Magento - 在类别中选择显示模式“静态块和产品”时显示/隐藏CMS块

On my top level categories, I'd like to use both static blocks and products along with layered navigation. The way I want to use it is that when none of the layered navigation options have been selected, a static block only displays (toys.phtml), whereas if any of the options are selected, the static block is hidden and only the products display (toys.phtml?brand=1).

Does anyone have any suggestions for this? I'm pretty sure I can hide the products (check URL string for $_GET variables), but not sure how I can hide the static block.

Thanks in advance.

You should modify or override the Mage_Catalog_CategoryController (viewAction) and add right before the $this->renderLayout(); instruction, add the following:

if($this->getRequest()->getParam('brand'))
    $this->getLayout()->unsetBlock('yourstaticblockname');