1

Src/Core/Extensions/Func.cs

@@ -1,24 +1,38 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 
 namespace BITKit
 {
-	public static class FuncExtensions
-	{
-		public static IEnumerable<Func<T0,T1>> CastAsFunc<T0,T1>(this Func<T0,T1> self)
-		{
-			return self.GetInvocationList().Cast<Func<T0, T1>>();
-		}
-		public static IEnumerable<Func<T0,T1,T2>> CastAsFunc<T0,T1,T2>(this Func<T0,T1,T2> self)
-		{
-			return self.GetInvocationList().Cast<Func<T0, T1,T2>>();
-		}
-		public static IEnumerable<Func<T0,T1,T2,T3>> CastAsFunc<T0,T1,T2,T3>(this Func<T0,T1,T2,T3> self)
-		{
-			return self.GetInvocationList().Cast<Func<T0, T1,T2,T3>>();
-		}
-	}
+    public static class FuncExtensions
+    {
+        public static IEnumerable<Func<T0, T1>> CastAsFunc<T0, T1>(this Func<T0, T1> self)
+        {
+            return self is null ? Array.Empty<Func<T0,T1>>() : self?.GetInvocationList().Cast<Func<T0, T1>>();
+        }
 
+        public static IEnumerable<Func<T0, T1, T2>> CastAsFunc<T0, T1, T2>(this Func<T0, T1, T2> self)
+        {
+            if (self is null)
+            {
+                yield break;
+            }
+
+            Delegate[] invocationList = self.GetInvocationList();
+
+            // 遍历委托数组，将每个委托转换为 Func<T0, T1, T2> 并返回
+            foreach (var delegateItem in invocationList)
+            {
+                if (delegateItem is not null && delegateItem is Func<T0, T1, T2> func)
+                {
+                    yield return func;
+                }
+            }
+        }
+
+        public static IEnumerable<Func<T0, T1, T2, T3>> CastAsFunc<T0, T1, T2, T3>(this Func<T0, T1, T2, T3> self)
+        {
+            return self?.GetInvocationList().Cast<Func<T0, T1, T2, T3>>();
+        }
+    }
 }