WPF：Visual Studio 2008 设计器中的固定文档

Question

It's a well-known bug that Visual Studio shows an error when you try to construct a FixedDocument in XAML. For example, the following snippet

<DocumentViewer>
    <FixedDocument>
        <PageContent>
            <FixedPage Width="21.0cm" Height="29.7cm">
                <TextBlock>Hello World!</TextBlock>
            </FixedPage>
        </PageContent>
    </FixedDocument>
</DocumentViewer>

compiles and runs perfectly fine, but Visual Studio shows an error in the error list ( Property 'Pages' does not support values of type 'PageContent'. ) This is quite annoying.

I'm looking for a solution that allows me to construct my documents in a XAML file in Visual Studio without getting that error message. I've found a workaround, which I'd like to share below as an answer, but I'm curious if there's a better (more elegant) solution around.

Answer 1

As a workaround, I put the DocumentViewer as well as the page into a grid:

<Grid>
    <FixedPage Width="21.0cm" Height="29.7cm" x:Name="uiPage1">
        <TextBlock>Hello World!</TextBlock>
    </FixedPage>
    <DocumentViewer>
        <FixedDocument x:Name="uiReport">
        </FixedDocument>
    </DocumentViewer>
</Grid>

Then I attach the page to the DocumentViewer in the Loaded event of the window:

VB example:

DirectCast(Me.uiPage1.Parent, Grid).Children.Remove(Me.uiPage1)
Dim content As New PageContent()
DirectCast(content, IAddChild).AddChild(Me.uiPage1)
Me.uiReport.Pages.Add(content)

C# example:

((Grid)uiPage1.Parent).Children.Remove(uiPage1);
var content = new PageContent();
((IAddChild)content).AddChild(uiPage1);
uiReport.Pages.Add(content);

Answer 2

A cleaner workaround:

[ContentProperty("Pages")]
public class XamlFixedDocument : FixedDocument
{
    private ObservableCollection<PageContent> _pages;

    public XamlFixedDocument()
    {
        this.Pages = new ObservableCollection<PageContent>();
    }

    public new ObservableCollection<PageContent> Pages
    {
        get => _pages;
        set
        {
            _pages = value;

            foreach (var page in _pages)
            {
                base.Pages.Add(page);
            }

            _pages.CollectionChanged += (o, e) =>
            {
                if (e.NewItems != null)
                {
                    foreach (PageContent page in e.NewItems)
                    {
                        base.Pages.Add(page);
                    }
                }
            };
        }
    }
}

This subclass of FixedDocument fakes a Pages property and redirect all added pages to the real Pages property in its base class.

Usage:

<doc:XamlFixedDocument xmlns:doc="clr-namespace:Hillinworks.WPF.Document">
    <PageContent>
        <FixedPage Background="White">
            <TextBlock Text="hello, world" />
        </FixedPage>
    </PageContent>
</doc:XamlFixedDocument>

Change Hillinworks.WPF.Document to the namespace where the XamlFixedDocument class is located.

This also enables design-time preview of your document.

Answer 3

I know this had already been answered, but I think this answer is nicer because it doesn't require you to add a DocumentView.

If there's a way to reference the resources by the key name and put them in the FixedDocument with XAML, please let me know. I can't seem to find a way to do that, but maybe it's possible.

Use:

var doc = System.Windows.Application.LoadComponent(new Uri("/FixedDocumentExample.xaml", UriKind.Relative)) as FixedDocument;
doc.AddPages();

Extension Method:

using System.Collections;
using System.Windows.Documents;

public static class FixedDocumentExtended {
    public static void AddPages(this FixedDocument fixedDocument) {
        var enumerator = fixedDocument.Resources.GetEnumerator();
        while (enumerator.MoveNext()) {
            var pageContent = ((DictionaryEntry)enumerator.Current).Value as PageContent;
            if (pageContent != null) {
                fixedDocument.Pages.Add(pageContent);
            }
        }
    }
}

XAML:

<FixedDocument
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <FixedDocument.Resources>
        <PageContent x:Key="page1">
            <FixedPage Width="793.76" Height="1122.56">
                <TextBlock Margin="50" Text="Page 1"/>
            </FixedPage>
        </PageContent>
        <PageContent x:Key="page2">
            <FixedPage Width="793.76" Height="1122.56">
                <TextBlock Margin="50" Text="Page 2"/>
            </FixedPage>
        </PageContent>
    </FixedDocument.Resources>
</FixedDocument>

Answer 4

So I was messing with fixed documents and I came across the same problem. and I think this is maybe even a cleaner workaround than what others have suggested.

So basically you should create a custom class derived from FixedDocument as hillin suggested, and add a property to get FixedDocument from this object's PageContents . but since these pages are now visual children of another object you should make a copy of them using XmlReader and XmlWriter classes.

[ContentProperty("Pages")]
public class CustomFixedDocument : FixedDocument
{
    private ObservableCollection<PageContent> _pages;

    public CustomFixedDocument()
    {
        this.Pages = new ObservableCollection<PageContent>();
    }

    public FixedDocument FixedDocument
    {
        get
        {
            var document = new FixedDocument();
            foreach (var p in Pages)
            {
                var copy = XamlReader.Parse(XamlWriter.Save(p)) as PageContent;
                document.Pages.Add(copy);
            }
            return document;
        }
    }

    public new ObservableCollection<PageContent> Pages
    {
        get => _pages;
        set
        {
            _pages = value;

            foreach (var page in _pages)
            {
                base.Pages.Add(page);
            }

            _pages.CollectionChanged += (o, e) =>
            {
                if (e.NewItems != null)
                {
                    foreach (PageContent page in e.NewItems)
                    {
                        base.Pages.Add(page);
                    }
                }
            };
        }
    }
}

now in the xaml you could easily create a CustomFixedDocument StaticResource and bind your DocumentViewer to the 'FixedDocument' property of it.

<Window x:Class="MyProject.DocumentWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:MyProject"
    mc:Ignorable="d"
    Title="DocumentWindow" Height="450" Width="800" Loaded="Window_Loaded">
<Window.Resources>
    <local:CustomFixedDocument x:Key="Report">
        <PageContent>
            <FixedPage Width="793.76" Height="1122.56">
                <TextBlock Margin="50" Text="Page 1"/>
            </FixedPage>
        </PageContent>
        <PageContent>
            <FixedPage Width="793.76" Height="1122.56">
                <TextBlock Margin="50" Text="Page 2"/>
            </FixedPage>
        </PageContent>
    </local:CustomFixedDocument>
</Window.Resources>
<Grid>
    <DocumentViewer x:Name="viewer" Document="{Binding Source={StaticResource Report}, Path=FixedDocument}"/>
</Grid>

Now both issues have been addressed. there is live design time preview with no compile errors and the output could be printed.