首先，我不确定我是否正确地表达了这个标题。通过UserControls添加了ViewModel，我通过搜索VisualTree找到它们并将它们添加到ObservableCollection<Grid>。我想要做的是将我从UserControl检索到的VisualTree的每个实例打印到FixedDocument，但每个UserControl都在一个页面上，直到它填满该页面并转到下一页。
以下是我当前打印按钮的代码点击事件：
private async void btnPrint_Click(object sender, RoutedEventArgs e)
{
try
{
if (tabMain.Items.Count > 0)
{
tab = new TabLayout();
tab.Payslip = new ObservableCollection<Grid>();
foreach (var grid in FindVisualChildren<Grid>(this))
{
if (grid.Name == "pdfFile")
{
tab.Payslip.Add(grid);
}
}
FrameworkElement toPrint = new FrameworkElement();
PrintDialog printDialog = new PrintDialog();
PrintCapabilities capabilities = printDialog.PrintQueue.GetPrintCapabilities(printDialog.PrintTicket);
Size pageSize = new Size(printDialog.PrintableAreaWidth, printDialog.PrintableAreaHeight);
Size visibleSize = new Size(capabilities.PageImageableArea.ExtentWidth, capabilities.PageImageableArea.ExtentHeight);
FixedDocument fixedDoc = new FixedDocument();
StackPanel panel = new StackPanel(); //was trying to stack them in a stackpanel first but it threw an exception about same instance of usercontrol blah blah...
foreach (var doc in tab.Payslip.ToList())
{
double yOffset = 0;
doc.Measure((new Size(double.PositiveInfinity, double.PositiveInfinity)));
doc.Arrange(new Rect(new Point(0, 0), doc.DesiredSize));
Size size = doc.DesiredSize;
while (yOffset < size.Height)
{
VisualBrush vb = new VisualBrush(doc);
vb.Stretch = Stretch.None;
vb.AlignmentX = AlignmentX.Left;
vb.AlignmentY = AlignmentY.Top;
vb.ViewboxUnits = BrushMappingMode.Absolute;
vb.TileMode = TileMode.None;
vb.Viewbox = new Rect(0, yOffset, visibleSize.Width, visibleSize.Height);
FixedPage page = new FixedPage();
PageContent pageContent = new PageContent();
((IAddChild)pageContent).AddChild(page);
fixedDoc.Pages.Add(pageContent);
page.Width = fixedDoc.DocumentPaginator.PageSize.Width;
page.Height = fixedDoc.DocumentPaginator.PageSize.Height;
Canvas canvas = new Canvas();
FixedPage.SetLeft(canvas, capabilities.PageImageableArea.OriginWidth);
FixedPage.SetTop(canvas, capabilities.PageImageableArea.OriginHeight);
canvas.Width = visibleSize.Width;
canvas.Height = visibleSize.Height;
canvas.Background = vb;
page.Children.Add(canvas);
yOffset += visibleSize.Height;
}
}
//printDialog.PrintDocument(fixedDoc.DocumentPaginator, "");
ShowPrintPreview(fixedDoc);
}
}
catch(Exception ex)
{
var exceptionDialog = new MessageDialog
{
Message = { Text = ex.ToString() }
};
await DialogHost.Show(exceptionDialog, "RootDialog");
}
}
这是我尝试打印三个标签时的样子（UserControls托管在标签中）： As you can see here it prints three separate pages
我想在一个页面上全部三个，如果我打印10个标签，那么它应该填满第一页并继续下一页。
上次我问过类似的问题时，我被质疑是否编写了代码。此代码的各个部分来自FixedDocument上类似的StackOverflow个问题，但它已被编辑到实际适合我的程度。所以是的，我知道FixedPage中的foreach引用是什么导致创建三个单独的页面，我确实理解了代码。
要点：
我想知道的是如何从每个UserControls获取Tab到一个页面直到它完整，而没有得到“指定元素已经是另一个元素的逻辑子元素。”断开连接它首先。“错误。
答案 0 :(得分：0)
我最终使用ItemsControl将ObservableCollection Controls ItemsControl作为列表，并使用此XpsDocumentWriter方法从public void PrintItemsTo(ItemsControl ic, String jobName)
{
PrintDialog dlg = new PrintDialog();
dlg.UserPageRangeEnabled = true;
if (dlg.ShowDialog().GetValueOrDefault())
{
PageRange range = dlg.PageRange;
// range check - user selection starts from 1
if (range.PageTo > ic.Items.Count)
range.PageTo = ic.Items.Count;
dlg.PrintQueue.CurrentJobSettings.Description = jobName;
XpsDocumentWriter xdw = PrintQueue.CreateXpsDocumentWriter(dlg.PrintQueue);
if (dlg.UserPageRangeEnabled == false || range.PageTo < range.PageFrom)
WriteAllItems(ic, xdw);
else
WriteSelectedItems(ic, xdw, range);
}
}
private void WriteAllItems(ItemsControl ic, XpsDocumentWriter xdw)
{
PageRange range = new PageRange(1, ic.Items.Count);
WriteSelectedItems(ic, xdw, range);
}
private void WriteSelectedItems(ItemsControl ic, XpsDocumentWriter xdw, PageRange range)
{
IItemContainerGenerator generator = ic.ItemContainerGenerator;
// write visuals using a batch operation
VisualsToXpsDocument collator = (VisualsToXpsDocument)xdw.CreateVisualsCollator();
collator.BeginBatchWrite();
if (WritePageRange(collator, generator, range))
collator.EndBatchWrite();
}
private bool WritePageRange(VisualsToXpsDocument collator, IItemContainerGenerator generator, PageRange range)
{
// Get the generator position of the first data item
// PageRange reflects user's selection starts from 1
GeneratorPosition startPos = generator.GeneratorPositionFromIndex(range.PageFrom - 1);
// If PageFrom > PageTo, print in reverse order
// UPDATE: never occurs; PrintDialog always 'normalises' the PageRange
GeneratorDirection direction = (range.PageFrom <= range.PageTo) ? GeneratorDirection.Forward : GeneratorDirection.Backward;
using (generator.StartAt(startPos, direction, true))
{
for (int numPages = Math.Abs(range.PageTo - range.PageFrom) + 1; numPages > 0; --numPages)
{
bool newlyRealized;
// Get or create the child
UIElement next = generator.GenerateNext(out newlyRealized) as UIElement;
if (newlyRealized)
{
generator.PrepareItemContainer(next);
}
// The collator doesn't like ContentPresenters and produces blank pages
// for pages 2-n. Finding the child of the ContentPresenter and writing
// that solves seems to solve the problem
if (next is ContentPresenter)
{
ContentPresenter presenter = (ContentPresenter)next;
presenter.UpdateLayout();
presenter.ApplyTemplate(); // not sure if this is necessary
DependencyObject child = VisualTreeHelper.GetChild(presenter, 0);
if (child is UIElement)
next = (UIElement)child;
}
try
{
collator.Write(next);
}
catch
{
// if user prints to Microsoft XPS Document Writer
// and cancels the SaveAs dialog, we get an exception.
return false;
}
}
}
return true;
}
打印。
SUM(
NULL:[Accounting Date].[Calendar].CurrentMember,
IIF(
[Measures].[Amount] < 0,
NULL,
[Measures].[Amount]
)
)
PrintItemsTo（），显示PrintDialog以打印到任何打印机，而WriteAllItems显示一个对话框以另存为PDF。