Question

我有一个带有静态方法的类（用于运行计算隔离）

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));
  }

我正在另一堂课中实例化……

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)

如何从静态的解码配置文件图像访问tempPath成员。 -感谢阅读。

Answer 1

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

回调参数必须是顶级函数，而不是类的闭包，实例或静态方法。

特别注意

不是类的...或静态方法

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


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

class ResizeImage {

  ResizeImage(this.tempPath) {
     ...
  }

}

Flutter：如何在同一类的静态方法中访问成员

1 个答案: