Handle long file paths in UriFromFilePath (#19955)

* fix long path

* Update UriExtensionsTests.cs

* Update StorageProviderHelpers.cs

src/Avalonia.Base/Platform/Storage/FileIO/StorageProviderHelpers.cs

@@ -37,11 +37,19 @@ internal static class StorageProviderHelpers
 
     public static Uri UriFromFilePath(string path, bool isDirectory)
     {
-        var uriPath = new StringBuilder(path)
-            .Replace("%", $"%{(int)'%':X2}")
-            .Replace("[", $"%{(int)'[':X2}")
-            .Replace("]", $"%{(int)']':X2}");
-
+        var uriPath = new StringBuilder();
+        bool isLongPath = path.StartsWith(@"\\?\", StringComparison.Ordinal);//Windows long path prefix
+        if (isLongPath)
+        {
+            uriPath.Append(path, 4, path.Length - 4);
+        }
+        else
+        {
+            uriPath.Append(path);
+        }
+        uriPath = uriPath.Replace("%", $"%{(int)'%':X2}")
+                                    .Replace("[", $"%{(int)'[':X2}")
+                                    .Replace("]", $"%{(int)']':X2}");
         if (!path.EndsWith('/') && isDirectory)
         {
             uriPath.Append('/');

tests/Avalonia.Base.UnitTests/Utilities/UriExtensionsTests.cs

@@ -40,4 +40,15 @@ public class UriExtensionsTests
 
         Assert.Equal(path, uri.LocalPath);
     }
+
+    [Theory]
+   
+    [InlineData(@"\\?\D:\abcdefgh\abcdefgh\abcdefabcdefgh\abcdefghabcdefghabcdefgha\bcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefgh\abcdefghabcdefghabcdefgha\bcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefgh",
+        @"D:\abcdefgh\abcdefgh\abcdefabcdefgh\abcdefghabcdefghabcdefgha\bcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefgh\abcdefghabcdefghabcdefgha\bcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefghabcdefgh")]
+    public void Should_Convert_Long_File_Path_To_Uri_And_Back(string prepath,string path)
+    {
+        var uri = StorageProviderHelpers.UriFromFilePath(prepath, false);
+
+        Assert.Equal(path, uri.LocalPath);
+    }
 }