diff --git a/Apewer/CollectionUtility.cs b/Apewer/CollectionUtility.cs
index b074722..e809a2e 100644
--- a/Apewer/CollectionUtility.cs
+++ b/Apewer/CollectionUtility.cs
@@ -127,6 +127,12 @@ namespace Apewer
             }
         }
 
+        /// <summary>检查当前元素是否存在于集合。</summary>
+        public static bool In<T>(this T item, IEnumerable<T> collection) => Contains(collection, item);
+
+        /// <summary>检查当前元素是否存在于集合。</summary>
+        public static bool In<T>(this T item, params T[] collection) => Contains(collection, item);
+
         #endregion
 
         #region 类型转换