PropertyInfo.CanRead 屬性

定義

命名空間:

System.Reflection

組件:

System.Runtime.dll

來源:

PropertyInfo.cs

取得值，指出是否可讀取屬性。

public:
 abstract property bool CanRead { bool get(); };

public abstract bool CanRead { get; }

member this.CanRead : bool

Public MustOverride ReadOnly Property CanRead As Boolean

屬性值

Boolean

如果可讀取這個屬性，則為 true，否則為 false。

範例

下列範例會定義兩個屬性。 第一個屬性是可讀取的 CanRead ，而 屬性為 true。 第二個屬性無法讀取， (沒有 get 存取子) ，而 CanRead 屬性為 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

備註

如果屬性沒有 get 存取子，則無法讀取它。

若要取得 CanRead 屬性，請先取得 類別 Type。 從取得 TypePropertyInfo。 從取得 PropertyInfoCanRead 值。