ParameterInfo.GetCustomAttributes Method (Boolean)

Parameters

• inherit
  Type: System.Boolean
  This parameter is ignored for objects of this type. See Remarks.

Return Value

Type: array<System.Object[]
An array that contains all the custom attributes applied to this parameter.

Imports System.Reflection

' Define a custom attribute with one named parameter.
<AttributeUsage(AttributeTargets.Parameter)> Public Class MyAttribute
   Inherits Attribute
   Private myName As String

   Public Sub New(ByVal name As String)
      myName = name
   End Sub

   Public ReadOnly Property Name() As String
      Get
         Return myName
      End Get
   End Property
End Class

' Define a class which has a custom attribute associated with one of 
' the parameters of a method. 
Public Class MyClass1

   Public Sub MyMethod( _
           <MyAttribute("This is an example parameter attribute")> _
           ByVal i As Integer _
       )
      Return
   End Sub
End Class


Public Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      ' Get the type of the class 'MyClass1'.
      Dim myType As Type = GetType(MyClass1)
      ' Get the members associated with the class 'MyClass1'.
      Dim myMethods As MethodInfo() = myType.GetMethods()

      ' Display the attributes for each of the parameters of each method of the class 'MyClass1'.
      For i As Integer = 0 To myMethods.Length - 1
         ' Get the parameters for the method.
         Dim myParameters As ParameterInfo() = myMethods(i).GetParameters()

         If myParameters.Length > 0 Then
            outputBlock.Text &= String.Format(vbCrLf & "The parameters for the method {0} that have custom attributes are : ", myMethods(i)) & vbCrLf
            For j As Integer = 0 To myParameters.Length - 1
               ' Get the attributes of type 'MyAttribute' for each parameter.
               Dim myAttributes As Object() = myParameters(j).GetCustomAttributes(GetType(MyAttribute), False)

               If myAttributes.Length > 0 Then
                  outputBlock.Text &= String.Format("Parameter {0}, name = {1}, type = {2} has attributes: ", _
                      myParameters(j).Position, myParameters(j).Name, myParameters(j).ParameterType) & vbCrLf
                  For k As Integer = 0 To myAttributes.Length - 1
                     outputBlock.Text &= String.Format(vbTab & "{0}", myAttributes(k)) & vbCrLf
                  Next k
               End If
            Next j
         End If
      Next i
   End Sub
End Class

' This code example produces the following output:
'
'The parameters for the method Void MyMethod(Int32) that have custom attributes are :
'Parameter 0, name = i, type = System.Int32 has attributes:
'        MyAttribute
'
'The parameters for the method Boolean Equals(System.Object) that have custom attributes are :

using System;
using System.Reflection;

// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.Parameter)]
public class MyAttribute : Attribute
{
   private string myName;
   public MyAttribute(string name)
   {
      myName = name;
   }
   public string Name
   {
      get
      {
         return myName;
      }
   }
}

// Define a class which has a custom attribute associated with one of the 
// parameters of a method. 
public class MyClass1
{
   public void MyMethod(
       [MyAttribute("This is an example parameter attribute")]
        int i)
   {
      return;
   }
}

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // Get the type of the class 'MyClass1'.
      Type myType = typeof(MyClass1);
      // Get the members associated with the class 'MyClass1'.
      MethodInfo[] myMethods = myType.GetMethods();

      // Display the attributes for each of the parameters of each method of the class 'MyClass1'.
      for (int i = 0; i < myMethods.Length; i++)
      {
         // Get the parameters for the method.
         ParameterInfo[] myParameters = myMethods[i].GetParameters();

         if (myParameters.Length > 0)
         {
            outputBlock.Text += String.Format("\nThe parameters for the method {0} that have custom attributes are :", myMethods[i]) + "\n";
            for (int j = 0; j < myParameters.Length; j++)
            {
               // Get the attributes of type 'MyAttribute' for each parameter.
               Object[] myAttributes = myParameters[j].GetCustomAttributes(typeof(MyAttribute), false);

               if (myAttributes.Length > 0)
               {
                  outputBlock.Text += String.Format("Parameter {0}, name = {1}, type = {2} has attributes: ",
                      myParameters[j].Position, myParameters[j].Name, myParameters[j].ParameterType) + "\n";
                  for (int k = 0; k < myAttributes.Length; k++)
                  {
                     outputBlock.Text += String.Format("\t{0}", myAttributes[k]) + "\n";
                  }
               }
            }
         }
      }
   }
}
/* This code example produces the following output:

The parameters for the method Void MyMethod(Int32) that have custom attributes are :
Parameter 0, name = i, type = System.Int32 has attributes:
        MyAttribute

The parameters for the method Boolean Equals(System.Object) that have custom attributes are :
 */