In MVVM, is every ViewModel coupled to just one Model?

Question

In an MVVM implementation, is every ViewModel coupled to just one Model?

I am trying to implement the MVVM pattern in a project but I found

Answer 1

Usually there is one ViewModel per Model. These ViewModels contain the logic to handle the model's data. On the other side every view has it's own view model, too. So this means:

class ModelA 
{
    bool TestValue{get;set;}
}
class ViewModelA
{
    ValueViewModel TestValue{get; private set;}

    public ViewModelA(ModelA model) 
    {
        base.Model = model;
        this.Initialize();
    }
}

class ModelB 
{
    string Username;
}
class ViewModelB
{
    ValueViewModel Username{get; private set;}

    public ViewModelB(ModelB model) 
    {
        base.Model = model;
        this.Initialize();
    }
}

These are the ViewModels that encapsulate the models. The views have their own ViewModels:

public ViewModelForExactlyOneView
{
    public ViewModelA{get;set;}
    public ViewModelB{get;set;}
}

To answer your question, ViewModel1 refers to ViewModelA and ViewModelB. The View therefore can get it's data from ViewModel1.ViewModelA.TestValue.