Add files via upload

tools/viewer/ImageFileHandler.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Drawing;
+using System.IO;
+
+namespace KortAppZ.Tools.Viewer
+{
+    public static class ImageFileHandler
+    {
+        private static readonly string[] SupportedExtensions = 
+        {
+            ".jpg", ".jpeg", ".png", ".bmp", ".gif", ".tiff", ".tif"
+        };
+        
+        public static bool IsImageFile(string filePath)
+        {
+            if (string.IsNullOrEmpty(filePath))
+                return false;
+                
+            string extension = Path.GetExtension(filePath).ToLower();
+            return Array.Exists(SupportedExtensions, ext => ext == extension);
+        }
+        
+        public static Image LoadImage(string filePath)
+        {
+            if (!IsImageFile(filePath))
+                throw new ArgumentException("不支持的图片格式");
+                
+            if (!File.Exists(filePath))
+                throw new FileNotFoundException("图片文件不存在", filePath);
+                
+            try
+            {
+                return Image.FromFile(filePath);
+            }
+            catch (Exception ex)
+            {
+                throw new Exception($"无法加载图片: {ex.Message}", ex);
+            }
+        }
+    }
+}