CODEWITHSUNDEEP
c#wpfconvertersmarkup-extensions
MCRXB
MCRXB

Reputation: 109

Creating Markup Extension with Converter

I'm trying to create a Markup Extension that will take a string of HTML, convert it to a FlowDocument, and return the FlowDocument. I'm fairly new to creating Markup Extensions and I'm hoping this will be obvious to someone with more experience. Here is my code:

[MarkupExtensionReturnType(typeof(FlowDocument))]
public class HtmlToXamlExtension : MarkupExtension
{
    public HtmlToXamlExtension(String source)
    {
        this.Source = source;
    }

    [ConstructorArgument("source")]
    public String Source { get; set; }

    public Type LocalizationResourceType { get; set; }

    public override object ProvideValue(IServiceProvider serviceProvider)
    {
        if (this.Source == null)
        {
            throw new InvalidOperationException("Source must be set.");
        }

        FlowDocument flowDocument = new FlowDocument();
        flowDocument.PagePadding = new Thickness(0, 0, 0, 0);
        string xaml = HtmlToXamlConverter.ConvertHtmlToXaml(Source.ToString(), false);

        using (MemoryStream stream = new MemoryStream((new ASCIIEncoding()).GetBytes(xaml)))
        {
            TextRange text = new TextRange(flowDocument.ContentStart, flowDocument.ContentEnd);
            text.Load(stream, DataFormats.Xaml);
        }

        return flowDocument;
    }
}

Update: Here is the XAML.

<RadioButton.ToolTip>
    <FlowDocumentScrollViewer Document="{ext:HtmlToXaml Source={x:Static res:ExtrudeXaml.RadioButtonCreateBody_TooltipContent}}" ScrollViewer.VerticalScrollBarVisibility="Hidden" />
</RadioButton.ToolTip>

And my VS error list:

Upvotes: 4

Views: 2771

Answers (3)

scor4er
scor4er

Reputation: 1589

It helped to me to install the .NET 4.7 (Developer Pack), I've seen this bug at .NET 4.6 but after upgrading it's gone.

Upvotes: 0

The Smallest
The Smallest

Reputation: 5783

You implemented you MarkupExtension without default constructor: So you have 2 options:

  1. Delete your specific constructor (Anyway you set Source directly)

  2. Change invocation of you HtmlToXamlExtension if you remove Source= part, then Wpf will try to find constructor matching all unnamed fields right after ext:HtmlToXaml part:

    <RadioButton.ToolTip>
  <FlowDocumentScrollViewer 
         Document="{ext:HtmlToXaml {x:Static res:ExtrudeXaml.RadioButtonCreateBody_TooltipContent}}" 
         ScrollViewer.VerticalScrollBarVisibility="Hidden" />
</RadioButton.ToolTip>

    UPD: Even though it works, but MSDN says, that you should have default constructor

Hope it helps.

Upvotes: 3

Alexis
Alexis

Reputation: 825

You should create default constructor for your markup extension, and everything will be fine.

Upvotes: 0

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