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ParameterInfo.Attributes Property

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Gets the attributes for this parameter.

Namespace:  System.Reflection
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public Overridable ReadOnly Property Attributes As ParameterAttributes
public virtual ParameterAttributes Attributes { get; }

Property Value

Type: System.Reflection.ParameterAttributes
The attributes for this parameter.

Remarks

To get the ParameterInfo array, first get the method or the constructor, and then call MethodBase.GetParameters.

Examples

The following example defines a method with four parameters and uses the Attributes property to display the attributes of the parameters.

Imports System.Reflection
Imports System.Runtime.InteropServices

Class Example

   Public Shared Sub mymethod(ByVal str1 As String, ByRef str2 As String, _
      <Out> ByRef str3 As String, <InAttribute> ByVal str4 As String)

      ' Add str1 to str2, which is ByRef.
      str2 &= str1
      ' When mymethod is called, str3 has no value. Give it one.
      str3 = "new value"
   End Sub

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) 

      ' Get the method.
      Dim mm As MethodInfo = GetType(Example).GetMethod("mymethod")

      ' Display the method.
      outputBlock.Text &= "MethodInfo.ToString(): " & mm.ToString() & vbCrLf

      For Each param In mm.GetParameters()

         outputBlock.Text &= String.Format("Attributes for parameter {0}, ""{1}"": {2} ({3})", _ 
            param.Position, param.Name, param.Attributes, CInt(param.Attributes))

         If param.ParameterType.IsByRef Then
            outputBlock.Text &= "; the parameter type is ByRef" & vbLf
         Else
            outputBlock.Text &= vbLf
         End If
      Next
   End Sub
End Class

' This code produces the following output:
'
'MethodInfo.ToString(): Void mymethod(System.String, System.String ByRef, System.String ByRef)
'Attributes for parameter 0, "str1": None (0)
'Attributes for parameter 1, "str2": None (0); the parameter type is ByRef
'Attributes for parameter 2, "str3": Out (2); the parameter type is ByRef
'Attributes for parameter 3, "str4": In (1)
using System;
using System.Reflection;
using System.Runtime.InteropServices;

class Example
{
   public static void mymethod(string str1, ref string str2, out string str3,
      [In] string str4)
   {
      // Concatenate str1 to str2, which is ref.
      str2 += str1;
      // When mymethod is called, str3 has no value. Give it one.
      str3 = "new value";
   }

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      MethodInfo mm = typeof(Example).GetMethod("mymethod");

      // Display the method.
      outputBlock.Text += "MethodInfo.ToString(): " + mm.ToString() + "\n";

      // Get and display the attributes for the second parameter.
      foreach (ParameterInfo param in mm.GetParameters())
      {
         outputBlock.Text += String.Format("Attributes for parameter {0}, \"{1}\": {2} ({3})",  
            param.Position, param.Name, param.Attributes, (int)param.Attributes);

         if (param.ParameterType.IsByRef)
         {
            outputBlock.Text += "; the parameter type is ref\n";
         }
         else
         {
            outputBlock.Text += "\n";
         }
      }
   }
}

/* This code produces the following output:

MethodInfo.ToString(): Void mymethod(System.String, System.String ByRef, System.String ByRef)
Attributes for parameter 0, "str1": None (0)
Attributes for parameter 1, "str2": None (0); the parameter type is ByRef
Attributes for parameter 2, "str3": Out (2); the parameter type is ByRef
Attributes for parameter 3, "str4": In (1)
 */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.