添加项目文件。

common/Tnb.Common/Security/ComparisonHelper.cs

@@ -0,0 +1,71 @@
+using JNPF.DependencyInjection;
+
+namespace JNPF.Common.Security;
+
+/// <summary>
+/// 比较器辅助类，用于快速创建<see cref="IComparer{T}"/>接口的实例.
+/// </summary>
+/// <example>
+/// var comparer1 = Comparison[Person].CreateComparer(p => p.ID); var comparer2 = Comparison[Person].CreateComparer(p => p.Name); var comparer3 = Comparison[Person].CreateComparer(p => p.Birthday.Year).
+/// </example>
+/// <typeparam name="T">要比较的类型.</typeparam>
+[SuppressSniffer]
+public static class ComparisonHelper<T>
+{
+    /// <summary>
+    /// 创建指定对比委托<paramref name="keySelector"/>的实例.
+    /// </summary>
+    public static IComparer<T> CreateComparer<TV>(Func<T, TV> keySelector)
+    {
+        return new CommonComparer<TV>(keySelector);
+    }
+
+    /// <summary>
+    /// 创建指定对比委托<paramref name="keySelector"/>与结果二次比较器<paramref name="comparer"/>的实例
+    /// </summary>
+    public static IComparer<T> CreateComparer<TV>(Func<T, TV> keySelector, IComparer<TV> comparer)
+    {
+        return new CommonComparer<TV>(keySelector, comparer);
+    }
+
+    /// <summary>
+    /// 常见的比较器.
+    /// </summary>
+    /// <typeparam name="TV">要比较的类型.</typeparam>
+    private class CommonComparer<TV> : IComparer<T>
+    {
+        private readonly IComparer<TV> _comparer;
+        private readonly Func<T, TV> _keySelector;
+
+        /// <summary>
+        /// 构造函数.
+        /// </summary>
+        /// <param name="keySelector"></param>
+        /// <param name="comparer"></param>
+        public CommonComparer(Func<T, TV> keySelector, IComparer<TV> comparer)
+        {
+            _keySelector = keySelector;
+            _comparer = comparer;
+        }
+
+        /// <summary>
+        /// 构造函数.
+        /// </summary>
+        /// <param name="keySelector"></param>
+        public CommonComparer(Func<T, TV> keySelector)
+            : this(keySelector, Comparer<TV>.Default)
+        {
+        }
+
+        /// <summary>
+        /// 比较.
+        /// </summary>
+        /// <param name="x"></param>
+        /// <param name="y"></param>
+        /// <returns></returns>
+        public int Compare(T x, T y)
+        {
+            return _comparer.Compare(_keySelector(x), _keySelector(y));
+        }
+    }
+}