Files
GreadyPoang/GreadyPoang.Common/Specifics/EventToCommandBehavior.cs

51 lines
1.6 KiB
C#

using System.Reflection;
using System.Windows.Input;
namespace GreadyPoang.Common;
public class EventToCommandBehavior : BehaviorBase<VisualElement>
{
public string EventName { get; set; }
public static readonly BindableProperty CommandProperty =
BindableProperty.Create(nameof(Command), typeof(ICommand), typeof(EventToCommandBehavior));
public ICommand Command
{
get => (ICommand)GetValue(CommandProperty);
set => SetValue(CommandProperty, value);
}
private EventInfo eventInfo;
private Delegate eventHandler;
protected override void OnAttachedTo(VisualElement bindable)
{
base.OnAttachedTo(bindable);
if (bindable == null || string.IsNullOrEmpty(EventName))
return;
eventInfo = bindable.GetType().GetRuntimeEvent(EventName);
if (eventInfo == null)
throw new ArgumentException($"Event '{EventName}' not found on type '{bindable.GetType().Name}'");
MethodInfo methodInfo = typeof(EventToCommandBehavior).GetTypeInfo().GetDeclaredMethod(nameof(OnEvent));
eventHandler = methodInfo.CreateDelegate(eventInfo.EventHandlerType, this);
eventInfo.AddEventHandler(bindable, eventHandler);
}
protected override void OnDetachingFrom(VisualElement bindable)
{
base.OnDetachingFrom(bindable);
if (eventInfo != null && eventHandler != null)
eventInfo.RemoveEventHandler(bindable, eventHandler);
}
private void OnEvent(object sender, object eventArgs)
{
if (Command?.CanExecute(eventArgs) == true)
Command.Execute(eventArgs);
}
}