Added ImageUtils.TryGetImageFormat to query without exception

inabox.wpf/ImageUtils.cs

@@ -23,6 +23,7 @@ using System;
 using System.Linq;
 using Syncfusion.Pdf.Graphics;
 using Syncfusion.Pdf;
+using System.Diagnostics.CodeAnalysis;
 
 namespace InABox.WPF
 {
@@ -613,6 +614,36 @@ namespace InABox.WPF
             return System.Windows.Media.Color.FromArgb(color.A, (byte)red, (byte)green, (byte)blue);
         }
 
+        public static bool TryGetImageType(byte[] imageData, [NotNullWhen(true)] out ImageFormat? format)
+        {
+            foreach (var signatureEntry in SignatureTable)
+                foreach (var signature in signatureEntry.Value)
+                {
+                    var isMatch = true;
+                    for (var i = 0; i < signature.Length; i++)
+                    {
+                        var signatureByte = signature[i];
+
+                        // ToString("X") gets the hex representation and pads it to always be length 2
+                        var imageByte = imageData[i]
+                            .ToString("X2");
+
+                        if (signatureByte == imageByte)
+                            continue;
+                        isMatch = false;
+                        break;
+                    }
+
+                    if (isMatch)
+                    {
+                        format = signatureEntry.Key;
+                        return true;
+                    }
+                }
+            format = null;
+            return false;
+        }
+
         /// <summary>
         ///     Takes a byte array and determines the image file type by
         ///     comparing the first few bytes of the file to a list of known
@@ -623,27 +654,10 @@ namespace InABox.WPF
         /// <exception cref="ArgumentException">Thrown if the image type can't be determined</exception>
         public static ImageFormat GetImageType(byte[] imageData)
         {
-            foreach (var signatureEntry in SignatureTable)
-            foreach (var signature in signatureEntry.Value)
+            if(TryGetImageType(imageData, out var format))
             {
-                var isMatch = true;
-                for (var i = 0; i < signature.Length; i++)
-                {
-                    var signatureByte = signature[i];
-
-                    // ToString("X") gets the hex representation and pads it to always be length 2
-                    var imageByte = imageData[i]
-                        .ToString("X2");
-
-                    if (signatureByte == imageByte)
-                        continue;
-                    isMatch = false;
-                    break;
-                }
-
-                if (isMatch) return signatureEntry.Key;
+                return format;
             }
-
             throw new ArgumentException("The byte array did not match any known image file signatures.");
         }