OwinRequest extensions for getting query string, form body, and header parameters as Dictionary<string,string>

OwinRequestExtensions.cs

/// <summary>
/// Owin Request extensions.
/// </summary>
public static class OwinRequestExtensions
{
    /// <summary>
    /// Gets the combined request parameters from the form body, query string, and request headers.
    /// </summary>
    /// <param name="request">Owin request.</param>
    /// <returns>Dictionary of combined form body, query string, and request headers.</returns>
    public static Dictionary<string, string> GetRequestParameters( this IOwinRequest request )
    {
        var bodyParameters = request.GetBodyParameters();

        var queryParameters = request.GetQueryParameters();

        var headerParameters = request.GetHeaderParameters();

        bodyParameters.Merge( queryParameters );

        bodyParameters.Merge( headerParameters );

        return bodyParameters;
    }

    /// <summary>
    /// Gets the query string request parameters.
    /// </summary>
    /// <param name="request">Owin Request.</param>
    /// <returns>Dictionary of query string parameters.</returns>
    public static Dictionary<string, string> GetQueryParameters( this IOwinRequest request )
    {
        var dictionary = new Dictionary<string, string>( StringComparer.CurrentCultureIgnoreCase );

        foreach( var pair in request.Query )
        {
            var value = GetJoinedValue( pair.Value );

            dictionary.Add( pair.Key, value );
        }

        return dictionary;
    }

    /// <summary>
    /// Gets the form body request parameters.
    /// </summary>
    /// <param name="request">Owin Request.</param>
    /// <returns>Dictionary of form body parameters.</returns>
    public static Dictionary<string, string> GetBodyParameters( this IOwinRequest request )
    {
        var dictionary = new Dictionary<string, string>( StringComparer.CurrentCultureIgnoreCase );

        var formCollectionTask = request.ReadFormAsync();

        formCollectionTask.Wait();

        foreach( var pair in formCollectionTask.Result )
        {
            var value = GetJoinedValue( pair.Value );

            dictionary.Add( pair.Key, value );
        }

        return dictionary;
    }

    /// <summary>
    /// Gets the header request parameters.
    /// </summary>
    /// <param name="request">Owin Request.</param>
    /// <returns>Dictionary of header parameters.</returns>
    public static Dictionary<string, string> GetHeaderParameters( this IOwinRequest request )
    {
        var dictionary = new Dictionary<string, string>( StringComparer.CurrentCultureIgnoreCase );

        foreach( var pair in request.Headers )
        {
            var value = GetJoinedValue( pair.Value );

            dictionary.Add( pair.Key, value );
        }

        return dictionary;
    }

    private static string GetJoinedValue( string[] value )
    {
        if( value != null )
            return string.Join( ",", value );

        return null;
    }
}

Your Dictionary<TKey, TValue> Merge extension is missing - does this override values in the request body with those in the query string or headers if there are duplicate keys?

Yeah, ditto what @RJCuthbertson said... No "Merge" in this code

Add this to your code to get Merge functionality
///

/// Merges the current data to a new data
///

///
public static void Merge<TKey, TValue>(this IDictionary<TKey, TValue> to, IDictionary<TKey, TValue> data)
{
foreach (var item in data)
{
if (to.ContainsKey(item.Key) == false)
{
to.Add(item.Key, item.Value);
}
}
}