PropertyInfo.GetIndexParameters Method

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

PropertyInfo.cs

When overridden in a derived class, returns an array of all the index parameters for the property.

public:
 abstract cli::array <System::Reflection::ParameterInfo ^> ^ GetIndexParameters();

public abstract System.Reflection.ParameterInfo[] GetIndexParameters ();

abstract member GetIndexParameters : unit -> System.Reflection.ParameterInfo[]

Public MustOverride Function GetIndexParameters () As ParameterInfo()

Returns

ParameterInfo[]

An array of type ParameterInfo containing the parameters for the indexes. If the property is not indexed, the array has 0 (zero) elements.

Examples

The following example displays the index parameters of the specified property.

using namespace System;
using namespace System::Reflection;

// A class that contains some properties.
public ref class MyProperty
{
private:

   // Define a simple string property.
   String^ caption;

public:

   property String^ Caption 
   {
      String^ get()
      {
         return caption;
      }

      void set( String^ value )
      {
         if ( caption != value )
         {
            caption = value;
         }
      }

   }

private:

   // A very limited indexer that gets or sets one of four 
   // strings.
   array<String^>^strings;

public:
   MyProperty()
   {
      array<String^>^temp0 = {"abc","def","ghi","jkl"};
      strings = temp0;
   }


   property String^ Item [int]
   {
      String^ get( int Index )
      {
         return strings[ Index ];
      }

      void set( int Index, String^ value )
      {
         strings[ Index ] = value;
      }

   }

};

int main()
{
   
   // Get the type and PropertyInfo.
   Type^ t = Type::GetType( "MyProperty" );
   PropertyInfo^ pi = t->GetProperty( "Caption" );
   
   // Get the public GetIndexParameters method.
   array<ParameterInfo^>^parms = pi->GetIndexParameters();
   Console::WriteLine( "\n{0}.{1} has {2} parameters.", t->FullName, pi->Name, parms->GetLength( 0 ) );
   
   // Display a property that has parameters. 
   pi = t->GetProperty( "Item" );
   parms = pi->GetIndexParameters();
   Console::WriteLine( "{0}.{1} has {2} parameters.", t->FullName, pi->Name, parms->GetLength( 0 ) );
   for ( int i = 0; i < parms->GetLength( 0 ); i++ )
   {
      Console::WriteLine( "    Parameter: {0}", parms[ i ]->Name );

   }
   return 0;
}

/*
 This example produces the following output:
 MyProperty.Caption has 0 parameters.
 MyProperty.Item has 1 parameters.
    Parameter: Index
 */

using System;
using System.Reflection;

// A class that contains some properties.
public class MyProperty
{
    // Define a simple string property.
    private string caption = "A Default caption";
    public string Caption
    {
        get{return caption;}
        set {if(caption!=value) {caption = value;}
        }
    }

    // A very limited indexer that gets or sets one of four
    // strings.
    private string[] strings = {"abc", "def", "ghi", "jkl"};
    public string this[int Index]
    {
        get
        {
            return strings[Index];
        }
        set
        {
            strings[Index] = value;
        }
    }
}

class Mypropertyinfo
{
    public static int Main()
    {
        // Get the type and PropertyInfo.
        Type t = Type.GetType("MyProperty");
        PropertyInfo pi = t.GetProperty("Caption");

        // Get the public GetIndexParameters method.
        ParameterInfo[] parms = pi.GetIndexParameters();
        Console.WriteLine("\r\n" + t.FullName + "." + pi.Name
            + " has " + parms.GetLength(0) + " parameters.");

        // Display a property that has parameters. The default
        // name of an indexer is "Item".
        pi = t.GetProperty("Item");
        parms = pi.GetIndexParameters();
        Console.WriteLine(t.FullName + "." + pi.Name + " has " +
            parms.GetLength(0) + " parameters.");
        foreach( ParameterInfo p in parms )
        {
            Console.WriteLine("   Parameter: " + p.Name);
        }

        return 0;
    }
}
/*
 This example produces the following output:
 MyProperty.Caption has 0 parameters.
 MyProperty.Item has 1 parameters.
    Parameter: Index
 */

Imports System.Reflection
Imports System.Collections

' A test class that has some properties.
Public Class MyProperty

    ' Define a simple string property.
    Private myCaption As String = "A Default caption"
    Public Property Caption() As String
        Get
            Return myCaption
        End Get
        Set(ByVal Value As String)
            If myCaption <> value Then
                myCaption = value
            End If
        End Set
    End Property

    ' A very limited indexed default property that gets or
    ' sets one of four string values.
    Private strings() As String = {"abc", "def", "ghi", "jkl"}
    Public Default Property Item(ByVal Index As Integer) As String
        Get
            Return strings(Index)
        End Get
        Set
            strings(Index) = Value
        End Set 
    End Property
End Class

Public Class Example

    Public Shared Function Main() As Integer

        ' Get the type and PropertyInfo.
        Dim t As Type = GetType(MyProperty)
        Dim pi As PropertyInfo = t.GetProperty("Caption")

        ' Get an array containing the parameters (if any).
        Dim params As ParameterInfo() = pi.GetIndexParameters()
        Console.WriteLine(vbCrLf & t.FullName & "." & pi.Name & _
           " has " & params.GetLength(0) & " parameters.")

        ' Display a property that has parameters.
        pi = t.GetProperty("Item")
        params = pi.GetIndexParameters()
        Console.WriteLine(t.FullName & "." & pi.Name & _
           " has " & params.GetLength(0) & " parameters.")
        For Each p As ParameterInfo In params
            Console.WriteLine("   Parameter: " & p.Name)
        Next

        Return 0
    End Function
End Class

' This example produces the following output:
' MyProperty.Caption has 0 parameters.
' MyProperty.Item has 1 parameters.
'    Parameter: Index

Remarks

Extract any required parameter information from the returned array.

To use the GetIndexParameters method, first get the class Type. From the Type, get the PropertyInfo. From the PropertyInfo, use the GetIndexParameters method.