Update

Author: jerviscui

src/Tests/StructTest/Program.cs

@@ -7,25 +7,29 @@ internal class Program
 
     private static void Main(string[] args)
     {
-        var m1 = new Measurement();
-        Console.WriteLine(m1);  // output: NaN (Undefined)
+        //var m1 = new Measurement();
+        //Console.WriteLine(m1);  // output: NaN (Undefined)
 
-        var m2 = default(Measurement);
-        Console.WriteLine(m2);  // output: 0 ()
+        //var m2 = default(Measurement);
+        //Console.WriteLine(m2);  // output: 0 ()
 
-        var ms = new Measurement[2];
-        Console.WriteLine(string.Join(", ", ms));  // output: 0 (), 0 ()
+        //var ms = new Measurement[2];
+        //Console.WriteLine(string.Join(", ", ms));  // output: 0 (), 0 ()
 
-        ValueTypeTest.ShowSize();
+        //ValueTypeTest.ShowSize();
 
-        ValueTypeTest.OutOfPrecisionTrueTest();
-        ValueTypeTest.OutOfPrecisionFalseTest();
+        //ValueTypeTest.OutOfPrecisionTrueTest();
+        //ValueTypeTest.OutOfPrecisionFalseTest();
 
-        Console.WriteLine();
-        ValueTypeTest.EffectiveLength_4();
+        //Console.WriteLine();
+        //ValueTypeTest.EffectiveLength_4();
+
+        //Console.WriteLine();
+        //ValueTypeTest.RoundAlgorithm();
 
+        ValidationTest.ValidationError();
         Console.WriteLine();
-        ValueTypeTest.RoundAlgorithm();
+        ValidationTest.ValidationAllow();
     }
 
     #endregion

src/Tests/StructTest/ValidationTest.cs

@@ -0,0 +1,79 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace StructTest;
+
+public static class ValidationTest
+{
+
+    #region Constants & Statics
+
+    public static void ValidationAllow()
+    {
+        var product = new Product
+        {
+            Price = 100_000.00m,
+            Price2 = 0.01m,
+            Price3 = 1000000000000000, // no error, is wrong!
+            Price4 = 999_999_999_999_999.99981m //  no error
+        };
+        var context = new ValidationContext(product);
+        var results = new List<ValidationResult>();
+
+        var isValid = Validator.TryValidateObject(product, context, results, true);
+
+        if (!isValid)
+        {
+            foreach (var error in results)
+            {
+                Console.WriteLine($"{string.Join(',', error.MemberNames)} : {error.ErrorMessage}");
+            }
+        }
+    }
+
+    public static void ValidationError()
+    {
+        var product = new Product
+        {
+            Price = -1.00m,
+            Price2 = 0.001m,
+            Price3 = 999_999_999_999_999.99991m, // no error, is wrong!
+            Price4 = 999_999_999_999_999.99991m // error
+        };
+        var context = new ValidationContext(product);
+        var results = new List<ValidationResult>();
+
+        var isValid = Validator.TryValidateObject(product, context, results, true);
+
+        if (!isValid)
+        {
+            foreach (var error in results)
+            {
+                Console.WriteLine($"{string.Join(',', error.MemberNames)} : {error.ErrorMessage}");
+            }
+        }
+    }
+
+    #endregion
+
+    public class Product
+    {
+
+        #region Properties
+
+        [Range(0.01, 100_000.00, ErrorMessage = "价格必须在0.01到100,000.00之间")]
+        public decimal Price { get; set; }
+
+        [Range(typeof(decimal), "0.01", "100000.00")]
+        [DataType(DataType.Currency)]
+        [DisplayFormat(DataFormatString = "{0:C2}")]
+        public decimal Price2 { get; set; }
+
+        [Range(0.0001, 999_999_999_999_999.9999)] // 超过 double 有效位数，between 0.0001 and 1000000000000000
+        public decimal Price3 { get; set; }
+
+        [Range(typeof(decimal), "0.0001", "999999999999999.9999")]
+        public decimal Price4 { get; set; }
+
+        #endregion
+    }
+}

src/Tests/StructTest/ValueTypeTest.cs

@@ -1,6 +1,6 @@
 namespace StructTest;
 
-public class ValueTypeTest
+public static class ValueTypeTest
 {
 
     #region Constants & Statics