CODEWITHSUNDEEP
c#reflectionnunitcustom-attributes
132u
132u

Reputation: 21

Extracting attribute parameter values

I can retrieve all of the test names out of an NUnit test class library assembly, but I need to retrieve their category names as well from the parameter passed to the Category attribute.

For example: 

[Category("text")] 
public void test() {}

I need to get "text" from the DLL.

Upvotes: 2

Views: 190

Answers (1)

jlvaquero
jlvaquero

Reputation: 8785

Using reflection.

For example:

Given this attribute applied to fields:

<AttributeUsage(AttributeTargets.Field)> _
     Public NotInheritable Class DataBaseValueAttribute
    Inherits Attribute

    Private _value As Object

    Public Sub New(ByVal value As Object)
      _value = value
    End Sub

    Public Function GetValue() As Object
      Return _value
    End Function
  End Class

You can use reflection to get field info from a type and get the attributes:

Dim tipo As Type = GetType(YourType)
Dim fi As FieldInfo = tipo.GetField("fieldName")

Dim attribs As Atributos.DataBaseValueAttribute() = CType(fi.GetCustomAttributes(GetType(Atributos.DataBaseValueAttribute), False), Atributos.DataBaseValueAttribute())
If attribs.Count > 0 Then
   Return attribs(0).GetValue()
Else
   Return Nothing
End If

In c#:

[AttributeUsage(AttributeTargets.Field)]
public sealed class DataBaseValueAttribute : Attribute
{
    private object _value;
    public DataBaseValueAttribute(object value)
    {
        _value = value;
    }

    public object GetValue()
    {
        return _value;
    }
}

Type tipo = typeof(YourType);
FieldInfo fi = tipo.GetField("fieldName");

Atributos.DataBaseValueAttribute[] attribs = (Atributos.DataBaseValueAttribute[])fi.GetCustomAttributes(typeof(Atributos.DataBaseValueAttribute), false);
if (attribs.Count > 0) {
    return attribs(0).GetValue();
} else {
    return null;
}

Upvotes: 1

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