Dart Error: Unhandled exception:
E/flutter ( 2369): Invalid argument(s)
E/flutter ( 2369): #0      _StringBase.+ (dart:core/runtime/libstring_patch.dart:246:57)

如何从静态 decodeProfileImage 访问 tempPath 成员。 -感谢阅读。

Answer 1

编辑:

这已经改变了，回调可以是静态方法:参见https://api.flutter.dev/flutter/foundation/ComputeCallback.html .

我没有尝试过，也没有找到相关的更新日志。我希望文档是正确的。

原创

https://docs.flutter.io/flutter/foundation/compute.html

The callback argument must be a top-level function, not a closure or an instance or static method of a class.

特别注意

not a ... or static method of a class

Future doSomethingInIsolate() async {
  var result = await compute(decodeProfileImage, data);
}


File decodeProfileImage(File imageFile) {
  var resize = ResizeImage();
  resize...
}

class ResizeImage {

  ResizeImage(this.tempPath) {
     ...
  }

}