6.11Custom Object Content Converter (e.g. Serialization)

Created on Aug 17, 2026~4 min read

The default content converter factory of IObjectContentConverterFactory returns an ObjectContentConverter instance, which uses the ReadFromJsonAsync method of HttpResponseMessage.Content, combined with the System.Text.Json serialization library, to convert the HttpRequestMessage object into the target receiving type. However, this conversion approach may encounter deserialization failures for certain special types (such as DataTable). To address this situation, you can customize ObjectContentConverter to select or replace it with a JSON serialization tool that better suits your needs (such as Newtonsoft.Json).

When customizing, you must provide both generic and non-generic versions:

cs
// Non-generic versionpublic class CustomObjectContentConverter : ObjectContentConverter{    /// <inheritdoc />    public override async Task<object?> ReadAsync(Type resultType, HttpContentConverterContext context, CancellationToken cancellationToken = default)    {        // Get the HttpResponseMessage instance        var httpResponseMessage = context.ResponseMessage;        // Resolve the JSON serialization context information corresponding to the HttpClient client        var jsonSerializationContext =            HttpRemoteUtility.ResolveJsonSerializationContext(resultType, httpResponseMessage, ServiceProvider);        // Get the JSON deserialized value (if you need to use Newtonsoft.Json for serialization or deserialization, replace the following code with the corresponding method call from the Newtonsoft.Json library) ✅✅✅        var deserializedValue = await httpResponseMessage.Content.ReadFromJsonAsync(jsonSerializationContext.ResultType,            jsonSerializationContext.JsonSerializerOptions, cancellationToken);        // Get the converted target type value        return jsonSerializationContext.GetResultValue(deserializedValue, httpResponseMessage);    }}// Generic versionpublic class CustomObjectContentConverter<TResult> : CustomObjectContentConverter, IHttpContentConverter<TResult>{    /// <inheritdoc />    public virtual TResult? Read(HttpContentConverterContext context, CancellationToken cancellationToken = default) =>        (TResult?)base.Read(typeof(TResult), context, cancellationToken);    /// <inheritdoc />    public virtual async Task<TResult?> ReadAsync(HttpContentConverterContext context, CancellationToken cancellationToken = default) =>        (TResult?)await base.ReadAsync(typeof(TResult), context, cancellationToken);}

Next, create a custom IObjectContentConverterFactory implementation:

cs
public sealed class CustomObjectContentConverterFactory : IObjectContentConverterFactory{    /// <inheritdoc />    public IHttpContentConverter<TResult> GetConverter<TResult>(HttpContentConverterContext context)    {        // Check whether the HTTP response content type is an XML media type        if (context.ResponseMessage.IsXmlContent())        {            return new XmlObjectContentConverter<TResult>();        }        return new CustomObjectContentConverter<TResult>();    }    /// <inheritdoc />    public IHttpContentConverter GetConverter(Type resultType, HttpContentConverterContext context)    {        // Check whether the HTTP response content type is an XML media type        if (context.ResponseMessage.IsXmlContent())        {            return new XmlObjectContentConverter();        }        return new CustomObjectContentConverter();    }}

Finally, in the Startup.cs or Program.cs file, configure and register the HttpRemote service to replace the default object content converter factory functionality:

cs
services.AddHttpRemote(builder =>{    builder.UseObjectContentConverterFactory<CustomObjectContentConverterFactory>();});

In this way, through the custom ObjectContentConverter and the IObjectContentConverterFactory factory, you can ensure that the specified JSON options are used during deserialization, avoiding potential deserialization issues.