public CrossDomainPoliciesMiddleware(RequestDelegate next, CrossDomainPoliciesOptions option)
        {
            this.next = next;

            switch (option)
            {
            case CrossDomainPoliciesOptions.None:
                headerValue = "none";
                break;

            case CrossDomainPoliciesOptions.MasterOnly:
                headerValue = "master-only";
                break;

            case CrossDomainPoliciesOptions.ByContentType:
                headerValue = "by-content-type";
                break;

            case CrossDomainPoliciesOptions.ByFtpFilename:
                headerValue = "by-ftp-filename";
                break;

            case CrossDomainPoliciesOptions.All:
                headerValue = "all";
                break;
            }
        }
 /// <summary>
 /// Adds middleware that adds the X-Permitted-Cross-Domain-Policies header.
 /// </summary>
 /// <param name="app">The <see cref="IApplicationBuilder"/> instance this method extends.</param>
 /// <param name="option">A <see cref="CrossDomainPoliciesOptions"/> value representing an option to be set.</param>
 public static IApplicationBuilder UseCrossDomainPolicies(this IApplicationBuilder app, CrossDomainPoliciesOptions option)
 {
     return(app.UseMiddleware <CrossDomainPoliciesMiddleware>(option));
 }