Printing in VB.NET

Create QR Code 2d barcode in VB.NET Printing

than assign the items panel to the PageVisual, I assign the entire grid, header, items, footer, and all I. Figure 19.9 shows the header and footer at the page break between page 1 and page 2. It s relatively easy to get the page number, as you see in the example code. It s more difficult to get a total page count. One common request for reports is the ability to show the page number as Page x of y where x is the current page and y is the total count of pages. Should you desire to do this, you ll need to precalculate the pages prior to printing the approach I took in the version posted to CodePlex. Supporting multipage printing with headers and footers is easily done, given the flexibility of data templates and the no assumptions low-level nature of the Silverlight printing API. Though the performance of the printing system isn t quite up to par for huge multipage reports, the API does nothing to prevent you from creating those types of print jobs should they be appropriate to your project. Combining the print API with binding and templates offers a good reuse story, and allows you to spend more time in XAML using design tools and less time in code. You could even extend the template model to include a report footer for totals, or modify it further to support nested groups. The sky s the limit.

19.4 Summary

In order for Silverlight to be taken seriously in the business world, it had to support a flexible printing API. Though you can sometimes punt and skip on printing support in consumer applications, the business world is less forgiving. With Silverlight 4, the product team delivered a very flexible printing API. It may still be rough around the edges, especially in performance and, in some cases, raster quality of the output, but it s still a 1.0 API, and quite usable at that. The printing API in Silverlight can be used for anything from printing simple onscreen content to complex multipage reports with headers, footers, grouping, and

Summary

more. In this chapter we saw how to print content as it appears onscreen, then looked at a few ways to handle scaling that content so it better fit the printer. We also looked at content that was purpose-built specifically for the printer, whether a simple singlepage list or a multipage report including headers and footers. The information in this chapter can serve as a foundation upon which you can build your own printing and reporting systems in your applications. But, should you want to take the knowledge and simply apply it to someone else s code, David Poll and I have created a simple report writer project on CodePlex at http://silverlightreporting. codeplex.com. We plan to use that as a test bed for new ideas and provide something real that you can build upon to meet your own requirements. Take a look at it, if only to see some of the other techniques described in this chapter, such as precalculating pages. In the next chapter, we ll look at the media capabilities of Silverlight, including the exciting webcam and microphone APIs introduced in Silverlight 4, and the media APIs introduced in Silverlight 3.

Interactive playback Playlist management Working with raw media Working with the webcam and microphone

If you ask most non-Silverlight developers what Silverlight is, 8 out of 10 will probably say it s Microsoft s web media player. Part of that reputation comes from Silverlight 1.0, which was only good as a media player. The other part comes from the incredible advances the Silverlight team has made in making Silverlight a first class media platform for the web. Silverlight excels at delivering high-quality HD media. In fact, it was one of the first web technologies to support true 720p and 1080p HD media over decent but not abnormal network pipes. Silverlight has been the driving media force behind Netflix, as well as many online events such as the Olympics and March Madness. Media is what has helped Silverlight expand onto the majority of internetconnected desktops.