# Codec_FSharpMapSurrogate<TKey, TValue>.ReadValue(Reader<TReaderInput>, Field)

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.serialization.fsharp/orleanscodegen.orleans.serialization.codec-fsharpmapsurrogate-2/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.serialization.fsharp/orleanscodegen.orleans.serialization.codec-fsharpmapsurrogate-2/methods/)

```csharp
public FSharpMapSurrogate<TKey, TValue> Codec_FSharpMapSurrogate<TKey, ReadValue<TReaderInput>(ref Reader<TReaderInput> reader, Field field)
```

Reads a value.

### Parameters

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

### Returns

The value.