Your Web Forms Mobile Application can optionally select the correct theme dynamically at runtime, so one single ePortal presentation application can be used to provide a web application which closely emulates a native app on each different platform.

When an end-user connects to a page in your web application, the web browser sends a text field in an HTTP request header that contains the name and version of the browser. This string is the user agent string.

The ePortal presentation project also contains the file ThemeSelection.xml under the folder App_Data. This file is used at runtime to select the correct theme, based on the user agent string. If necessary, you can edit this file to change which theme is selected at runtime. For more details on ThemeSelection.xml, see the comments in the file.

To enable runtime theme selection, you must set the property useUserAgentString to true in the AppSettings section of the web.config file as follows:

<AppSettings>         <add key="useUserAgentString" value="true"/> </AppSettings>

If you set useUserAgentString to false, then runtime theme selection is disabled. In this case, the designer theme will also be used at runtime. Refer to Designer Theme Selection for more information on selecting themes.

When creating a new smartphone or tablet project, the useUserAgentString property is set to true. You can set the useUserAgentString property in either of the following ways:

Unisys.ePortal.Mobile.MobilePage Class

Runtime theme selection is implemented by the class Unisys.ePortal.Mobile.MobilePage. Therefore, each .aspx web page must extend the class Unisys.ePortal.Mobile.MobilePage in order for runtime theme selection to work properly.

If the user attempts to access an .aspx page at runtime with runtime theme selection enabled, and the code behind file (.aspx.cs) for that page does not extend Unisys.ePortal.Mobile.MobilePage, then the page will fail to load.  The browser window shows the following message:

Exception: The page "pagename" does not inherit from Unisys.ePortal.Mobile.MobilePage. Edit the class declaration, in the file "pagename.aspx.cs", as shown below.

      public partial class : Unisys.ePortal.Mobile.MobilePage

Update the .aspx.cs file as indicated in the message to fix the problem.