Flutter 1.12.13+hotfix.5 • channel stable

Because every version of flutter_test from sdk depends on image 2.1.4 and flutter_luban 0.1.9+2 depends on image ^2.1.9, flutter_test from sdk is incompatible with flutter_luban 0.1.9+2.

I have list of files like (sample1.jpg, sample2.jpg, sample3.jpg, ...). I want to compress those files before upload it. I plan to use Dio to upload it. Can you help me the code to do that?

[ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: Exception: FileSystemException: Cannot open file, path = '/data/user/0/com.example.im_flutter/cache/Android.jpg/img_1571561019173.jpg' (OS Error: No such file or directory, errno = 2)

Hello, I am wondering if we could support flutter web.

This could be done by make the input and output images data type uint8list. Meaning add field Uint8list dataBytes to CompressObject() function and Luban.compressImage() return Uint8list.

Thanks

I am developing a Flutter desktop app for macOS. I have 100 images that I need to compress. If I call the compress function inside a for loop, the whole UI freezes and crashes the app.

Compiler message: ../../../Desktop/flutter/.pub-cache/hosted/pub.flutter-io.cn/zoomable_image-1.3.1/lib/src/zoomable_image.dart:174:30: Error: The argument type 'void Function(ImageInfo, bool)' can't be assigned to the parameter type 'ImageStreamListener'.

• 'ImageInfo' is from 'package:flutter/src/painting/image_stream.dart' ('../../../Desktop/flutter/packages/flutter/lib/src/painting/image_stream.dart').
• 'ImageStreamListener' is from 'package:flutter/src/painting/image_stream.dart' ('../../../Desktop/flutter/packages/flutter/lib/src/painting/image_stream.dart'). _imageStream.addListener(_handleImageLoaded); ^ ../../../Desktop/flutter/.pub-cache/hosted/pub.flutter-io.cn/zoomable_image-1.3.1/lib/src/zoomable_image.dart:186:33: Error: The argument type 'void Function(ImageInfo, bool)' can't be assigned to the parameter type 'ImageStreamListener'.
• 'ImageInfo' is from 'package:flutter/src/painting/image_stream.dart' ('../../../Desktop/flutter/packages/flutter/lib/src/painting/image_stream.dart').
• 'ImageStreamListener' is from 'package:flutter/src/painting/image_stream.dart' ('../../../Desktop/flutter/packages/flutter/lib/src/painting/image_stream.dart'). _imageStream.removeListener(_handleImageLoaded); ^ Target kernel_snapshot failed: Exception: Errors during snapshot creation: null Failed to build bundle. Error launching application on iPhone 11 Pro Max.

您好！ 请教一下，这段代码是如何通过递归减少文件size的，level这个参数的作用是什么？ 谢谢指点 static void _compressPng({ Image image, File file, level: 9, targetSize, }) { var im = encodePng(image, level: level); var tempImageSize = Uint8List.fromList(im).lengthInBytes; if (tempImageSize / 1024 < targetSize) { _small2LargeCompressImage( image: image, file: file, targetSize: targetSize, isJpg: false, ); return; } file.writeAsBytesSync(im); } }

不知道是不是我的代码有问题, 图片是 1920*1080的屏幕截图 Future getImage() async { await ImagePicker.pickImage(source: ImageSource.gallery).then((file) async { CompressObject compressObject = CompressObject( imageFile: file, //image path: file.parent.absolute.path, ); return Luban.compressImage(compressObject); }).then((_path) { setState(() { imgUrlList.clear(); imgUrlList.add(_path); }); }); }

By removing type casting I was able to run this correctly.

Before I was getting the following error. Flutter 2.0.4

Exception has occurred.
_CastError (type '(CompressObject) => String?' is not a subtype of type '(dynamic) => FutureOr<String>' in type cast)

Code & error:

    final compressionList = <CompressObject>[];
    for (final image in images) {
      compressionList.add(
        CompressObject(
          imageFile: File(image.path),
          quality: 30,
          step: 9,
        ),
      );
    }

    final compressedImages = <XFile>[];
    await Luban.compressImageList(compressionList).then((paths) {  // <= Exception here
      for (final path in paths) {
        if (path != null) {
          compressedImages.add(XFile(path));
        }
      }
    });

E/flutter (26892): [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: Null check operator used on a null value
E/flutter (26892): #0      Luban._lubanCompress (package:flutter_luban/src/flutter_luban.dart:91:22)
E/flutter (26892): #1      Luban._lubanCompressList.<anonymous closure> (package:flutter_luban/src/flutter_luban.dart:44:19)
E/flutter (26892): #2      List.forEach (dart:core-patch/growable_array.dart:416:8)
E/flutter (26892): #3      Luban._lubanCompressList (package:flutter_luban/src/flutter_luban.dart:43:13)
E/flutter (26892): #4      _IsolateConfiguration.applyAndTime.<anonymous closure>
package:flutter/…/foundation/_isolates_io.dart:107
E/flutter (26892): #5      Timeline.timeSync (dart:developer/timeline.dart:157:22)
E/flutter (26892): #6      _IsolateConfiguration.applyAndTime
package:flutter/…/foundation/_isolates_io.dart:105
E/flutter (26892): #7      _spawn
package:flutter/…/foundation/_isolates_io.dart:126

Unhandled Exception: Exception: FileSystemException: Cannot open file, path = '/data/user/0/com.example.compress_image_demo/cache/scaled_91926534-c6ab-492c-9318-98d38850098b1214548903574526107.jpg/img_1650868354290.jpg' (OS Error: Not a directory, errno = 20)

static List<String?> _lubanCompressList(List objects) { var results = []; objects.forEach((_o) { results.add(_lubanCompress(_o)); }); return results as List<String?>; }

The above method was causing that error: Had to change to the below and resolved the error

static List<String?> _lubanCompressList(List objects) { var results = []; objects.forEach((_o) { results.add(_lubanCompress(_o)); }); return (results as List<dynamic?>).cast<String?>(); }

This is the only package right now that support image compression without needing native code,

I made fast refactoring to support compression of raw bytes, because on browsers it's impossible to read and write directly on file system

CompressObject compressObject = CompressObject( imageFile: File('/storage/emulated/0/fluttera/349.jpg'), path: '/storage/emulated/0/fluttera/15882605447.jpg', quality: 80, step: 9, mode: CompressMode.AUTO ); var path =await (Luban.compressImage(compressObject));

[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: Exception: FileSystemException: Cannot open file, path = '/storage/emulated/0/fluttera/15882605447.jpg/img_1588261036457.jpg' (OS Error: No such file or directory, errno = 2)

用的最新版的flutter 和Dart ,图片是本地已经存在的,不知道为什么会提示找不到 报错