WPF列表框绑定XElement未更新

Question

I am a beginner in C# / xaml and I do not understand everything in the binding, among others if it is necessary to notify or not to refresh the view.

In my code I use XML and XElement to store data. The xml contains one list of items (Properties), each of these items contains two lists (videoStreams and audioStreams).

When I add (or delete) one video the view is not refreshed. After if I add (or delete) one audio the view is refershed. The videos and audios lists are updated. If, in the xaml code, I reverse audio and video lists, the problem is with audio.

Have you any idea about this problem?

My XML (extract)

<Root>
<Properties name="Node">
    <videoNode exclude="false">
        <rate minFrameRate="" maxFrameRate="" />
    </videoNode>
    <audioNode >
        <bitrateRange min="" max="" />
    </audioNode>
</Properties>

The xaml

    <ListBox Name="multiMaster" ItemsSource ="{Binding Elements[Properties]}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <ListBox Name="videoStreams" ItemsSource="{Binding Elements[videoNode]}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel x:Name="stackVideo" Orientation="Vertical">
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <ListBox Name="audioStreams" ItemsSource="{Binding Elements[audioNode]}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel x:Name="stackAudio" Orientation="Vertical">
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </StackPanel>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

and the add function

    foreach (XElement childElement in oMMPNode.Descendants("Properties"))
{
    if (childElement.Attribute("id").Value == profileId)
    {
        XElement newVideo = new XElement("videoNode");
        childElement.Add(newVideo);

        break;
    }
}

Answer 1

Yes, it is necessary to notify. You need to map the XML data to a set of ViewModels . These should implement INotifyPropertyChanged , and raise the corresponding event when values are changed, etc.

So, instead of XElement you would use:

public class XElementViewModel:INotifyPropertyChanged
{ 

 public XElementViewModel(XElement data)
 {
    // initialize properties 
 }
 ... 
 // here you define all needed properties of XElement that you want to expose
}