将BlockUIContainer打印到XpsDocument/FixedDocument

Question

问题

1. 如何打印具有FlowDocument的BlockUIContainer
2. 如何在FlowDocument上强制执行度量值/更新/安排？

背景

我已经生成了一个包含文本段落的FlowDocument，其中有几个来自资源字典的Rectangle元素填充了DrawingBrushes，还有一些带有自定义控件的BlockUIContainer。

当文档被转换为FixedDocument/XpsDocument时，当文档被转换为FixedDocument/XpsDocument时，或BlockUIContainer元素都不会呈现任何Rectangle或BlockUIContainer元素。

我几乎可以肯定，这是因为控件没有测量/安排，但是在转换为之前，无法弄清楚如何强制这样做。

• 我递归地遍历了LogicalTree并完成了以下操作 UIElement元素= (UIElement)d；element.Measure(Double.PositiveInfinity，Double.PositiveInfinity)；element.Arrange(新Rect(element.DesiredSize))；element.UpdateLayout()； 其中d是DependencyObject。我可以看到，在调试器中断点时，这会设置ActualWidth和ActualHeight属性。
• 我已经尝试过强制Dispatcher按照威尔♦的建议呈现。

用于打印的XpsDocument代码

public class XpsDocumentConverter
{

    public static XpsDocumentReference CreateXpsDocument(FlowDocument document)
    {
        // Need to clone the document so that the paginator can work
        FlowDocument clonedDocument = DocumentHelper.Clone<FlowDocument>(document);

        Uri uri = new Uri(String.Format("pack://temp_{0}.xps/", Guid.NewGuid().ToString("N")));
        MemoryStream ms = new MemoryStream();

        Package pkg = Package.Open(ms, FileMode.Create, FileAccess.ReadWrite);
        PackageStore.AddPackage(uri, pkg);
        XpsDocument xpsDocument = new XpsDocument(pkg, CompressionOption.Normal, uri.AbsoluteUri);

        XpsSerializationManager rsm = new XpsSerializationManager(new XpsPackagingPolicy(xpsDocument), false);
        DocumentPaginator paginator = new FixedDocumentPaginator(clonedDocument, A4PageDefinition.Default);
        rsm.SaveAsXaml(paginator);

        return new XpsDocumentReference(ms, xpsDocument);
    }

}

如您所见，我还使用了一个名为“FixedDocumentPaginator”的自定义DocumentPaginator；但是，我不会发布该代码，因为我怀疑这个问题是否存在，因为当它开始在GetPage(int pageNumber)中分页文档时，所有内容都已经转换为Visual，而且布局已经太晚了。

编辑

嗯。当我输入这个文件时，我突然想到，克隆的文档可能没有做Measure/Arrange/UpdateLayout。

问题：如何强制在FlowDocument上进行度量/更新/安排？

我可以做的一个可能的黑客是将克隆的文档显示在一个FlowDocumentViewers中(也许是屏幕外)。

另一个可能的解决方案，我刚刚了解，但没有尝试是打电话：ContextLayoutManager.From(Dispatcher.CurrentDispatcher).UpdateLayout();

ContextLayoutManager为您遍历逻辑树并更新布局。

用于克隆文档的代码

public static FlowDocument Clone(FlowDocument originalDocument)
{
    FlowDocument clonedDocument = new FlowDocument();
    TextRange sourceDocument = new TextRange(originalDocument.ContentStart, originalDocument.ContentEnd);
    TextRange clonedDocumentRange = new TextRange(clonedDocument.ContentStart, clonedDocument.ContentEnd);
    try
    {
        using (MemoryStream ms = new MemoryStream())
        {
            sourceDocument.Save(ms, DataFormats.XamlPackage);
            clonedDocumentRange.Load(ms, DataFormats.XamlPackage);
        }

        clonedDocument.ColumnWidth = originalDocument.ColumnWidth;
        clonedDocument.PageWidth = originalDocument.PageWidth;
        clonedDocument.PageHeight = originalDocument.PageHeight;
        clonedDocument.PagePadding = originalDocument.PagePadding;
        clonedDocument.LineStackingStrategy = clonedDocument.LineStackingStrategy;

        return clonedDocument;
    }
    catch (Exception)
    {               
    }

    return null;
} 

Answer 1

将此作为其他与FlowDocument/FixedDocument/XpsDocument有类似呈现问题的人的未来参考。

有几件事要注意：

• 使用上述方法时，不会克隆BlockUIContainers。直到我使用一些帮助方法将逻辑树打印出调试窗口(这些方法发布在下面--它们非常有用)之前，这一点并不明显。
• 您需要在查看器中显示文档，并在屏幕上简短地显示它。下面是我为自己编写的帮助方法。

