Скачать или смотреть C# WPF DataGrid Printing - The Big Secret

C# WPF DataGrid Printing - The Big Secret
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Perhaps “The Big Secret” is slightly click bait, but calling it “My Solution” may not have caught your eye.

At first, I just wanted to print a DataGrid page by page. I was pleased to find a DataGrid (like any Visual class object) can print itself by using the PrintDialog.PrintVisual method. But what if the DataGrid is bigger than the page?

Then I looked at the DocumentPaginator, FlowDocument and the FixedDocument classes.
The DocumentPaginator appeared to be for when you have already solved how to paginate your printing, which was the core problem to be solved.
The FlowDocument was bit too “flowy” in that content flowed and was resized, which is after all, as it was intended to do.
The FixedDocument was said to be a WYSIWYG, which was better for fixed layouts. But I was a bit wary, because the printing examples I found showed I had to position each element on the page, they did not “flow” as they did in the FlowDocument.

For printing DataGrids the solutions offered, were to recreate the DataGrid by creating and drawing tables on the page, based on the items from data/item source collection. And to calculate pagination base on a number of items that may fit per page.

This raised a few issues:
My nice DataGrid layout would need to be recreated using some table and column header methods.
If I was using DataGrid grouping, it would be difficult to calculate the items per page, depending on the group header space needed. DataGrids could already print themselves, I just needed to paginate them.

Also, what about page headers and footers, and how to display the simple “Page # of pages”, when you don’t know how many pages are in the document at the time the current page is being created. I guessed you would have to go back and page-through the document updating the pages count. That sounded like going back through a collection of objects with an update to some property with data binding, as we may do on a normal screen window.

Then I thought, what if we recreated the DataGrid control using some of the items from its data/item source collection, and by adjusting the number of items used, grew or sized the DataGrid until it fit to a given height which would become the content area of a page. Then for the following pages, we create another new DataGrid based of the remaining items in the collection.