select OutputFormatter depending on the query parameter-CodePudding

I need to select OutputFormatter depending on the query parameter. How to do that? I am moving from .NET Framework WebApi to .NET Core WebApi. The .NET Framework WebApi had DefaultContentNegotiator class do that:

public class CustomContentNegotiator : DefaultContentNegotiator
{
        
    
    public override ContentNegotiationResult Negotiate(Type type, HttpRequestMessage request, IEnumerable<MediaTypeFormatter> formatters)
        {       
                //Read query from request object and add output formatters below
                bindFormatters = new List<MediaTypeFormatter>
                {
                    new ConvertResultRawFormatter(),
                    new JsonMediaTypeFormatter
                    {
                        SerializerSettings =
                        {
                            NullValueHandling = NullValueHandling.Ignore
                        }
                    }
                };
            }
    
            return base.Negotiate(type, request, bindFormatters);
        }
}

replace in configuration with new formatted negotiator

 config.Services.Replace(typeof(IContentNegotiator), new CustomContentNegotiator());

CodePudding user response：

Will the custom output formatters not work for you? Read this ms docs

CodePudding user response：

From the comments it seems that the real question is how to add the Content-Disposition: inline header if the URL contains download=inline parameter. This doesn't concern formatting or content negotiation.

There are several ways to add headers to a response. One of them is to add inline middleware that adds the header if the query parameter is present :

app.Use(async (context, next) => 
{
    context.Response.OnStarting(() => 
    {
        var download= context.Request.Query["download"];
        if (download=="inline")
        {
            context.Response.Headers.Add("Content-Disposition", "inline");
        }
    }
}

This affects all routes