The Page placeholder web part allows you to specify a part of the page where the content of sub-pages should be displayed. It is possible to place multiple page placeholder web parts on a single page template.
If you wish to use multiple placeholder web parts on a single page template, you can use the CMSContent
control in the layout code of child page templates to indicate inside which placeholder content should be displayed.
For example, a child document could use the following syntax in its page layout:
<cms:CMSContent runat="server" id="cntLeft" PagePlaceholderID="plcLeft">
<cc1:CMSWebPartZone ID="zoneLeft" runat="server" />
<cc1:CMSWebPartZone ID="zoneCenter" runat="server" />
<cms:CMSContent runat="server" ID="cntRight" PagePlaceholderID="plcRight">
<cc1:CMSWebPartZone ID="zoneRight" runat="server" />
In this scenario, the content of the zoneLeft web part zone would be displayed within the page placeholder with a Web part control ID set to plcLeft, while the zoneRight zone would only be visible within the plcRight placeholder.
Please note that if a document has a parent with multiple page placeholders, content that is not wrapped in a CMSContent control (i.e. the zoneCenter zone) will be displayed in the placeholder web part that is processed first (this is nondeterministic).
Help URL: http://devnet.kentico.com/docs/webparts/index.html?pageplaceholder_overview.htm