如果返回的值为Null,如何使PriorityBinding失败？

public class ValueIsNullException : Exception
{
    public ValueIsNullException(string message) : base(message)
    {
    }
}

public class MyService
{
    public object GetValue()
    {
        // 如果返回的值为Null，抛出异常
        throw new ValueIsNullException("返回的值为Null");
    }
}

public class MyController
{
    private MyService _myService;

    public MyController(MyService myService)
    {
        _myService = myService;
    }

    public void MyMethod()
    {
        try
        {
            object value = _myService.GetValue();
            // 绑定优先级
            PriorityBinding priorityBinding = new PriorityBinding();
            priorityBinding.Bind(value);
        }
        catch (ValueIsNullException ex)
        {
            // 处理异常，使PriorityBinding失败
            // ...
        }
    }
}

public class MyService
{
    public int? GetValue()
    {
        // 如果返回的值为Null，返回null
        return null;
    }
}

public class MyController
{
    private MyService _myService;

    public MyController(MyService myService)
    {
        _myService = myService;
    }

    public void MyMethod()
    {
        int? value = _myService.GetValue();
        if (value == null)
        {
            // 处理返回值为Null的情况，使PriorityBinding失败
            // ...
        }
        else
        {
            // 绑定优先级
            PriorityBinding priorityBinding = new PriorityBinding();
            priorityBinding.Bind(value.Value);
        }
    }
}

public class MyService
{
    public int GetValue()
    {
        // 如果返回的值为Null，返回默认值0
        return 0;
    }
}

public class MyController
{
    private MyService _myService;

    public MyController(MyService myService)
    {
        _myService = myService;
    }

    public void MyMethod()
    {
        int value = _myService.GetValue();
        // 绑定优先级
        PriorityBinding priorityBinding = new PriorityBinding();
        priorityBinding.Bind(value);
    }
}