在wpf中绑定不起作用，看不到为什么

Question

I have a wpf app I'm using some xaml code that should let me view pdf files, I just started to use data biding and don't figure way this not works for me.

here m XAML:

<Grid>
<telerik:RadPdfViewerToolBar RadPdfViewer="{Binding ElementName=pdfViewer, Mode=OneTime}" SignaturePanel="{Binding ElementName=signaturePanel, Mode=OneTime}"/>
<telerik:SignaturePanel x:Name="signaturePanel" PdfViewer="{Binding ElementName=pdfViewer, Mode=OneWay}" Grid.Row="1"/>
<telerik:RadPdfViewer x:Name="pdfViewer" DocumentSource="{Binding Path=PathOfPdf, Mode=TwoWay}"  DataContext="{Binding CommandDescriptors, ElementName=pdfViewer}" telerik:RadPdfViewerAttachedComponents.RegisterSignSignatureDialog="True" telerik:RadPdfViewerAttachedComponents.RegisterFindDialog="True" Grid.Row="2" telerik:RadPdfViewerAttachedComponents.RegisterSignaturePropertiesDialog="True" telerik:RadPdfViewerAttachedComponents.RegisterContextMenu="True"/>
<Grid>

And here code behind:

public partial class Page2 : Page, INotifyPropertyChanged
{
public Page2()
    {
        InitializeComponent();
        DataContext = this;
     }  

private string _pathOfPdf= @"D:\MyFile.pdf";

    public string PathOfPdf
    {
        get{ return _pathOfPdf; }
        set{
            if (_pathOfPdf != value)
            {
                _pathOfPdf = value;
                OnPropertyChanged();
            }
        }

    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }   
}

If I'm not using Biding it works fine. I if I do(on XAML):

DataContext="D:\\MyFile.pdf" it shows the pdf

Answer 1

You need to either set the DataContext of the control or the source of the binding to the Page where the source property is defined:

<telerik:RadPdfViewer x:Name="pdfViewer"
                      DocumentSource="{Binding Path=PathOfPdf, RelativeSource={RelativeSource AncestorType=Page}}" />