.Net DefaultValueAttribute on Properties

Question

I got this code in a user control:

[DefaultValue(typeof(Color), \"Red\")]
public Color MyColor { get; set; }

How can I change MyColor

Answer 1

DefaultValueAttribute is not used by the compiler, and (perhaps confusingly) it doesn't set the initial value. You need to do this your self in the constructor. Places that do use DefaultValueAttribute include:

• PropertyDescriptor - provides ShouldSerializeValue (used by PropertyGrid etc)
• XmlSerializer / DataContractSerializer / etc (serialization frameworks) - for deciding whether it needs to be included

Instead, add a constructor:

public MyType() {
  MyColor = Color.Red;
}

(if it is a struct with a custom constructor, you need to call :base() first)