# Codec_BackwardCompatible Methods

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleanscodegen.orleans.versions.compatibility.codec-backwardcompatible/)

## Deserialize(Reader<TReaderInput>, BackwardCompatible) {#deserialize-1-ref-orleans-serialization-buffers-reader-treaderinput-orleans-vers-2ce4e497}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleanscodegen.orleans.versions.compatibility.codec-backwardcompatible/methods/deserialize-1-ref-orleans-serialization-buffers-reader-treaderinput-orleans-vers-2ce4e497/)

```csharp
public void Deserialize<TReaderInput>(ref Reader<TReaderInput> reader, BackwardCompatible instance)
```

### Parameters

- `reader` (`Reader<TReaderInput>`)
- `instance` (`BackwardCompatible`)

## ReadValue(Reader&lt;TReaderInput&gt;, Field) {#readvalue-1-ref-orleans-serialization-buffers-reader-treaderinput-orleans-serial-df05e990}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleanscodegen.orleans.versions.compatibility.codec-backwardcompatible/methods/readvalue-1-ref-orleans-serialization-buffers-reader-treaderinput-orleans-serial-df05e990/)

```csharp
public BackwardCompatible ReadValue<TReaderInput>(ref Reader<TReaderInput> reader, Field field)
```

Reads a value.

### Parameters

- `reader` (`Reader<TReaderInput>`): The reader.
- `field` (`Field`): The field.

### Returns

The value.

## Serialize(Writer&lt;TBufferWriter&gt;, BackwardCompatible) {#serialize-1-ref-orleans-serialization-buffers-writer-tbufferwriter-orleans-versi-0d13ba78}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleanscodegen.orleans.versions.compatibility.codec-backwardcompatible/methods/serialize-1-ref-orleans-serialization-buffers-writer-tbufferwriter-orleans-versi-0d13ba78/)

```csharp
public void Serialize<TBufferWriter>(ref Writer<TBufferWriter> writer, BackwardCompatible instance)
```

### Parameters

- `writer` (`Writer<TBufferWriter>`)
- `instance` (`BackwardCompatible`)

## WriteField(Writer&lt;TBufferWriter&gt;, uint, Type, BackwardCompatible) {#writefield-1-ref-orleans-serialization-buffers-writer-tbufferwriter-uint-system-9a9c3dca}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleanscodegen.orleans.versions.compatibility.codec-backwardcompatible/methods/writefield-1-ref-orleans-serialization-buffers-writer-tbufferwriter-uint-system-9a9c3dca/)

```csharp
public void WriteField<TBufferWriter>(ref Writer<TBufferWriter> writer, uint fieldIdDelta, Type expectedType, BackwardCompatible value)
```

Writes a field.

### Parameters

- `writer` (`Writer<TBufferWriter>`): The writer.
- `fieldIdDelta` (`uint`): The field identifier delta.
- `expectedType` (`Type`): The expected type.
- `value` (`BackwardCompatible`): The value.