asp.net - c# Bundle Transform Break cache -

i create bundle transform modifies bundle content , triggers cache break, not able break cache.

so far have following code:-

public class bundleconfig {     public static void registerbundles(bundlecollection bundles)     {         stylebundle bundle = new stylebundle("~/content/global");         bundle.transforms.add(new cachebreaktransform());         bundle.include("~/css/main.css");         bundles.add(bundle);     } }  public class cachbreaktransform : ibundletransform {     void ibundletransform.process(bundlecontext context, bundleresponse response)     {         if(updateneeded())         {             response.content = getupdatedcontent(response.content);             //cache break needed here         }     } } 

i can update content of bundle, if file included in bundle hasn't changed bundle still cached , updated content not used. able break bundle cache updated content used.

two options

1. set context.httpcontext.response.cache.setrevalidation

2. setting response.cacheability nocache work, mean bundle never cached