尝试实现 DecimalAboveThresholdAttribute 有问题
我正在尝试实现类似于 IntegerAboveThresholdAttribute 的东西，只不过它应该使用小数。
这是我将其用作 BusinessException 的实现，
[DecimalAboveThreshold(typeof(BusinessException), 10000m, ErrorMessage = "Dollar Value must be 10000 or lower.")]
但是，我收到一条错误，指出属性必须是属性参数类型的常量表达式、typeof 表达式或数组创建表达式。我想知道是否可以解决这个问题，如果不能，是否可以做类似的事情？
这是 DecimalAboveThresholdAttribute 的源代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CoreLib.Messaging;
namespace (*removed*)
{
public class DecimalBelowThresholdAttribute : BusinessValidationAttribute
{
private decimal _Threshold;
public DecimalBelowThresholdAttribute(Type exceptionToThrow, decimal threshold)
: base(exceptionToThrow)
{
_Threshold = threshold;
}
protected override bool Validates(decimal value)
{
return (decimal)value < _Threshold;
}
}
}
我也想知道是否也可以使用 DateTimes 来做到这一点。
I am trying to implement something similar to IntegerAboveThresholdAttribute except that it should work with decimals.
This is my implementation of me using it as a BusinessException
[DecimalAboveThreshold(typeof(BusinessException), 10000m, ErrorMessage = "Dollar Value must be 10000 or lower.")]
However, I receive an error saying An attribute must be a constant expression, typeof expression, or array creation expression of an attribute parameter type. I was wondering if it is possible to fix this, and if not, is it possible to do something similar?
Here is the source code for DecimalAboveThresholdAttribute:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CoreLib.Messaging;
namespace (*removed*)
{
public class DecimalBelowThresholdAttribute : BusinessValidationAttribute
{
private decimal _Threshold;
public DecimalBelowThresholdAttribute(Type exceptionToThrow, decimal threshold)
: base(exceptionToThrow)
{
_Threshold = threshold;
}
protected override bool Validates(decimal value)
{
return (decimal)value < _Threshold;
}
}
}
I also would like to know if I can do this with DateTimes as well.
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不允许使用小数作为属性参数。这是 .NET 属性中的内置限制。您可以在 MSDN。所以它不适用于十进制和日期时间。作为一种解决方法（尽管它不是类型安全的），您可以使用字符串：
用法：
You are not allowed to use decimals as attribute parameters. This is a built in restriction in .NET attributes. You can find the available parameter types on MSDN. So it won't work with decimal and DateTime. As a workaround (although it won't be typesafe) you can use strings:
Usage: