添加项目文件。

Sai.Toolkit.Mvvm/Attributes/MaximumAttribute.cs

@@ -0,0 +1,19 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Sai.Toolkit.Mvvm.Attributes;
+
+[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
+public sealed class MaximumAttribute : ValidationAttribute
+{
+	public MaximumAttribute(double maxValue = 0)
+	{
+		MaxValue = maxValue;
+	}
+
+	public double MaxValue { get; }
+
+	protected override ValidationResult IsValid(object value, ValidationContext validationContext)
+	{
+		return double.TryParse(value.ToString(), out var d) && d <= MaxValue ? ValidationResult.Success : new ValidationResult("输入值超出范围");
+	}
+}