Question

My situation is slightly different than from other posts and I was not able to solve it with the other trhreads. So that why I ask.

I have a class that is obtained from deserializing an XML like:

<?xml version="1.0" encoding="UTF-8"?>
<node>
    <leaf>
        <name>node 1</name>
        <text>text 1</text>
        <url>url 1</url>
    </leaf>
    <leaf>
        <name>node 2</name>
        <text>text 2</text>
        <url>url 2</url>
    </leaf>
</node>

so the class is:

[XmlRoot("node")]
public class csNodeList
{
    public csNodeList()
    {
        Leaf = new csLeafCollection();
    }

    [XmlElement("leaf")]
    public csLeafCollection Leaf
    {
        get;
        set;
    }
}

public class csLeaf
{
    public csLeaf()
    {
        Name ="";
        Description = "";
        Address = "";
    }

    [XmlElement("name")]
    public string Name
    {
        get;
        set;
    }

    [XmlElement("text")]
    public string Description
    {
        get;
        set;
    }

    [XmlElement("url")]
    public string Address
    {
        get;
        set;
    }
}

public class csLeafCollection : System.Collections.ObjectModel.ObservableCollection<csLeaf>
{
}

Then I have 2 Views, one to show all the leafs and one to edit one leaf. I’ve implemented commit and rollback so I use messaging back and forth to pass the new values and I store the old ones.

To do so I copy the objects a a backup variable and then I modify the ones associated via binding to the XAML view, in this way (in theory) any change to the ViewModel data should be reflected.
Also is better because if I commit the changes I just discard the backup variables (this is 90% of the times) and if I need to roll back I copy back from the backup variables.

MainView:

public const string listPropertyName = "list";
private csNodeList _list = new csNodeList();
public csNodeList list
{
    get
        {
        return _list;
    }
    set
    {
        Set(listPropertyName, ref _list, value, false);
    }
}

Using the message I send back the new values of a node and I put them in the correct position:

private void DoSomething(csMessage message)
{
    csMessage rmessage;
    if (message != null)
    {
        switch (message.destination)
        {
            case csMessage.e2MessageDest.updateNode:
            //_editP should be fine.
            list.Leaf[list.Leaf.IndexOf(_editP)].Name = ((csLeaf)message.payload).Name;
            list.Leaf[list.Leaf.IndexOf(_editP)].Text= ((csLeaf)message.payload).Text;
            list.Leaf[list.Leaf.IndexOf(_editP)].Address = ((csLeaf)message.payload).Address;
            RaisePropertyChanged(listPropertyName , null, _list, true);
            break;
        }
    }
}

The code is executed correctly and the item is changed.

BUT the RaisePropertyChanged is ignored. I’ve tried even just the one with the listPropertyName without any change.

If I save the changes exit from the app and get back I see the new value correctly stored

Can you please help me?

Thanks,
Massimo

Answer 1

Thank you everyone for the help.
Investigating your suggestion I’ve found a slightly different solution; as you correctly said the issue is that the leaf fields are not “observable” so they do not generate a notification event.

I’ve noticed that if I add or Delete a profile the binding is updated.

So what I’ve decided to do is not to edit directly the leafs but to replace the node.
What I do not like is that I have to create a node to replace the old one and this allocates a little bit more memory… but for small data like the one I have it can work without any major impact on the app performance/memory foot print.

Here is what I do:

        csLeaf _leaf = new slLeaf();
        _leaf.Name = ((csLeaf)message.payload).Name; 
        _leaf.Text= ((csLeaf)message.payload).Text; 
        _leaf.URL = ((csLeaf)message.payload).Address; 
        list.Leaf[list.Leaf.IndexOf(_editP)] = _leaf;

To optimized readabilty of code I’ve enhanced it adding a constructor with 3 parameters so that the code can be:

        csLeaf _leaf = new slLeaf(((csLeaf)message.payload).Name, ((csLeaf)message.payload).Text, ((csLeaf)message.payload).Address);
        list.Leaf[list.Leaf.IndexOf(_editP)] = _leaf;

The constructor is:

public csLeaf(string _name, string _description, string _address) 
{ 
    Name = _name; 
    Description = _description;
    Address = _address; 
}