添加项目文件。

ConsoleApp/Program.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using CommunityToolkit.Diagnostics;
+
+namespace ConsoleApp
+{
+    internal class Program
+    {
+        static void Main(string[] args)
+        {
+            string str = "";
+            double a = 10.0;
+            double b = 100;
+            //确保str满足条件才能继续执行，不满足即抛出异常
+            Guard.IsNotNullOrEmpty(str);//抛出异常
+            Guard.IsLessThan(a,b);
+        }
+    }
+}