feat:增加分享图片功能

lib/utils/screenshot_util.dart

@@ -0,0 +1,61 @@
+import 'dart:io';
+import 'dart:typed_data';
+import 'dart:ui' as ui;
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:food_hub_app/widgets/common/index.dart';
+import 'package:path_provider/path_provider.dart';
+import 'package:share_plus/share_plus.dart';
+
+/// 截图工具类
+class ScreenshotUtil {
+  // 截图功能
+  static Future<Uint8List?> captureRecipeImage({
+    required GlobalKey globalKey,
+    double pixelRatio = 3.0,
+    Duration delay = const Duration(milliseconds: 50),
+  }) async {
+    // 等待一帧确保UI已渲染
+    await Future.delayed(delay);
+    final RenderObject? render = globalKey.currentContext!.findRenderObject();
+    final RenderRepaintBoundary boundary = render as RenderRepaintBoundary;
+    final ui.Image image = await boundary.toImage(pixelRatio: pixelRatio);
+    final ByteData? byteData = await image.toByteData(
+      format: ui.ImageByteFormat.png,
+    );
+
+    return byteData?.buffer.asUint8List();
+  }
+
+  // 保存图片到临时文件
+  static Future<File> saveImageToFile(Uint8List bytes, String fileName) async {
+    final directory = await getTemporaryDirectory();
+    final File imageFile = File('${directory.path}/$fileName');
+    await imageFile.writeAsBytes(bytes);
+    return imageFile;
+  }
+
+  static Future<void> captureAndShare({
+    required GlobalKey globalKey,
+    required String fileName,
+    required String shareText,
+  }) async {
+    try {
+      final imageBytes = await captureRecipeImage(globalKey: globalKey);
+
+      if (imageBytes != null) {
+        final imageFile = await saveImageToFile(imageBytes, fileName);
+        await SharePlus.instance.share(
+          ShareParams(files: [XFile(imageFile.path)], text: shareText),
+        );
+
+        // 分享后删除临时文件
+        await imageFile.delete();
+      } else {
+        showErrorToast('生成图片失败，请重试');
+      }
+    } catch (e) {
+      showErrorToast('分享失败: $e');
+    }
+  }
+}