Code Reference A collection of code for my reference (and perhaps other people too)

Custom Attributes

I was asked about Custom Attributes and thought it would make a good blog entry.

Custom Attributes are added to properties of a class. They give extra meaning to these properties.

Here is an example of what they look like and how they are used:

class MyClass
{
  [SearchablePropertyAttribute(DisplayType = "Primary")]
  public string FirtName
  {
      get { return firtName; }
      set { firtName= value; }
  }

  [AddressPropertyAttribute(Order = 1, ValidationRequired = true)]
  public string Address
  {
      get { return address; }
      set { address= value; }
  }
}

SearchablePropertyAttribute and AddressPropertyAttribute are both classes I created. They must extend System.Attribute.

You assign the values to these properties in the class as shown above.

They can be as simple as this:

public class SearchablePropertyAttribute : Attribute
{
    public SearchablePropertyAttribute() { }

    public string DisplayType = string.Empty;
}

public class AddressPropertyAttribute : Attribute
{
    public AddressPropertyAttribute() { }

    public int Order = 0;
    public bool ValidationRequired = false;
}

To use these attributes, you have to get the PropertyInfo of the object

...
MyClass myclass = new MyClass();

// Get a list of all the properties in the class
PropertyInfo[] piList = typeof(myclass).GetProperties();

// Loop thru each property and check if it is the
foreach (PropertyIfno pi in piList)
{
   // Get an array of the AddressPropertyAttribute attributes
   AddressPropertyAttribute[] attributes = (AddressPropertyAttribute[])pi.GetCustomAttributes(typeof(AddressPropertyAttribute), true);

   // Go thru the attributes and use them as you wish
}
...