Xaml 表单绑定到绑定属性或其他东西

我有一页

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:controls="clr-namespace:PassSystem.Controls;assembly=PassSystem"
             x:Class="PassSystem.Views.CreatePassPage"
             Title="Оформление пропуска">
    <ScrollView HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
        <StackLayout>
            <FlexLayout Direction="Column" BackgroundColor="White">
                <controls:ActionOption Title="Название" Value="1" LeftMargin="18">
                </controls:ActionOption>
            </FlexLayout>
        </StackLayout>
    </ScrollView>
</ContentPage>

补充资料。点击效果

{
        public ClickableEffect() : base("PassSystem.ClickableEffect")
        {
        }

        #region Click

        public static readonly BindableProperty ClickCommandProperty = BindableProperty
            .CreateAttached("ClickCommand", typeof(ICommand), typeof(ClickableEffect), (object)null);

        public static ICommand GetClickCommand(BindableObject view)
        {
            return (ICommand)view.GetValue(ClickCommandProperty);
        }

        public static void SetClickCommand(BindableObject view, ICommand value)
        {
            view.SetValue(ClickCommandProperty, value);
        }


        public static readonly BindableProperty ClickCommandParameterProperty = BindableProperty
            .CreateAttached("ClickCommandParameter", typeof(object), typeof(ClickableEffect), (object)null);

        public static object GetClickCommandParameter(BindableObject view)
        {
            return view.GetValue(ClickCommandParameterProperty);
        }

        public static void SetClickCommandParameter(BindableObject view, object value)
        {
            view.SetValue(ClickCommandParameterProperty, value);
        }

        #endregion
}

Android上可点击效果的实现：

public class ClickableListener : Java.Lang.Object, View.IOnTouchListener, View.IOnClickListener, View.IOnLongClickListener
    {
        private Element Element { get; }
        private View View { get; }

        public ClickableListener(Element element, View view)
        {
            Element = element;
            View = view;
        }

        ...

        public void OnClick(View v)
        {
            Tap();
        }

        private void Tap()
        {
            var command = ClickableEffect.GetClickCommand(Element);
            var parameter = ClickableEffect.GetClickCommandParameter(Element);
            command?.Execute(parameter);
        }
    }

[assembly: ResolutionGroupName("PassSystem")]
[assembly: ExportEffect(typeof(AndroidClickableEffect), "ClickableEffect")]
namespace PassSystem.Droid.Native.Effects
{
    public class AndroidClickableEffect : PlatformEffect
    {
        private bool _attached;

        protected override void OnAttached()
        {
            //because an effect can be detached immediately after attached (happens in listview), only attach the handler one time.
            if(!_attached)
            {
                var control = Control ?? Container;

                var listener = new ClickableListener(Element, control);
                control.SetOnClickListener(listener);
                ...
                _attached = true;
            }
        }
}

如何实现这一点？非常感谢。

---

另外，我很难解释，希望你能理解。：）

为了达到预期的行为：

ClickCommand

必须是

ClickableEffect

的附加属性。更多信息可在官方文件中找到：

由于在效果和页面之间有一个

ContentView

，因此必须确保

ContentView

的

BindindContext

设置正确。恐怕您必须在

ContentView

级别上定义

ClickCommand

bindable属性，并将其绑定到效果的命令。所以：

Page.BindingContext.ClickCommand

=>

ContentView.ClickCommand

=>

ClickableEffect.ClickCommand

（其中=>是绑定）

---

这基本上提出了一个问题——为什么需要效果？

1。是的，我有。2.我试图实现它。在ViewModel的页面上，我创建了一个ICommand“ClickCommand”，在ContentView中也创建了“ClickCommand”。但这对我不起作用。很可能是我错误地连接了数据。因为通过ContentView->СlickbleEffect的绑定，它可以工作。我需要这种效果来识别手势。很可能您没有将ContentView的BindingContext设置为self。不，我编写了BindingContext=this。不要在ContentView级别执行此操作，而是在使用此效果的按钮上执行此操作。可以更详细吗？ContentView本身就是我的按钮。

<controls:ActionOption Title="TitleHere" Value="1" LeftMargin="18" Clicked="{Binding ClickedCommand}">
</controls:ActionOption>

`effects:ClickableEffect.ClickCommand="{Binding ClickCommand (FromPage)}"`

{
        public ClickableEffect() : base("PassSystem.ClickableEffect")
        {
        }

        #region Click

        public static readonly BindableProperty ClickCommandProperty = BindableProperty
            .CreateAttached("ClickCommand", typeof(ICommand), typeof(ClickableEffect), (object)null);

        public static ICommand GetClickCommand(BindableObject view)
        {
            return (ICommand)view.GetValue(ClickCommandProperty);
        }

        public static void SetClickCommand(BindableObject view, ICommand value)
        {
            view.SetValue(ClickCommandProperty, value);
        }


        public static readonly BindableProperty ClickCommandParameterProperty = BindableProperty
            .CreateAttached("ClickCommandParameter", typeof(object), typeof(ClickableEffect), (object)null);

        public static object GetClickCommandParameter(BindableObject view)
        {
            return view.GetValue(ClickCommandParameterProperty);
        }

        public static void SetClickCommandParameter(BindableObject view, object value)
        {
            view.SetValue(ClickCommandParameterProperty, value);
        }

        #endregion
}

public class ClickableListener : Java.Lang.Object, View.IOnTouchListener, View.IOnClickListener, View.IOnLongClickListener
    {
        private Element Element { get; }
        private View View { get; }

        public ClickableListener(Element element, View view)
        {
            Element = element;
            View = view;
        }

        ...

        public void OnClick(View v)
        {
            Tap();
        }

        private void Tap()
        {
            var command = ClickableEffect.GetClickCommand(Element);
            var parameter = ClickableEffect.GetClickCommandParameter(Element);
            command?.Execute(parameter);
        }
    }

[assembly: ResolutionGroupName("PassSystem")]
[assembly: ExportEffect(typeof(AndroidClickableEffect), "ClickableEffect")]
namespace PassSystem.Droid.Native.Effects
{
    public class AndroidClickableEffect : PlatformEffect
    {
        private bool _attached;

        protected override void OnAttached()
        {
            //because an effect can be detached immediately after attached (happens in listview), only attach the handler one time.
            if(!_attached)
            {
                var control = Control ?? Container;

                var listener = new ClickableListener(Element, control);
                control.SetOnClickListener(listener);
                ...
                _attached = true;
            }
        }
}