Flutter版合成大西瓜

#首先把Flutter仓库地址换成清华源到镜像地址，加速下载
git remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/flutter-sdk.git

#切换分支
flutter channel dev

#更新sdk
flutter upgrade

#开启web，desktop支持
flutter config --enable-web
flutter config --enable-macos-desktop

dependencies:
  flutter:
    sdk: flutter
  pedantic: ^1.9.2

#analysis_options.yaml
include: package:pedantic/analysis_options.yaml

/// Returns a round cropped copy of [src].
Image copyCropCircle(
  Image src, {
  int radius,
  Point center,
}) {
  int min(num x, num y) => (x < y ? x : y).toInt();
  final defaultRadius = min(src.width, src.height) ~/ 2;
  radius ??= defaultRadius;
  center ??= Point(src.width ~/ 2, src.height ~/ 2);
  // Make sure center point is within the range of the src image
  center.x = center.x.clamp(0, src.width - 1).toInt();
  center.y = center.y.clamp(0, src.height - 1).toInt();
  radius = radius < 1 ? defaultRadius : radius;

  final tlx = center.x.toInt() - radius; //topLeft.x
  final tly = center.y.toInt() - radius; //topLeft.y

  var dst = Image(
    radius * 2,
    radius * 2,
    channels: Channels.rgba,
    iccp: src.iccProfile,
  );

  for (var yi = 0, sy = tly; yi < radius * 2; ++yi, ++sy) {
    for (var xi = 0, sx = tlx; xi < radius * 2; ++xi, ++sx) {
      if ((xi - radius) * (xi - radius) + (yi - radius) * (yi - radius) <=
          radius * radius) {
        dst.setPixel(xi, yi, src.getPixelSafe(sx, sy));
      }
    }
  }

  return dst;
}

//file/file_io.dart
import 'dart:io';
import 'dart:typed_data';

import 'package:path_provider/path_provider.dart';

class FileTool {
  static Future<Uint8List> read(String path) async {
    final directory = await getApplicationDocumentsDirectory();
    var file = File(directory.path + path);
    if (!await file.exists()) return null;
    return await file.readAsBytes();
  }

  static Future<void> write(String path, Uint8List bytes) async {
    final directory = await getApplicationDocumentsDirectory();
    var file = File(directory.path + path);
    if (!await file.exists()) {
      file = await file.create(recursive: true);
    }
    await file.writeAsBytes(bytes, flush: true);
  }

  static Future<void> delete(String path) async {
    final directory = await getApplicationDocumentsDirectory();
    var file = File(directory.path + path);
    if (!await file.exists()) return;
    file.deleteSync();
  }
}

//file/file_web.dart
import 'dart:typed_data';

import '../hive_tool.dart';
import '../image/ui_image_tool.dart';

class FileTool {
  static Future<Uint8List> read(String path) async {
    if (!HiveTool().inited) await HiveTool().init();
    final value = await HiveTool().box.get(path);
    if (value == null) return null;
    return (value as String).toBytes();
  }

  static Future<void> write(String path, Uint8List bytes) async {
    if (!HiveTool().inited) await HiveTool().init();
    await HiveTool().box.put(path, bytes.toBase64());
  }

  static Future<void> delete(String path) async {
    if (!HiveTool().inited) await HiveTool().init();
    await HiveTool().box.delete(path);
  }
}

//file_tool.dart
export 'file/file_io.dart' if (dart.library.html) 'file/file_web.dart';

dependencies:
  ...
  flutter_launcher_icons: ^0.8.1

flutter_icons:
  image_path: "logo.png"
  android: true
  ios: true

flutter build web --release

flutter build apk --split-per-abi