查看是否将属性应用于类属性内字符串类型的属性

Question

say I have the attribute:

public class Column_Attribute : Attribute
{
    public string DbType { get; set; }
    public bool IsPrimaryKey { get; set; }
}

then I can apply that attribute to a property as:

 [Column_Attribute(DbType = "Integer", IsPrimaryKey = true)]
 public int Id { get; set; }   

Now how can I get information about the property Id from the attribute class. In other words I want to do something like:

public class Column_Attribute : Attribute
{
    // constructor
    public Column_Attribute(){
      // if the property has the name Id do something...
      // OR
      // if this is an attribute of a property do something
      // if this is an attribute of a field do something else

      // If this attribute is targeting a property that is a string do something
    }

    public string DbType { get; set; }
    public bool IsPrimaryKey { get; set; }
}

I actually need to know if the attribute is being applied to a property that is a string.

I know how to do that with reflection but I want to do that inside the attribute class. Is that possible. Hope I am explaining myself correctly

Answer 1

You cannot do that without reflection because the code in the constructor will not be executed until you call GetCustomAttributes() , which is a part of reflection.

see http://msdn.microsoft.com/en-us/library/z919e8tw(v=vs.80).aspx

Calling GetCustomAttributes on SampleClass causes an Author object to be constructed and initialized as above

If you want your attribute class to contain the processing code, you could create a method receiving the property name. The property name will be available at the time of calling GetCustomAttributes().