PropertyInfo.GetIndexParameters 方法

定义

命名空间:

System.Reflection

程序集:

System.Runtime.dll

Source:

PropertyInfo.cs

当在派生类中重写时，返回此属性的所有索引参数的数组。

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()

返回

ParameterInfo[]

ParameterInfo 类型的数组，它包含索引的参数。 如果未为该属性编制索引，则数组包含 0（零）个元素。

示例

以下示例显示指定属性的索引参数。

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

注解

从返回的数组中提取任何必需的参数信息。

若要使用 GetIndexParameters 方法，请先获取类 Type。 Type从 中获取 PropertyInfo。 在 中 PropertyInfo，使用 GetIndexParameters 方法。