title: Field Configuration sidebar_position: 5 id: field_configuration license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

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This page covers field-level serializer configuration for C# generated serializers.

[ForyObject] and [Field]

Use [ForyObject] to enable source-generated serializers. Use [Field] to override integer encoding for a specific field.

using Apache.Fory;

[ForyObject]
public sealed class Metrics
{
    // Fixed-width 32-bit encoding
    [Field(Encoding = FieldEncoding.Fixed)]
    public uint Count { get; set; }

    // Tagged 64-bit encoding
    [Field(Encoding = FieldEncoding.Tagged)]
    public ulong TraceId { get; set; }

    // Default (varint) encoding
    public long LatencyMicros { get; set; }
}

Available Encodings

EncodingMeaning
FieldEncoding.VarintVariable-length integer encoding (default)
FieldEncoding.FixedFixed-width integer encoding
FieldEncoding.TaggedTagged integer encoding (long / ulong only)

Supported Field Types for Encoding Override

[Field(Encoding = ...)] currently applies to:

  • int
  • uint
  • long
  • ulong

Nullable value variants (for example long?) are also handled by generated serializers.

Nullability and Reference Tracking

  • Field nullability comes from C# type nullability (string?, nullable value types, etc.).
  • Reference tracking is controlled at runtime by ForyBuilder.TrackRef(...).

Related Topics