/// <summary>
/// 合并并添加样式名称。
/// </summary>
/// <param name="output">表情输出实例对象。</param>
/// <param name="context">当前标签上下文实例对象。</param>
/// <param name="classNames">需要添加合并的样式名称。</param>
public static void MergeClassNames(this TagHelperOutput output, TagHelperContext context,
params string[] classNames)
{
if (classNames == null)
{
return;
}
var htmlClassNames = context.GetClassNames();
htmlClassNames.AddRange(classNames);
output.Attributes.SetAttribute("class", string.Join(" ", htmlClassNames.Distinct()));
}