添加项目文件。

Szmedi.RvKits/Attributes/IsNumericAttribute.cs

@@ -0,0 +1,15 @@
+using System;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+
+namespace Szmedi.RvKits.Attributes
+{
+    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
+    public sealed class IsNumericAttribute : ValidationAttribute
+    {
+        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+        {
+            return double.TryParse(value.ToString(), out double _) ? ValidationResult.Success : new("输入内容不是数值。");
+        }
+    }
+}