Vfrdtyky

im new to WPF MVVM

i have 3 classes here (All classes have same BaseParent):

---- The Problem is ---->
Whenever i set my BaseParents GroupContent in [DPropertyViewModel], it doesnt update my ConsoleText in [DConsoleViewModel].

Model:

 public class BaseDParent

{

    public string GroupType { get; set; } = "None";



    public string GroupName { get; set; } = "None";



    public string GroupContent

    {

        get => _groupcontent;

        set

        {

            _groupcontent = value;

            SetContent();

        }

    }

    private string _groupcontent;}

ViewModel:

 public class DConsoleViewModel : DNotify

{

    public BaseDParent DElement

    {

        get => _delement;

        set

        {

            _delement = value;

            NotifyPropertyChanged();

        }

    }

    private BaseDParent _delement;



    public string ConsoleText

    {

        get => DElement.GroupContent;

        set

        {

            DElement.GroupContent = value;

            NotifyPropertyChanged();

        }

    }}

and here is where i change my BaseParents GroupContent:

public class DPropertyViewModel : DNotify

{

    public BaseDParent DElement

    {

        get => _delement;

        set

        {

            _delement = value;

            NotifyPropertyChanged();

        }

    }

    private BaseDParent _delement;



    public string Level { get; set; } = "0"; 

    public string Property { get; set; } = "Property"; 

    public string Value { get; set; } = "-Null-";



    public void SetDElementPropertyValue()

    {

        string startline = " " + DElement.GroupType + " " + DElement.GroupName + DHelper.NewLine();

        string subpropline = DHelper.NewLine() + Level + " " + Property + " ";



        int start = DElement.GroupContent.IndexOf(startline);



        int propstart = DElement.GroupContent.IndexOf(subpropline, start - 3) + subpropline.Length;

        int propnext = DElement.GroupContent.IndexOf(DHelper.NewLine(), propstart);

        string propvalue = DElement.GroupContent.Substring(propstart, propnext - propstart);



        string toremove = subpropline + propvalue + DHelper.NewLine();

        int toaddindex = DElement.GroupContent.IndexOf(toremove);

        DElement.GroupContent = DElement.GroupContent.RemoveSub(toremove);



        string toadd = subpropline + Value + DHelper.NewLine();

        DElement.GroupContent = DElement.GroupContent.Insert(toaddindex, toadd);

    }

}

Thanks for your help :)

The INotifyPropertyChanged interface is used to notify clients, typically binding clients, that a property value has changed. - Microsoft Docs on INotifyPropertyChanged

Your model BaseDParent is where you should be implementing INotifyPropertyChanged because this is where the values are changing, not in the ViewModel.

You can then remove ConsoleText from your ViewModel and bind directly to BaseDParent.GroupContent for your output.

As it currently stands, your DElement property on DConsoleViewModel is raising changes relating to the object reference itself. e.g. from null to a constructed version of BaseDParent.

Microsoft Docs on the subject: https://docs.microsoft.com/en-us/dotnet/api/system.componentmodel.inotifypropertychanged?view=netframework-4.7.2