Why Microsoft recommended that should not use Microsoft.Web.CommandUI.dll in any SharePoint products??

Almost asp controls of SharePoint has imported the namespace "Microsoft.web.commandui.dll" to manage the Ribbon. However, this dll wasn't recommended to use if you need to customize your Ribbon. To use the type or namespace of Ribbon, we should use "Microsoft.SharePoint.WebControls". Or course, in Microsoft.SharePoint.WebControls namespace also has implemented SPRibbon, but it's not enough.

Deassembly the WebControls namespace, SPRibbon only has some types, especially it does not have TrimById method, just Microsoft.Web.CommandUI.dll has.

I don't understand why Microsoft recommended that should not use this dll!??

Do not use types or members of the Microsoft.Web.CommandUI namespace for development within a SharePoint environment, but instead use SPRibbon and related types in theMicrosoft.SharePoint.WebControls namespace. For information about customizing the ribbon in SharePoint Foundation see Server Ribbon in SharePoint Foundation.

Anybody helps me?

Passed the examination 70-573: Microsoft SharePoint 2010, Application Development

I've decided to attend the examination 70-573 because I am working as Developer of SharePoint 2010.
It's not difficult for me because I had attended the Online Course:

• Clinic 10277: What's New in Microsoft SharePoint 2010 for Developers (two hours)
• Clinic 10279: What's New in Microsoft SharePoint 2010 for IT Professionals (two hours)
  
  
  
  

and now it helps me a lot in my work, i feel better after finished learning the course and passed the examination. I will return to my blog in short day and continue sharing my knowledge about SharePoint 2007/2010.

Thanks for my co-worker helping.

Passed the examination 70-576: Designing and Developing Microsoft SharePoint 2010 Applications

I'm very happy to notice that I just passed the examination of 70-576.

A lot of skills need to be improved if you learn onlin at:

http://www.microsoft.com/learning/en/us/exam.aspx?id=70-576

Of course, that's very good document and orient the right way to pass the examination. After finish the online course you will learn the strongly knowledge to work with SharePoint 2010 with Design and Develop software based on SharePoint 2010.

Thanks again.