如何使用反射查找数据注释属性及其参数

Question

我有一些像这样的数据注释属性：

[StringLength(20, MinimumLength = 5, ErrorMessage = "First name must be between 5 and 20 characters")]

How I can Find Data AnnotationAttributes and TheirParameters using Reflection?

谢谢

Answer 1

我假设你有这样的东西：

[StringLength(20, MinimumLength = 5, ErrorMessage = "First name must be between 5 and 20 characters")]
public string FirstName {get;set;}

要从中获取属性和属性：

StringLengthAttribute strLenAttr = 
  typeof(Person).GetProperty("FirstName").GetCustomAttributes(
  typeof(StringLengthAttribute), false).Cast<StringLengthAttribute>().Single();


int maxLen = strLenAttribute.MaximumLength;