Added IsPDF and PDFToBitmap fucntions to ImageUtils

inabox.wpf/ImageUtils.cs

@@ -24,6 +24,8 @@ using System.Linq;
 using Syncfusion.Pdf.Graphics;
 using Syncfusion.Pdf;
 using System.Diagnostics.CodeAnalysis;
+using System.Text;
+using Encoder = System.Drawing.Imaging.Encoder;
 
 namespace InABox.WPF
 {
@@ -240,21 +242,22 @@ namespace InABox.WPF
         {
             return BitmapImageFromBytes(Convert.FromBase64String(base64));
         }
-        public static BitmapImage? BitmapImageFromBytes(byte[] data)
+        public static BitmapImage? BitmapImageFromBytes(byte[]? data)
         {
+
+            if (data?.Any() != true)
+                return null;
+            
             var imageSource = new BitmapImage();
-            if(data.Length > 0)
+            using (var ms = new MemoryStream(data))
             {
-                using (var ms = new MemoryStream(data))
-                {
-                    imageSource.BeginInit();
-                    imageSource.StreamSource = ms;
-                    imageSource.CacheOption = BitmapCacheOption.OnLoad;
-                    imageSource.EndInit();
-                }
-                return imageSource;
+                imageSource.BeginInit();
+                imageSource.StreamSource = ms;
+                imageSource.CacheOption = BitmapCacheOption.OnLoad;
+                imageSource.EndInit();
             }
-            return null;
+            return imageSource;
+
         }
         
         public static BitmapImage? BitmapImageFromStream(Stream data)
@@ -830,6 +833,12 @@ namespace InABox.WPF
             }
             return null;
         }
+        
+        public static bool IsPdf(byte[] data)
+        {
+            var pdfBytes = Encoding.ASCII.GetBytes("%PDF-");
+            return data.Take(pdfBytes.Length).SequenceEqual(pdfBytes);
+        }
 
         public static byte[] GetPDFThumbnail(byte[] pdfData, int width, int height)
         {
@@ -839,6 +848,15 @@ namespace InABox.WPF
             image.Save(stream, ImageFormat.Jpeg);
             return stream.ToArray();
         }
+        
+        public static byte[] PDFToBitmap(byte[] pdfData, int page)
+        {
+            PdfLoadedDocument loadeddoc = new PdfLoadedDocument(pdfData);
+            Bitmap image = loadeddoc.ExportAsImage(page, new ImageExportSettings() { KeepAspectRatio = true });
+            MemoryStream stream = new MemoryStream();
+            image.Save(stream, ImageFormat.Jpeg);
+            return stream.ToArray();
+        }
 
         [System.Runtime.InteropServices.DllImport("gdi32.dll")]
         public static extern bool DeleteObject(IntPtr hObject);