Xamarin.ios MvvmCross:UIDatePicker时间更改不会触发绑定

我正在使用Xamarin.iOS和MvvmCross构建页面视图。我有一个UIView，其中包含DateAndTime模式下的UIDatePicker。如果我在绑定vm属性中设置断点并更改日期，我可以看到绑定触发。如果我更改了时间，但是绑定属性上没有任何更新

代码如下：

[Register("EditJobViewJobView")]
public class EditJobView : MvxViewController
{
    public new EditJobViewModel ViewModel
    {
        get { return (EditJobViewModel)base.ViewModel; }
    }

    private const float _leftMargin = 6;
    private const float _labelHeight = 20;
    private const float _pickerHeight = 28;

    private readonly UIFont _labelFont = UIFont.BoldSystemFontOfSize(18f);
    private readonly UIFont _controlFont = UIFont.SystemFontOfSize(18f);

    private readonly UIView _paddingInsert = new UIView(new RectangleF(0, 0, 4, 0));

    private int _currentTop = 0;

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();

        View = new UIView() { BackgroundColor = UIColor.White };

        NavigationItem.SetRightBarButtonItem(new UIBarButtonItem("Save", UIBarButtonItemStyle.Bordered,
            (sender, args) => ViewModel.OkCommand.Execute(null)), true);

        // ios7 layout
        if (RespondsToSelector(new Selector("edgesForExtendedLayout")))
            EdgesForExtendedLayout = UIRectEdge.None;

        Title = "Edit Job";

        AddLabel("Start On");
        UIDatePicker startOnPicker;
        var startOnView = AddDateTimeView(out startOnPicker);

        var set = this.CreateBindingSet<EditJobView, EditJobViewModel>();
        set.Bind(startOnPicker).For("DateAndTime").To(vm => vm.TestStartOn);
        set.Bind(startOnView).To(vm => vm.TestFormatted);
        set.Apply();
    }

    private void AddLabel(string caption)
    {
        _currentTop += 10;
        var frame = new RectangleF(_leftMargin, _currentTop, 300, _labelHeight);
        var label = new UILabel(frame);
        label.Font = _labelFont;
        label.Text = caption;
        AddView(label);
        _currentTop += 2;
    }

    private UITextField AddDateTimeView(out UIDatePicker datePicker)
    {
        var textField = AddTextField();

        datePicker = new UIDatePicker();
        datePicker.Mode = UIDatePickerMode.DateAndTime;

        textField.InputView = datePicker;

        return textField;
    }

    private UITextField AddTextField()
    {
        var frame = new RectangleF(_leftMargin, _currentTop, 300, _pickerHeight);
        var textField = new UITextField(frame);
        textField.Layer.BorderColor = UIColor.Black.CGColor;
        textField.Layer.BorderWidth = 1f;
        textField.Font = _controlFont;
        textField.LeftView = _paddingInsert;
        textField.LeftViewMode = UITextFieldViewMode.Always;
        AddView(textField);
        return textField;
    }

    private void AddView(UIView view)
    {
        View.AddSubview(view);
        _currentTop += (int)view.Frame.Height;
    }
}

下面是连接它的启动代码：

protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
{
    registry.RegisterCustomBindingFactory<UIDatePicker>(
                    "DateAndTime",
                    binary => new DatePickerDateAndTimeTargetBinding(binary));
    base.FillTargetFactories(registry);
}

受保护的覆盖无效FillTargetFactorys（IMvxTargetBindingFactoryRegistry注册表）
{
registry.RegisterCustomBindingFactory(
“日期和时间”，
binary=>new DatePickerDateAndTimeTargetBinding（二进制））；
base.FillTargetFactorys（注册表）；
}

日期绑定只绑定日期-请参阅中的源代码

---

如果您想创建自己的自定义

DateAndTime

绑定，那么使用和的源代码应该很容易做到-然后您可以在安装过程中注册自定义绑定（有关如何注册自定义绑定的信息，请参阅N+1视频N=28）

谢谢Stuart。我已经基于N=28编写了一个定制的DateAndTime活页夹，并用代码更新了我的问题。调用了FireValueChange，但未调用绑定的vm属性。有什么想法吗？发现了问题-如果我从GetDate（）返回NSDate绑定不起作用。如果我返回日期时间，一切正常。

protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
{
    registry.RegisterCustomBindingFactory<UIDatePicker>(
                    "DateAndTime",
                    binary => new DatePickerDateAndTimeTargetBinding(binary));
    base.FillTargetFactories(registry);
}