How do I programmatically create a full-width Adaptive Card?

So to do that in C# you need to pass a dictionary value in Adaptive card AdditionalProperties.

Here's the code snippet-

        var additionalProperty = new SerializableDictionary<string, object>();
        additionalProperty.Add("msteams", new
        {
            width = "Full",
        });
        var adaptiveCard = new AdaptiveCard(new AdaptiveSchemaVersion(1, 3))
        {
            Body = new System.Collections.Generic.List<AdaptiveElement>
            {
                new AdaptiveTextBlock
                {
                    Text = "Some Text",
                }
            },
            AdditionalProperties = additionalProperty
        };

This should work.!