PropertyInfo.CanRead Propriedade

Definição

Obtém um valor que indica se a propriedade pode ser lida.Gets a value indicating whether the property can be read.

public:
 abstract property bool CanRead { bool get(); };
public abstract bool CanRead { get; }
member this.CanRead : bool
Public MustOverride ReadOnly Property CanRead As Boolean

Valor da propriedade

true se essa propriedade puder ser lida; caso contrário, false.true if this property can be read; otherwise, false.

Implementações

Exemplos

O exemplo a seguir define duas propriedades.The following example defines two properties. A primeira propriedade é legível e a CanRead propriedade é true.The first property is readable and the CanRead property is true. A segunda propriedade não é legível (não há nenhum acessador get) e CanRead a propriedade falseé.The second property is not readable (there is no get accessor), and the CanRead property is false.

using namespace System;
using namespace System::Reflection;

// Define one readable property and one not readable.
public ref class Mypropertya
{
private:
   String^ caption;

public:
   Mypropertya()
      : caption( "A Default caption" )
   {}


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

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

   }

};

public ref class Mypropertyb
{
private:
   String^ caption;

public:
   Mypropertyb()
      : caption( "B Default caption" )
   {}


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

   }

};

int main()
{
   Console::WriteLine( "\nReflection.PropertyInfo" );
   
   // Define two properties.
   Mypropertya^ mypropertya = gcnew Mypropertya;
   Mypropertyb^ mypropertyb = gcnew Mypropertyb;
   Console::Write( "\nMypropertya->Caption = {0}", mypropertya->Caption );
   
   // Mypropertyb.Caption cannot be read, because
   // there is no get accessor.
   // Get the type and PropertyInfo.
   Type^ MyTypea = Type::GetType( "Mypropertya" );
   PropertyInfo^ Mypropertyinfoa = MyTypea->GetProperty( "Caption" );
   Type^ MyTypeb = Type::GetType( "Mypropertyb" );
   PropertyInfo^ Mypropertyinfob = MyTypeb->GetProperty( "Caption" );
   
   // Get and display the CanRead property.
   Console::Write( "\nCanRead a - {0}", Mypropertyinfoa->CanRead );
   Console::Write( "\nCanRead b - {0}", Mypropertyinfob->CanRead );
   return 0;
}

using System;
using System.Reflection;
 
// Define one readable property and one not readable.
public class Mypropertya
{
    private string caption = "A Default caption";
    public string Caption
    {
        get{return caption;}
        set {if(caption!=value) {caption = value;}
        }
    }
}
public class Mypropertyb
{
    private string caption = "B Default caption";
    public string Caption
    {
        set{if(caption!=value) {caption = value;}
        }
    }
}
  
class Mypropertyinfo
{
    public static int Main()
    {
        Console.WriteLine("\nReflection.PropertyInfo");
  
        // Define two properties.
        Mypropertya Mypropertya = new Mypropertya();
        Mypropertyb Mypropertyb = new Mypropertyb();
  
        Console.Write("\nMypropertya.Caption = " + Mypropertya.Caption);
        // Mypropertyb.Caption cannot be read, because
        // there is no get accessor.
  
        // Get the type and PropertyInfo.
        Type MyTypea = Type.GetType("Mypropertya");
        PropertyInfo Mypropertyinfoa = MyTypea.GetProperty("Caption");
        Type MyTypeb = Type.GetType("Mypropertyb");
        PropertyInfo Mypropertyinfob = MyTypeb.GetProperty("Caption");
  
        // Get and display the CanRead property.
        Console.Write("\nCanRead a - " + Mypropertyinfoa.CanRead);
        Console.Write("\nCanRead b - " + Mypropertyinfob.CanRead);
  
        return 0;
    }
}
Imports System.Reflection

' Define one readable property and one not readable.
Public Class Mypropertya
    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
End Class

Public Class Mypropertyb
    Private myCaption As String = "B Default caption"

    Public WriteOnly Property Caption() As String
        Set(ByVal Value As String)
            If myCaption <> value Then
                myCaption = value
            End If
        End Set
    End Property
End Class

Class Mypropertyinfo

    Public Shared Function Main() As Integer
        Console.WriteLine(ControlChars.CrLf & "Reflection.PropertyInfo")

        ' Define two properties.
        Dim Mypropertya As New Mypropertya()
        Dim Mypropertyb As New Mypropertyb()

        Console.Write(ControlChars.Cr & "Mypropertya.Caption = " & _
           Mypropertya.Caption)
        ' Mypropertyb.Caption cannot be read because
        ' there is no get accessor.
        ' Get the type and PropertyInfo.
        Dim MyTypea As Type = Type.GetType("Mypropertya")
        Dim Mypropertyinfoa As PropertyInfo = MyTypea.GetProperty("Caption")
        Dim MyTypeb As Type = Type.GetType("Mypropertyb")
        Dim Mypropertyinfob As PropertyInfo = MyTypeb.GetProperty("Caption")

        ' Get and display the CanRead property.
        Console.Write(ControlChars.CrLf & "CanRead a - " & _
           Mypropertyinfoa.CanRead)

        Console.Write(ControlChars.CrLf & "CanRead b - " & _
           Mypropertyinfob.CanRead)

        Return 0
    End Function
End Class

Comentários

Se a propriedade não tiver um get acessador, ela não poderá ser lida.If the property does not have a get accessor, it cannot be read.

Para obter a CanRead Propriedade, primeiro obtenha a classe Type.To get the CanRead property, first get the class Type. No, obtenha o PropertyInfo. TypeFrom the Type, get the PropertyInfo. No, obtenha o CanRead valor. PropertyInfoFrom the PropertyInfo, get the CanRead value.

Aplica-se a