Sharepoint Webart ProviderConnectionPoint is null always

Question

I want to create custom web part that adds another provider and consumer web part. But i always get ProviderConnectionPoint as null.

Can anyone please tell me how to write web part that can add other web parts in the page and also connect them.

System.Web.UI.WebControls.WebParts.ProviderConnectionPointCollection providerConnections = webPartManager.GetProviderConnectionPoints(webPartManager.WebParts[0]);

The above code also return ProviderConnectionPointCollection as null

Any help is appreciated. Thanks in Advance