C#特性属性验证

记得以前的 if(model.Validate()){...}

1.abstract继承类

public abstract class ValidateAttribute:Attribute
{
    public abstract bool Validate(object age);
}

2.继承实现类（可以用来验证属性和字段的）

public static class AttributeExtends
    {
        public static bool Validate<T>(this T t) where T : class
        {
            Type type = t.GetType();
            //循环属性
            foreach (var prop in type.GetProperties())
            {
                if (prop.IsDefined(typeof(ValidateAttribute), true))
                {
                    object ovalue = prop.GetValue(t);
                    foreach (ValidateAttribute attribute in prop.GetCustomAttributes(typeof(ValidateAttribute), true))
                    {
                        if (!attribute.Validate(ovalue))
                        {
                            return false;
                        }
                    }
                }
            }
            //循环字段
            foreach (var field in type.GetFields())
            {
                if (field.IsDefined(typeof(ValidateAttribute), true))
                {
                    object ovalue = field.GetValue(t);
                    foreach (ValidateAttribute attribute in field.GetCustomAttributes(typeof(ValidateAttribute), true))
                    {
                        if (!attribute.Validate(ovalue))
                        {
                            return false;
                        }
                    }
                }
            }
            return true;
        }
    }

3.验证类（验证值需要大于_minAge）

public class StudentAttribute: ValidateAttribute
{
    public int _minAge;
    public StudentAttribute(int minAge)
    {
        _minAge = minAge;
    }

    public override bool Validate(object oValue)
    {
        return oValue != null && int.TryParse(oValue.ToString(), out int lValue) && lValue > _minAge;
    }
}

4.类上特性的应用

public class Student
{
     public int ID { get; set; }
     public string Name { get; set; }
     public string Sex { get; set; }
     [StudentAttribute(minAge:18)]
     public int Age { get; set; }
}

5.使用

static void Main(string[] args)
{
    try
    {
         Console.WriteLine("Start");
         Student student = new Student 
         { 
             ID = 1,
             Sex ="男",
             Name = "dzw",
             Age = 12
         };
         Console.WriteLine(student.Validate());
    }
    catch (Exception ex)
    {
         Console.WriteLine(ex.Message);
    }
    Console.ReadLine();
}