using System; namespace Apewer { /// <summary>装箱类。</summary> public sealed class Class<T> : IDisposable // : IComparable, IComparable<T>, IComparable<Class<T>> { /// <summary>值。</summary> public T Value { get; set; } /// <summary>创建装箱实例,值为默认值。</summary> public Class() { } /// <summary>创建装箱实例,值为指定值。</summary> public Class(T value) => Value = value; #region IDisposable /// <summary>如果 <see cref="Value" /> 实现了 <see cref="IDisposable" />,则释放 <see cref="Value" /> 占用的系统资源。</summary> public void Dispose() => RuntimeUtility.Dispose(Value); #endregion #region Override /// <summary></summary> public override int GetHashCode() { if (Value != null) return Value.GetHashCode(); return base.GetHashCode(); } /// <summary></summary> public override bool Equals(object obj) { if (ReferenceEquals(this, obj)) return true; var right = obj as Class<T>; if (Value.IsNull()) { if (right == null) return true; if (right.Value.IsNull()) return true; return false; } else { if (right == null) return false; if (right.Value.IsNull()) return false; if (ReferenceEquals(Value, right.Value)) return true; return Value.Equals(right.Value); } } /// <summary></summary> public override string ToString() { if (Value == null) return null; return Value.ToString(); } #endregion #if ClassCompare #region Compare /// <summary></summary> /// <exception cref="NotSupportedException"></exception> public int CompareTo(object obj) { if (typeof(IComparable).IsAssignableFrom(typeof(T))) { var comparable = Value as IComparable; if (comparable.IsNull()) { if (obj is Class<T> bro) { if (bro == null) return 0; if (bro.Value.IsNull()) return 0; return -1; } if (obj.IsNull()) return 0; return -1; } else { if (obj != null && obj is Class<T> bro) return comparable.CompareTo(bro.Value); return comparable.CompareTo(obj); } } throw new NotImplementedException($"类型 {typeof(T).Name} 没有实现 {nameof(IComparable)} 接口。"); } /// <summary></summary> /// <exception cref="MissingMemberException"></exception> /// <exception cref="NotSupportedException"></exception> public int CompareTo(T other) { if (Value == null) throw new MissingMemberException(typeof(T).FullName, nameof(Value)); if (!(Value is IComparable)) throw new NotSupportedException(); return ((IComparable<T>)Value).CompareTo(other); } /// <summary></summary> /// <exception cref="MissingMemberException"></exception> /// <exception cref="NotSupportedException"></exception> public int CompareTo(Class<T> other) { if (Value == null) throw new MissingMemberException(typeof(T).FullName, nameof(Value)); if (Value is IComparable) return ((IComparable)Value).CompareTo(other.Value); if (Value is IComparable<T>) return ((IComparable<T>)Value).CompareTo(other.Value); throw new NotSupportedException(); } #endregion #endif #region 运算符。 /// <summary>从 <see cref="Class{T}"/> 到 Boolean 的隐式转换,判断 <see cref="Class{T}"/> 包含值。</summary> /// <remarks>当 T 是 Boolean 时,获取 Value。<br />当 T 是 String 时,判断 Value 不为 NULL 且不为空。</remarks> public static implicit operator bool(Class<T> instance) { if (instance == null) return false; // var boolean = instance as Class<bool>; // if (boolean != null) return boolean.Value; // var text = instance as Class<string>; // if (text != null) return !string.IsNullOrEmpty(text.Value); return true; } // /// <summary>从 <see cref="Class{T}"/> 到 T 的隐式转换。</summary> // public static implicit operator T(Class<T> instance) // { // if (instance == null) return default(T); // if (typeof(T).Equals(typeof(bool))) return instance.Value; // return instance.Value; // } // /// <summary>从 T 到 <see cref="Class{T}"/> 的隐式转换。</summary> // public static implicit operator Class<T>(T value) => new Class<T>(value); #endregion } }