Question

I would like to create a ViewModel Class to retrieve the values from the Database.
My goal is to retrieve the Values of Usage of RAM (Ram total & Ram available) from my DB Table and then display it on my View.

This is what I have done so far on my ViewModel Class

public class RamViewModel : INotifyPropertyChanged
{
    float _ramTotal;
    float _ramUsed;

    public float RamTotal
    {
        get { return _ramTotal; }
        set { _ramTotal = value; RaisePropertyChanged("RamTotal"); }
    }

    public float RamUsed
    {
        get { return _ramUsed; }
        set { _ramUsed = value; RaisePropertyChanged("RamUsed"); }
    }

    private void RaisePropertyChanged(string p)
    {
        throw new NotImplementedException();
    }
  }

when I build the class, I got this error stating, ” ViewModel.RamViewModel Does not implement interface member ‘System.ComponentModel.INotifyPropertyChanged.PropertyChanged'”

How to overcome this error

Answer 1

INotifyPropertyChanged is an interface with one member that needs to be included in your class definition:

    public event PropertyChangedEventHandler PropertyChanged;

You should also change the code in RaisePropertyChanged to not throw an exception, by implementing the actual functionality:

    private void RaisePropertyChanged(string p)
    {
        if (null != PropertyChanged) PropertyChanged(this, new PropertyChangedEventArgs(p));
    }