ForceRenderFlowDocument

private static string ForceRenderFlowDocumentXaml = 
@"<Window xmlns=""http://schemas.microsoft.com/netfx/2007/xaml/presentation""
          xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml"">
       <FlowDocumentScrollViewer Name=""viewer""/>
  </Window>";

public static void ForceRenderFlowDocument(FlowDocument document)
{
    using (var reader = new XmlTextReader(new StringReader(ForceRenderFlowDocumentXaml)))
    {
        Window window = XamlReader.Load(reader) as Window;
        FlowDocumentScrollViewer viewer = LogicalTreeHelper.FindLogicalNode(window, "viewer") as FlowDocumentScrollViewer;
        viewer.Document = document;
        // Show the window way off-screen
        window.WindowStartupLocation = WindowStartupLocation.Manual;
        window.Top = Int32.MaxValue;
        window.Left = Int32.MaxValue;
        window.ShowInTaskbar = false;
        window.Show();
        // Ensure that dispatcher has done the layout and render passes
        Dispatcher.CurrentDispatcher.Invoke(DispatcherPriority.Loaded, new Action(() => {}));
        viewer.Document = null;
        window.Close();
    }
}

编辑：--我刚刚将window.ShowInTaskbar = false添加到方法中，就像您速度快一样--您可以看到窗口出现在任务栏中。

用户永远不会“看到”窗口，因为它位于Int32.MaxValue的屏幕外--这在早期多媒体创作中很常见(例如，Macromedia/Adobe )。

对于搜索和查找这个问题的人，我可以告诉您，没有其他方法可以强制文档呈现。

可视化和逻辑树帮助器

public static string WriteVisualTree(DependencyObject parent)
{
    if (parent == null)
        return "No Visual Tree Available. DependencyObject is null.";

    using (var stringWriter = new StringWriter())
    using (var indentedTextWriter = new IndentedTextWriter(stringWriter, "  "))
    {               
        WriteVisualTreeRecursive(indentedTextWriter, parent, 0);
        return stringWriter.ToString();
    }
}

private static void WriteVisualTreeRecursive(IndentedTextWriter writer, DependencyObject parent, int indentLevel)
{
    if (parent == null)
        return;

    int childCount = VisualTreeHelper.GetChildrenCount(parent);
    string typeName = parent.GetType().Name;
    string objName = parent.GetValue(FrameworkElement.NameProperty) as string;

    writer.Indent = indentLevel;
    writer.WriteLine(String.Format("[{0:000}] {1} ({2}) {3}", indentLevel, 
                                                              String.IsNullOrEmpty(objName) ? typeName : objName, 
                                                              typeName, childCount)
                    );

    for (int childIndex = 0; childIndex < childCount; ++childIndex)
        WriteVisualTreeRecursive(writer, VisualTreeHelper.GetChild(parent, childIndex), indentLevel + 1);
}

public static string WriteLogicalTree(DependencyObject parent)
{
    if (parent == null)
        return "No Logical Tree Available. DependencyObject is null.";

    using (var stringWriter = new StringWriter())
    using (var indentedTextWriter = new IndentedTextWriter(stringWriter, "  "))
    {
        WriteLogicalTreeRecursive(indentedTextWriter, parent, 0);
        return stringWriter.ToString();
    }
}

private static void WriteLogicalTreeRecursive(IndentedTextWriter writer, DependencyObject parent, int indentLevel)
{
    if (parent == null)
        return;

    var children = LogicalTreeHelper.GetChildren(parent).OfType<DependencyObject>();
    int childCount = children.Count();

    string typeName = parent.GetType().Name;
    string objName = parent.GetValue(FrameworkElement.NameProperty) as string;

    double actualWidth = (parent.GetValue(FrameworkElement.ActualWidthProperty) as double?).GetValueOrDefault();
    double actualHeight = (parent.GetValue(FrameworkElement.ActualHeightProperty) as double?).GetValueOrDefault();

    writer.Indent = indentLevel;
    writer.WriteLine(String.Format("[{0:000}] {1} ({2}) {3}", indentLevel,
                                                              String.IsNullOrEmpty(objName) ? typeName : objName,
                                                              typeName, 
                                                              childCount)
                    );

    foreach (object child in LogicalTreeHelper.GetChildren(parent))
    {
        if (child is DependencyObject)
            WriteLogicalTreeRecursive(writer, (DependencyObject)child, indentLevel + 1);
    }

}

使用

#if DEBUG
    Debug.WriteLine("--- Start -------");
    Debug.WriteLine(VisualAndLogicalTreeHelper.WriteLogicalTree(document));
    Debug.WriteLine("--- End -------");
#endif

Answer 2

我找到了这个解决方案这里，它帮助我打印的FlowDocment，而不必渲染它的screen...So -我希望它可以帮助你！！

String copyString = XamlWriter.Save(flowDocViewer.Document);
FlowDocument copy = XamlReader.Parse(copyString) as FlowDocument;