combit List & Label 25 - .NET Online Web Help
combit.ListLabel25.Web Assembly

List & Label can also be used within web applications, albeit with a number of limitations. For ASP.NET-based web applications, List & Label contains components for displaying reports in the web browser (Html5ViewerControl), which also support complex features such as drill-down, as well as an independent version of the Designer with which reports can be designed on the server with the familiar List & Label Designer (Web Designer).


Printing within a web application is basically the same as an export e.g. to PDF format, where all dialogs are suppressed. How this is done in general is described in section "Export Without User Interaction". After the report is generated that way, the browser of the user can be directed to the created file by the usual mechanisms. Alternatively the file can be sent directly to the user via e-mail if the creation is to be scheduled (see also class MailJob).

A printer driver has to be installed on the server as well so the print can be successfully executed. List & Label works closely together with the Windows-GDI and therefore requires a printer device context for all operations. The Microsoft XPS printer driver (automatically installed on all systems from .NET Framework 3.5 and higher) is also suitable as a reference printer.

As the process/service is executed in the context of the IIS, it is important that the used ApplicationPool is configured accordingly to have access to the installed printer driver. From IIS versions 7.0/7.5 on (from Windows 7/Server 2008 R2 on), however, the standard identity is the 'ApplicationPoolIdentity'. This is a so called virtual account, that might not have access to the system resources like the printer driver. Therefore, it is mandatory that the defined identity must be reconfigured to e.g. 'NetworkService'.

Generally the project files are created within a client application and then published together with the web application. The following image visualizes the principle:



Contains components to use the web designer without local List & Label client installation to design project files on the server.