问题描述
问题
- 如何打印具有
BlockUIContainer的 FlowDocument? - 如何强制对 FlowDocument 进行度量/更新/安排?
- How do you print a FlowDocument that have
BlockUIContainer? - How can I force a Measure/Update/Arrange on a FlowDocument?
背景
我有一个生成的 FlowDocument，其中包含来自资源字典的 DrawingBrushes 和 BlockUIContainer 带有自定义控件.
I have a generated FlowDocument with paragraphs of text with a few Rectangle elements filled DrawingBrushes from a resource dictionary and BlockUIContainer with custom controls.
在任何 FlowDocument* 控件中查看时，文档都正确呈现但是当文档转换为 FixedDocument/XpsDocument 时，Rectangle 或 BlockUIContainer 元素呈现.
The document renders correctly when viewed in any of the FlowDocument* controls HOWEVER when the document is converted to a FixedDocument/XpsDocument, none of the Rectangle or BlockUIContainer elements render.
我几乎可以肯定这是因为控件没有被测量/排列，但是在它被转换为 XpsDocument 之前无法弄清楚如何强制它发生.
I'm almost certain it is because the control has not been measured/arranged, however cannot figure out how to force that to happen before it is converted to the XpsDocument.
我递归地遍历了
LogicalTree并完成了以下操作，
UIElement element = (UIElement)d;
element.Measure(new Size(Double.PositiveInfinity, Double.PositiveInfinity));
element.Arrange(new Rect(element.DesiredSize));
element.UpdateLayout();
其中 d 是 DependencyObject.我可以看到这在调试器中设置断点时设置了 ActualWidth 和 ActualHeight 属性.
where d is a DependencyObject. I can see that this sets the ActualWidth and ActualHeight properties when break-pointed in the debugger.
我尝试强制 Dispatcher 按照 Will ♦ 的建议进行渲染.
I have tried forcing the Dispatcher to render as suggested by Will ♦.
用于打印 XpsDocument 的代码
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，因为我怀疑问题是否存在，因为当它开始在 GetPage(int pageNumber) 中对文档进行分页时，所有内容都已转换为 Visual布局太晚了.
As you can see I'm also using a custom DocumentPaginator named 'FixedDocumentPaginator'; however I will not post that code as I doubt the issue is there as by the time it starts paginating the document in GetPage(int pageNumber) everything has already been converted a Visual and it is too late for layout.
编辑
嗯.当我输入这个时，我突然想到克隆的文档可能没有完成Measure/Arrange/UpdateLayout.
Hmm. As I typed this, a thought just occurred to me that the cloned document may not have had a Measure/Arrange/UpdateLayout done.
问题:如何强制对 FlowDocument 进行度量/更新/安排?
Question: How can I force a Measure/Update/Arrange on a FlowDocument?
我可以工作的一个可能的技巧是在 FlowDocumentViewers 之一(可能在屏幕外)中显示克隆的文档.
A possible hack that I could work would be to show the cloned document in one of the FlowDocumentViewers (perhaps off-screen).
我刚刚了解到但尚未尝试的另一种可能的解决方案是调用:ContextLayoutManager.From(Dispatcher.CurrentDispatcher).UpdateLayout();
Another possible solution that I just learnt about and haven't tried would be to call: ContextLayoutManager.From(Dispatcher.CurrentDispatcher).UpdateLayout();
ContextLayoutManager 为您遍历逻辑树并更新布局.
ContextLayoutManager walks the logical tree for you and updates the layout.
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;
}
推荐答案
将此作为未来参考，供其他在 FlowDocument/FixedDocument/XpsDocument 中遇到类似渲染问题的人使用.
Posting this as future reference for others that are having similar rendering issues with FlowDocument/FixedDocument/XpsDocument.
需要注意的几点:
- 使用上述方法时，
BlockUIContainers不会被克隆.这并不是很明显，直到我使用一些辅助方法将逻辑树打印出调试窗口(这些方法在下面发布 - 它们非常有用).- 您需要在查看器中显示文档并在屏幕上简要显示它.下面是我为我写的帮助方法.
BlockUIContainersare not cloned when you use the above method. This was not immediately obvious until I printed the logical tree out the debug window using some helper methods (these methods are posted below - they are incredibly useful).- You need to display the document in a viewer and briefly show it on screen. Below is the helper method that I wrote to do this for me.
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();
}
}
我刚刚将 window.ShowInTaskbar = false 添加到方法中，就好像您很快可以看到窗口出现在任务栏中一样.
I just added window.ShowInTaskbar = false to the method as if you were quick you could see the window appear in the taskbar.
用户永远不会看到"窗口，因为它位于 Int32.MaxValue 的屏幕外——这是早期多媒体创作(例如 Macromedia/Adobe导演).
The user will never "see" the window as it is positioned way off-screen at Int32.MaxValue - a trick that was common back in the day with early multimedia authoring (e.g. Macromedia/Adobe Director).
对于搜索和发现此问题的人，我可以告诉您没有其他方法可以强制呈现文档.
For people searching and finding this question, I can tell you that there is no other way to force the document to render.
视觉和逻辑树助手
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
这篇关于将 BlockUIContainer 打印到 XpsDocument/FixedDocument的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！