flutter-Image加载https图片地址

1.组件类

import 'dart:async';
import 'dart:io';
import 'dart:ui' as ui show instantiateImageCodec, Codec;

import 'package:flutter/foundation.dart';
import 'package:flutter/painting.dart';

class HttpsImage extends ImageProvider<HttpsImage> {
  final String url;
  final double scale;
  final Map<String, String>? headers;

  const HttpsImage(
    this.url, {
    this.scale = 1.0,
    this.headers,
  });

  @override
  Future<HttpsImage> obtainKey(ImageConfiguration configuration) {
    return SynchronousFuture<HttpsImage>(this);
  }

  static final HttpClient _httpClient = HttpClient()
    ..badCertificateCallback = ((X509Certificate cert, String host, int port) => true);

  Future<ui.Codec> _loadAsync(HttpsImage key) async {
    assert(key == this);

    final Uri resolved = Uri.base.resolve(key.url);
    final HttpClientRequest request = await _httpClient.getUrl(resolved);
    headers?.forEach((String name, String value) {
      request.headers.add(name, value);
    });
    final HttpClientResponse response = await request.close();
    if (response.statusCode != HttpStatus.ok) {
      throw Exception('HTTP request failed, statusCode: ${response.statusCode}, $resolved');
    }

    final Uint8List bytes = await consolidateHttpClientResponseBytes(response);
    if (bytes.lengthInBytes == 0) {
      throw Exception('NetworkImageSSL is an empty file: $resolved');
    }

    return await ui.instantiateImageCodec(bytes);
  }

  @override
  bool operator ==(dynamic other) {
    if (other.runtimeType != runtimeType) return false;
    final HttpsImage typedOther = other;
    return url == typedOther.url && scale == typedOther.scale;
  }

  @override
  int get hashCode => hashValues(url, scale);

  @override
  String toString() => '$runtimeType("$url", scale: $scale)';

  @override
  ImageStreamCompleter load(HttpsImage key, decode) {
    return MultiFrameImageStreamCompleter(
      codec: _loadAsync(key),
      scale: key.scale,
//        informationCollector: (StringBuffer information) {
//          information.writeln('Image provider: $this');
//          information.write('Image key: $key');
//        },
    );
  }
}

2.调用

import 'package:flutter/material.dart';

import 'https_image.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Container(
        alignment: Alignment.center,
        child: Container(
          width: 100,
          height: 100,
          decoration: BoxDecoration(
            image: const DecorationImage(
              image: HttpsImage("https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png"),
              fit: BoxFit.cover,
            ),
            borderRadius: BorderRadius.circular(8),
          ),
        ),
      ),
    );
  }
}