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Layouts allow you to customize the appearance of web parts or add content. Web part layouts are custom skins that replace the HTML code and ASPX markup of the web part.
To manage the layouts of web parts, open the Web parts application and edit web parts on the Layouts tab.
Requirement
The Control declaration in the markup of the web part's user control file must contain the full relative path to the code behind file in the CodeFile attribute (CodeBehind attribute on web application installations). For example:
<%@ Control Language="C#" AutoEventWireup="true" Inherits="CMSWebParts_Navigation_cmslistmenu" CodeFile="~/CMSWebParts/Navigation/cmslistmenu.ascx.cs" %>We do not recommend calling any inline code in the web part layout file itself. Such custom code can be hard to maintain across different versions of Kentico if the code of the underlying web part changes. Only use the web part layout to extend or reorganize the web part's markup or HTML.
If you need to call custom code, create a custom web part based on the original.
Do not remove controls from the layout
Keep all of the default controls inside the code of web part layouts to ensure that web parts work correctly. If you need to hide any of the controls, add the Visible="False" attribute.
Note: Your custom web part layouts may not work after upgrading to a new version of Kentico (if the controls in the web part's markup changed). Please test your website carefully after upgrading, and update your custom layouts according to the controls in the default layout if necessary.
To select the layout for specific web part instances:
The appearance and content of the web part instance changes according to the assigned layout.
You can prepare specialized versions of web parts that use a specific layout by default:
The system automatically assigns the selected layout to new instances of the inherited web part. You can choose a different layout for existing web part instances at any time.
Web part layouts allow you to directly define any CSS classes used within the layout code.
Requirement: Enable the Allow CSS from components setting in Settings -> System -> Performance.
All pages that contain a web part with the given layout automatically load the specified styles (in addition to the website or page‑specific stylesheet).
See also: Adding CSS to page components