更新 HEICFile 类以支持新特性，添加图像尺寸获取功能，重构解析逻辑，增强代码可读性和健壮性

main.py

@@ -1,22 +1,28 @@
-# In main.py
+# pyheic_struct/main.py
+
 from heic_file import HEICFile
 
 def analyze_file(filename: str):
     print(f"--- Analyzing {filename} ---")
     heic_file = HEICFile(filename)
-    
+
     # List all available items in the file
     heic_file.list_items()
-    
+
     # Get the ID of the primary image
     primary_id = heic_file.get_primary_item_id()
     if primary_id:
-        print(f"\nThe primary item ID is: {primary_id}")
+        print(f"The primary item ID is: {primary_id}")
+
+        # --- Use our new feature! ---
+        size = heic_file.get_image_size(primary_id)
+        if size:
+            print(f"Primary image dimensions (WxH): {size[0]} x {size[1]}")
     
     print("\n" + "="*40 + "\n")
 
 def main():
-    analyze_file('apple.heic')
+    analyze_file('apple.HEIC')
     analyze_file('samsung.heic')
 
 if __name__ == "__main__":