Question

有没有办法在类中“标记”一个属性，这样当我遍历类的属性时，我可以执行一个方法，基于标记或未标记的属性。

我无法通过检查属性值来执行此操作。

测试类循环

public class SomeClass {
public List<Object> PropertyOne { get; set; }
public List<Object> PropertyTwo { get; set; }

public SomeClass() {
PropertyOne = new List<Object>();
PropertyTwo = new List<Object>();
}
}

阅读属性：

SomeClass myObject = new SomeClass();
Type myType = myObject.GetType();
IList<PropertyInfo> props = new List<PropertyInfo>(myType.GetProperties());

foreach (PropertyInfo prop in props)
{
    // If this prop is "marked" -> Execute code below
}

编辑：谢谢你们两位大家的答案。

Answer 1

这就是属性的用途。 Create your own attribute，将其应用于属性并测试prop.GetCustomAttribute<MyMarkerAttribute>()不为空。

public class MyMarkerAttribute : Attribute 
{

}

public class SomeClass 
{
    // unmarked
    public List<Object> PropertyOne { get; set; }

    [MyMarkerAttribute] // marked
    public List<Object> PropertyTwo { get; set; }
}

foreach (PropertyInfo prop in props)
{
    if (prop.GetCustomAttribute<MyMarkerAttribute>() != null)
    {
        // ...
    }
}

Answer 2

您可以使用属性

public class MyAttribute : Attribute
{

}

public class SomeClass {
[MyAttribute]
public List<Object> PropertyOne { get; set; }
public List<Object> PropertyTwo { get; set; }

public SomeClass() {
PropertyOne = new List<Object>();
PropertyTwo = new List<Object>();
}
}

然后在迭代属性时检查属性，如下所述：How to retrieve Data Annotations from code? (programmatically)

public static T GetAttributeFrom<T>(this object instance, string propertyName) where T : Attribute
{
    var attrType = typeof(T);
    var property = instance.GetType().GetProperty(propertyName);
    return (T)property .GetCustomAttributes(attrType, false).FirstOrDefault();
}

标记GetProperties的属性

2 个答案: