从运行任务中获取变量并显示在视图上

问：

当调用 MyActionFunc 时，下面的代码可以正常执行，但当函数位于另一个类中时则不能。MessageBox 显示正确的字符串，但未显示在视图中。我错过了什么？

class ViewModel : INotifyPropertyChanged
{
    public MyCommand ActionCommand
    {
        get;
        set;
    }

    public event PropertyChangedEventHandler PropertyChanged;
    
    protected void OnPropertyChanged([CallerMemberName] string propertyname = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyname));
    }

    public ViewModel()
    {
        ActionCommand = new MyCommand();
        ActionCommand.CanExecuteFunc = obj => true;
       // ActionCommand.ExecuteFunc = MyActionFunc;
        ActionCommand.ExecuteFunc = MyClass.MyActionFunc;
    }
   
    private string myname;
    public string myName
    {
        get => myname;
        set { myname = value;; OnPropertyChanged(); }
    }

    public void MyActionFunc(object parameter)
    {
        myName = "Fred";
    }
}
class MyClass
{
    public static void MyActionFunc(object parameter)
    {
        ViewModel name = new ViewModel();
        name.myName = "Fred";
        MessageBox.Show(name.myName);
    }
}

...以及与文本框的绑定

        <TextBox Name="textBox" Grid.Column="1"  Grid.Row="1" Text="{Binding Path=myName,  Mode=OneWay, UpdateSourceTrigger=PropertyChanged}"/>