feat:增加朋友圈评论显示模块

lib/utils/screenshot_util.dart

@@ -9,22 +9,85 @@ import 'package:share_plus/share_plus.dart';
 
 /// 截图工具类
 class ScreenshotUtil {
+  static double pixelRatio = 3.0;
+  static Duration delay = const Duration(milliseconds: 50);
+  static String watermarkText = '来自 食光集';
+
   // 截图功能
-  static Future<Uint8List?> captureRecipeImage({
-    required GlobalKey globalKey,
-    double pixelRatio = 3.0,
-    Duration delay = const Duration(milliseconds: 50),
-  }) async {
+  static Future<Uint8List?> captureImage({required GlobalKey globalKey}) 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(
+
+    // 添加水印
+    return await _addWatermarkToImage(image);
+  }
+
+  // 添加水印到图片
+  static Future<Uint8List> _addWatermarkToImage(ui.Image image) async {
+    // 创建画布
+    final recorder = ui.PictureRecorder();
+    final canvas = Canvas(recorder);
+
+    // 绘制原始图片
+    canvas.drawImage(image, Offset.zero, Paint());
+
+    // 添加文字水印
+    _drawTextWatermark(canvas, image);
+
+    // 生成最终图片
+    final picture = recorder.endRecording();
+    final watermarkedImage = await picture.toImage(image.width, image.height);
+    final ByteData? byteData = await watermarkedImage.toByteData(
       format: ui.ImageByteFormat.png,
     );
 
-    return byteData?.buffer.asUint8List();
+    return byteData!.buffer.asUint8List();
+  }
+
+  // 绘制文字水印
+  static void _drawTextWatermark(Canvas canvas, ui.Image image) {
+    final textPainter = TextPainter(
+      text: TextSpan(
+        text: watermarkText,
+        style: TextStyle(
+          color: Color(0x99FFFFFF),
+          fontSize: 28,
+          fontFamily: 'CustomFont',
+          fontWeight: FontWeight.w600,
+        ),
+      ),
+      textDirection: TextDirection.ltr,
+    );
+
+    textPainter.layout(maxWidth: image.width.toDouble());
+
+    // 计算水印位置（右下角，带边距）
+    final double x = image.width - textPainter.width - 40;
+    final double y = image.height - textPainter.height - 40;
+
+    // 绘制文字背景
+    final backgroundPaint =
+        Paint()
+          ..color = const ui.Color(0x4D000000)
+          ..style = PaintingStyle.fill;
+
+    // 绘制圆角矩形背景
+    final backgroundRect = RRect.fromRectAndRadius(
+      Rect.fromLTWH(
+        x - 12,
+        y - 6,
+        textPainter.width + 24,
+        textPainter.height + 12,
+      ),
+      Radius.circular(6),
+    );
+    canvas.drawRRect(backgroundRect, backgroundPaint);
+
+    // 绘制文字
+    textPainter.paint(canvas, Offset(x, y));
   }
 
   // 保存图片到临时文件
@@ -41,7 +104,7 @@ class ScreenshotUtil {
     required String shareText,
   }) async {
     try {
-      final imageBytes = await captureRecipeImage(globalKey: globalKey);
+      final imageBytes = await captureImage(globalKey: globalKey);
 
       if (imageBytes != null) {
         final imageFile = await saveImageToFile(imageBytes, fileName);