KJD/AllBase/BindableBase.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq.Expressions;
using System.Reflection;
using System.Runtime.CompilerServices;

namespace AllBase
{
	/// <summary>
	/// 提供属性更改通知功能的基类
	/// </summary>
	public abstract class BindableBase : INotifyPropertyChanged
	{
		public event PropertyChangedEventHandler? PropertyChanged;

		private Dictionary<string, object?>? _propertyBag;

		#region PropertyBag Accessor

		private Dictionary<string, object?> PropertyBag => _propertyBag ??= [];

		#endregion

		#region Constructor & Initialization

		public BindableBase()
		{
			OnInitialized();
		}

		public virtual void OnInitialized()
		{
		}

		#endregion

		#region Property Name Extraction

		public static string GetPropertyName<T>(Expression<Func<T>> expression)
		{
			return GetPropertyNameFast(expression);
		}

		internal static string GetPropertyNameFast(LambdaExpression expression)
		{
			if (expression.Body is not MemberExpression memberExpression)
			{
				throw new ArgumentException("MemberExpression is expected in expression.Body", nameof(expression));
			}

			MemberInfo member = memberExpression.Member;
			if (member.MemberType == MemberTypes.Field && member.Name != null && member.Name.StartsWith("$VB$Local_"))
			{
				return member.Name.Substring("$VB$Local_".Length);
			}

			string result = member.Name
				?? throw new ArgumentNullException(nameof(member.Name), "member.Name is null");
			return result;
		}

		#endregion

		#region Property Access (Expression-based)

		protected T? GetProperty<T>(Expression<Func<T>> expression)
		{
			return GetPropertyCore<T>(GetPropertyName(expression));
		}

		protected bool SetProperty<T>(Expression<Func<T>> expression, T value)
		{
			return SetProperty(expression, value, (Action?)null);
		}

		protected bool SetProperty<T>(Expression<Func<T>> expression, T value, Action? changedCallback)
		{
			string propertyName = GetPropertyName(expression);
			return SetPropertyCore(propertyName, value, changedCallback);
		}

		protected bool SetProperty<T>(Expression<Func<T>> expression, T value, Action<T?>? changedCallback)
		{
			string propertyName = GetPropertyName(expression);
			return SetPropertyCore(propertyName, value, changedCallback);
		}

		protected bool SetProperty<T>(ref T storage, T value, Expression<Func<T>> expression)
		{
			return SetProperty(ref storage, value, expression, null);
		}

		protected bool SetProperty<T>(ref T storage, T value, Expression<Func<T>> expression, Action? changedCallback)
		{
			return SetProperty(ref storage, value, GetPropertyName(expression), changedCallback);
		}

		protected void RaisePropertyChanged<T>(Expression<Func<T>> expression)
		{
			RaisePropertyChanged(GetPropertyName(expression));
		}

		#endregion

		#region Property Access (CallerMemberName-based)

		protected T? GetValue<T>([CallerMemberName] string? propertyName = null)
		{
			GuardPropertyName(propertyName);
			return GetPropertyCore<T>(propertyName);
		}

		protected bool SetValue<T>(T value, [CallerMemberName] string? propertyName = null)
		{
			return SetValue(value, (Action?)null, propertyName);
		}

		protected bool SetValue<T>(T value, Action? changedCallback, [CallerMemberName] string? propertyName = null)
		{
			return SetPropertyCore(propertyName!, value, changedCallback);
		}

		protected bool SetValue<T>(T value, Action<T?>? changedCallback, [CallerMemberName] string? propertyName = null)
		{
			return SetPropertyCore(propertyName!, value, changedCallback);
		}

		protected bool SetValue<T>(ref T storage, T value, [CallerMemberName] string? propertyName = null)
		{
			return SetValue(ref storage, value, null, propertyName);
		}

		protected bool SetValue<T>(ref T storage, T value, Action? changedCallback, [CallerMemberName] string? propertyName = null)
		{
			GuardPropertyName(propertyName);
			return SetProperty(ref storage, value, propertyName, changedCallback);
		}

		#endregion

		#region Property Access (String-based)

		protected bool SetProperty<T>(ref T storage, T value, string propertyName)
		{
			return SetProperty(ref storage, value, propertyName, null);
		}

		protected virtual bool SetProperty<T>(ref T storage, T value, string propertyName, Action? changedCallback)
		{
			VerifyAccess();
			if (CompareValues(storage, value, propertyName))
			{
				return false;
			}

			storage = value;
			RaisePropertyChanged(propertyName);
			changedCallback?.Invoke();
			return true;
		}

		#endregion

		#region PropertyBag Core Access

		private T? GetPropertyCore<T>(string propertyName)
		{
			if (PropertyBag.TryGetValue(propertyName, out object? value))
			{
				return (T?)value;
			}

			return default;
		}

		protected virtual bool SetPropertyCore<T>(string propertyName, T value, out T? oldValue)
		{
			VerifyAccess();
			oldValue = default;
			if (PropertyBag.TryGetValue(propertyName, out object? value2))
			{
				oldValue = (T?)value2;
			}

			if (CompareValues(oldValue, value, propertyName))
			{
				return false;
			}

			lock (PropertyBag)
			{
				PropertyBag[propertyName] = value;
			}

			RaisePropertyChanged(propertyName);
			return true;
		}

		private bool SetPropertyCore<T>(string propertyName, T value, Action? changedCallback)
		{
			bool flag = SetPropertyCore(propertyName, value, out T? oldValue);
			if (flag)
			{
				changedCallback?.Invoke();
			}

			return flag;
		}

		private bool SetPropertyCore<T>(string propertyName, T value, Action<T?>? changedCallback)
		{
			bool flag = SetPropertyCore(propertyName, value, out T? oldValue);
			if (flag)
			{
				changedCallback?.Invoke(oldValue);
			}

			return flag;
		}

		#endregion

		#region PropertyChanged Notification

		protected virtual void RaisePropertyChanged(string propertyName)
		{
			PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
		}

		protected void RaisePropertyChanged()
		{
			RaisePropertiesChanged(null);
		}

		protected void RaisePropertiesChanged(params string[]? propertyNames)
		{
			if (propertyNames == null || propertyNames.Length == 0)
			{
				RaisePropertyChanged(string.Empty);
				return;
			}

			foreach (string propertyName in propertyNames)
			{
				RaisePropertyChanged(propertyName);
			}
		}

		#endregion

		#region Validation & Utility

#pragma warning disable CS8777
		private static void GuardPropertyName(string? propertyName)
		{
			if (string.IsNullOrEmpty(propertyName))
			{
				throw new ArgumentNullException(nameof(propertyName));
			}
		}
#pragma warning restore CS8777

		protected virtual void VerifyAccess()
		{
		}

		protected virtual bool CompareValues<T>(T storage, T value, string propertyName)
		{
			return EqualityComparer<T>.Default.Equals(storage, value);
		}

		#endregion
	}
}