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lib/utils/transfer/download.dart

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+//下载文件
+import 'dart:io';
+
+import 'package:path_provider/path_provider.dart';
+
+class LocalDownload {
+  static Future<String> getLocalFilePath(String url, String path) async {
+    Uri uri = Uri.parse(url);
+    String fileName = uri.pathSegments.last;
+    //获取下载目录
+    Directory dir = await getApplicationCacheDirectory();
+    Directory uploadPath = Directory("${dir.path}$path/");
+    return uploadPath.path + fileName;
+  }
+
+  /// 公用下载方法
+  /// url 下载网络地址
+  /// path 存储地址，如/test
+  /// onProgress 下载回调函数
+  /// onDone 下载完毕回调
+  static downLoadFile({
+    required url,
+    required path,
+    required Function(double) onProgress,
+    required Function(String) onDone,
+  }) async {
+    HttpClient client = HttpClient();
+    Uri uri = Uri.parse(url);
+    //获取本地文件路径
+    String filePath = await getLocalFilePath(url, path);
+    // 发起 get 请求
+    HttpClientRequest request = await client.getUrl(uri);
+    // 响应
+    HttpClientResponse response = await request.close();
+    int contentLength = response.contentLength; // 获取文件总大小
+    int bytesReceived = 0; // 已接收的字节数
+    List<int> chunkList = [];
+    if (response.statusCode == 200) {
+      response.listen(
+        (List<int> chunk) {
+          chunkList.addAll(chunk);
+          bytesReceived += chunk.length; //更新已接受的字节数
+          //进度
+          double progress = bytesReceived * 100 / contentLength * 100;
+          progress = (progress / 100).truncateToDouble();
+          onProgress(progress);
+        },
+        onDone: () async {
+          //下载完毕
+          client.close();
+          File file = File(filePath);
+          if (!file.existsSync()) {
+            file.createSync(recursive: true);
+            await file.writeAsBytes(chunkList);
+          }
+          onDone(file.path);
+        },
+        onError: () {
+          client.close();
+        },
+        cancelOnError: true,
+      );
+    }
+  }
+
+  ///获取本地地址
+  ///
+  static Future<String> getFilePath({
+    required url,
+    required path,
+  }) async {
+    //获取本地文件路径
+    String filePath = await getLocalFilePath(url, path);
+    File file = File(filePath);
+    if (file.existsSync()) {
+      return file.path;
+    } else {
+      return '';
+    }
+  }
+}