flutter 网络地址URL转file

方法1

import 'dart:io';
import 'package:http/http.dart' as http;
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';

Future<File> _fileFromImageUrl() async {
    final response = await http.get(Uri.parse('https://example.com/xyz.jpg)');

    final documentDirectory = await getApplicationDocumentsDirectory();

    final file = File(join(documentDirectory.path, 'imagetest.png'));

    file.writeAsBytesSync(response.bodyBytes);

    return file;
  }

方法2

import 'dart:io';   
import 'package:dio/dio.dart';
import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';


Future<File> getImage({required String url}) async {
  /// Get Image from server
  final Response res = await Dio().get<List<int>>(
    url,
    options: Options(
        responseType: ResponseType.bytes,
      ),
    );

    /// Get App local storage
    final Directory appDir = await getApplicationDocumentsDirectory();

    /// Generate Image Name
    final String imageName = url.split('/').last;

    /// Create Empty File in app dir & fill with new image
    final File file = File(join(appDir.path, imageName));

    file.writeAsBytesSync(res.data as List<int>);

    return file;
}

方法3

Future<File> fileFromImageUrl() async {
String img='https://pps.whatsapp.net/v/t61.24694-24/160266256_1115367465775510_3546030680878251116_n.jpg?ccb=11-4&oh=01_AdSsrMGOPfs8CUJsEkYImMUu5L4DAzt2ym8eBrdsMG5O0Q&oe=63D7B45E';
    final response = await http.get(Uri.parse(img));

    final documentDirectory = await getApplicationDocumentsDirectory();

    final file =
        File(p.join(documentDirectory.path, 'File Name.jpg'));

    file.writeAsBytesSync(response.bodyBytes);

    return file;
  }