ClockUtility：增加 string.DateTime 扩展方法

Apewer/ClockUtility.cs

@@ -51,6 +51,15 @@ namespace Apewer
             return failed;
         }
 
+        /// <summary>解析文本，获取 <see cref="System.DateTime"/> 实例。</summary>
+        public static Class<DateTime> DateTime(this string text) => Parse(text);
+
+        /// <summary>解析文本，获取 <see cref="System.DateTime"/> 实例。</summary>
+        public static DateTime DateTime(this string text, Func<DateTime> failed) => Parse(text, failed);
+
+        /// <summary>解析文本，获取 <see cref="System.DateTime"/> 实例。</summary>
+        public static DateTime DateTime(this string text, DateTime failed) => Parse(text, failed);
+
         #endregion
 
         #region Fixed