在 DataContext C# WPF 之外使用绑定的 CheckBox 值

Question

I want to use the status of a checkbox in another class. Unfortunately, this does not quite work.

Here is my code example: Please note: All Bindings, OnPropertyChanged and the RelayCommand, which has the Icommand, were implemented correctly and work. But not in here, to make it easier to read.

MainWindow XAML:

<CheckBox Content="Select or not" IsChecked="{Binding IsSelected}"/>

<Button Content="Test" Command="{Binding ButtonCommand}">

HomeViewModel (DataContext):

private bool _isSelected;
public bool IsSelected
{
    get { return _isSelected; }
    set
    {
        if (_isSelected != value)
        {
            _isSelected = value;
            OnPropertyChanged(nameof(IsSelected));
        }
    }
}

private void DoJob(object sender)
{
    Class1 class1 = new Class1();
    class1.Method();
}

Class1:

HomeViewModel viewModel = new HomeViewModel();

public void Method()
{
    if (viewModel.IsSelected)
    {

    }
}

How can I use the status of IsSelected in other classes?

Unfortunately I can't access it directly (I don't know why).

Thanks for your help.

Answer 1

It looks like you are creating new instance of HomeViewModel in your Class1. Is that what you intended to do? If you want to work with the HomeViewModel you are creating Class1 from you need to pass the reference to it. Something like this:

HomeViewModel:

private void DoJob(object sender)
{
    Class1 class1 = new Class1(this);
    class1.Method();
}

Class1:

//constructor
public Class1(HomeViewModel _viewModel)
{
    viewModel = _viewModel;
}

HomeViewModel viewModel;

public void Method()
{
    if (viewModel.IsSelected)
    {
        
    }
}

Sorry if I missed the point here.

EDIT: Assuming that your MainWindowViewModel is actually HomeViewModel