WPF打印/ xps问题

Question

I have written the following chunk of code that prints my ListBox perfectly when being sent to a physical printer, however when trying to send it to the XPS printer driver or using the XpsDocumentWriter class (I assume they use the same code under the hood) I receive the following exception:

System.ArgumentException was unhandled by user code Message=Width and Height must be non-negative. Source=ReachFramework StackTrace: at System.Windows.Xps.Serialization.VisualSerializer.WriteTileBrush(String element, TileBrush brush, Rect bounds)

The exception obviously points to an item not having a correct width/height however I have debugged the code when sending it to the different printers (physical and XPS driver) and I haven't been able to find any differences.

Below is how I create the visual to send to the printer:

private ScrollViewer GeneratePrintableView()
    {
        ScrollViewer scrollView = new ScrollViewer();

        Grid grid = new Grid { Background = Brushes.White, Width = this.myListBox.ActualWidth, Height = this.myListBox.ActualHeight };

        grid.RowDefinitions.Add(new RowDefinition());
        grid.RowDefinitions[0].Height = new GridLength(0, GridUnitType.Auto);
        grid.RowDefinitions.Add(new RowDefinition());
        grid.RowDefinitions[1].Height = new GridLength(0, GridUnitType.Auto);

        // Add the title and icon to the top
        VisualBrush titleClone = new VisualBrush(this.TitleBar);
        var titleRectangle = new Rectangle { Fill = titleClone, Width = this.TitleBar.ActualWidth, Height = this.TitleBar.ActualHeight };
        grid.Children.Add(titleRectangle);
        Grid.SetRow(titleRectangle, 0);

        this.myListBox.Width = this.myListBox.ActualWidth;
        this.myListBox.Height = this.myListBox.ActualHeight;

        VisualBrush clone = new VisualBrush(this.myListBox) { Stretch = Stretch.None, AutoLayoutContent = true };
        var rectangle = new Rectangle { Fill = clone, Width = this.myListBox.ActualWidth, Height = this.myListBox.ActualHeight };
        Border border = new Border { Background = Brushes.White, Width = this.myListBox.ActualWidth, Height = this.myListBox.ActualHeight };
        border.Child = rectangle;
        grid.Children.Add(border);
        Grid.SetRow(border, 1);

        scrollView.Width = this.myListBox.ActualWidth;
        scrollView.Height = this.myListBox.ActualHeight;
        scrollView.Content = grid;
        scrollView.VerticalScrollBarVisibility = ScrollBarVisibility.Hidden;

        return scrollView;
    }

Here is the GetPage override in my DocumentPaginator implementation:

public override DocumentPage GetPage(int pageNumber)
    {
        Page page = new Page();
        double z = 0.0;

        this.grid = new Grid();
        this.grid.RowDefinitions.Add(new RowDefinition());
        this.grid.RowDefinitions[0].Height = new GridLength(0, GridUnitType.Auto);

        this.grid.Children.Add(this.printViewer);
        Grid.SetRow(this.printViewer, 0);

        //Adjusting the vertical scroll offset depending on the page number
        if (pageNumber + 1 == 1) //if First Page
        {
            this.printViewer.ScrollToVerticalOffset(0);
            this.printViewer.UpdateLayout();
        }
        else if (pageNumber + 1 == _verticalPageCount) //if Last Page
        {
            if (this.printViewer.ScrollableHeight == 0) //If printing only single page and the contents fits only on one page
            {
                this.printViewer.ScrollToVerticalOffset(0);
                this.printViewer.UpdateLayout();

            }
            else if (this.printViewer.ScrollableHeight <= this.printViewer.Height) //If scrollconentheight is less or equal than scrollheight
            {
                this.printViewer.Height = this.printViewer.ScrollableHeight;
                this.printViewer.ScrollToEnd();
                this.printViewer.UpdateLayout();
            }
            else //if the scrollcontentheight is greater than scrollheight then set the scrollviewer height to be the remainder between scrollcontentheight and scrollheight
            {
                this.printViewer.Height = (this.printViewer.ScrollableHeight % this.printViewer.Height) + 5;
                this.printViewer.ScrollToEnd();
                this.printViewer.UpdateLayout();
            }
        }
        else //Other Pages
        {
            z = z + this.printViewer.Height;
            this.printViewer.ScrollToVerticalOffset(z);
            this.printViewer.UpdateLayout();
        }

        page.Content = this.grid; //put the grid into the page
        page.Arrange(new Rect(this.originalMargin.Left, this.originalMargin.Top, this.ContentSize.Width, this.ContentSize.Height));
        page.UpdateLayout();

        return new DocumentPage(page);
    }

Interestingly if I change the Fill of rectangle to a Brush instead of clone then I do not receive the exception and the outputted file is the correct size.

I have spent over a day trying to debug why this isn't working and I am hoping that someone out there has either seen a similar issue or is able to point out any mistakes I am making.

Thanks for any responses.

Answer 1

Have you checked the value of ActualWidth and ActualHeight of myListBox when the VisualBrush is being created? I don't know from where myListBox comes, but if it is not rendered by the time you are generating your xps document you may run into problems. You can try to manually force the control to render and see if it makes any difference.

Answer 2

我无法解决问题，但是使用此链接可以对WPF视觉图像进行分页打印，从而找到了合适的解决方案，可以在WPF应用程序中进行复杂视觉图像的打印。

Answer 3

It's 2016 now and it's still not fixed. The problem is using TileBrush or any descendant type ( VisualBrush in your case). If you use absolute mapping, it works, it's the relative mapping that causes the problem. Calculate the final size yourself and set Viewport to this size, ViewportUnits to Absolute . Also make sure you don't use Stretch .

Answer 4

I had to give up finding a solution with VisualBrush. If there is a GroupBox in the Visual for the brush I could never get it to produce a XPS file. It always fails with

System.ArgumentException was unhandled by user code Message=Width and Height must be non-negative. Source=ReachFramework StackTrace: at System.Windows.Xps.Serialization.VisualSerializer.WriteTileBrush(String element, TileBrush brush, Rect bounds)

The workaround was to clone the content that should go in the VisualBrush ( Is there an easy/built-in way to get an exact copy (clone) of a XAML element? ) and use that directly in a Grid instead of an VisualBrush