PropertyInfo.CanWrite Properti

Definisi

Ruang nama:

System.Reflection

Rakitan:

System.Runtime.dll

Sumber:

PropertyInfo.cs

Mendapatkan nilai yang menunjukkan apakah properti dapat ditulis.

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

public abstract bool CanWrite { get; }

member this.CanWrite : bool

Public MustOverride ReadOnly Property CanWrite As Boolean

Nilai Properti

Boolean

true jika properti ini dapat ditulis ke; jika tidak, false.

Contoh

Contoh berikut mendefinisikan dua properti. Properti pertama dapat ditulis dan CanWrite propertinya adalah true. Properti kedua tidak dapat ditulis (tidak set ada aksesor), dan CanWrite propertinya adalah false.

using namespace System;
using namespace System::Reflection;

// Define one writable property and one not writable.
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 
   {
      String^ get()
      {
         return caption;
      }

   }

};

int main()
{
   Console::WriteLine( "\nReflection.PropertyInfo" );
   
   // Define two properties.
   Mypropertya^ mypropertya = gcnew Mypropertya;
   Mypropertyb^ mypropertyb = gcnew Mypropertyb;
   
   // Read and display the property.
   Console::Write( "\nMypropertya->Caption = {0}", mypropertya->Caption );
   Console::Write( "\nMypropertyb->Caption = {0}", mypropertyb->Caption );
   
   // Write to the property.
   mypropertya->Caption = "A- No Change";
   
   // Mypropertyb.Caption cannot be written to because
   // there is no set accessor.
   // Read and display the property.
   Console::Write( "\nMypropertya->Caption = {0}", mypropertya->Caption );
   Console::Write( "\nMypropertyb->Caption = {0}", mypropertyb->Caption );
   
   // 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 CanWrite property.
   Console::Write( "\nCanWrite a - {0}", Mypropertyinfoa->CanWrite );
   Console::Write( "\nCanWrite b - {0}", Mypropertyinfob->CanWrite );
   return 0;
}

using System;
using System.Reflection;

 // Define one writable property and one not writable.
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
    {
        get{return caption;}
    }
}

class Mypropertyinfo
{
    public static int Main()
    {
        Console.WriteLine("\nReflection.PropertyInfo");

        // Define two properties.
        Mypropertya Mypropertya = new Mypropertya();
        Mypropertyb Mypropertyb = new Mypropertyb();

        // Read and display the property.
        Console.Write("\nMypropertya.Caption = " + Mypropertya.Caption);
        Console.Write("\nMypropertyb.Caption = " + Mypropertyb.Caption);

        // Write to the property.
        Mypropertya.Caption = "A- No Change";
        // Mypropertyb.Caption cannot be written to because
        // there is no set accessor.

        // Read and display the property.
        Console.Write("\nMypropertya.Caption = " + Mypropertya.Caption);
        Console.Write ("\nMypropertyb.Caption = " + Mypropertyb.Caption);

        // 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 CanWrite property.

        Console.Write("\nCanWrite a - " + Mypropertyinfoa.CanWrite);

        Console.Write("\nCanWrite b - " + Mypropertyinfob.CanWrite);

        return 0;
    }
}

Imports System.Reflection

' Define one writable property and one not writable.
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 ReadOnly Property Caption() As String
        Get
            Return myCaption
        End Get
    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()

        ' Read and display the property.
        Console.Write(ControlChars.CrLf & "Mypropertya.Caption = " & _
           Mypropertya.Caption)
        Console.Write(ControlChars.CrLf & "Mypropertyb.Caption = " & _
           Mypropertyb.Caption)

        ' Write to the property.
        Mypropertya.Caption = "A- No Change"
        ' Mypropertyb.Caption cannot be written to because
        ' there is no set accessor.
        ' Read and display the property.
        Console.Write(ControlChars.CrLf & "Mypropertya.Caption = " & _
           Mypropertya.Caption)
        Console.Write(ControlChars.CrLf & "Mypropertyb.Caption = " & _
           Mypropertyb.Caption)

        ' 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 CanWrite property.
        Console.Write(ControlChars.CrLf & "CanWrite a - " & _
           Mypropertyinfoa.CanWrite)

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

        Return 0
    End Function
End Class

Keterangan

CanWritetrue mengembalikan jika properti memiliki set aksesor, bahkan jika aksesor adalah private, internal (atau Friend di Visual Basic), atau protected. Jika properti tidak memiliki set aksesor, metode akan mengembalikan false.

Untuk mendapatkan nilai CanWrite properti:

1. Type Dapatkan objek jenis yang menyertakan properti .

2. Type.GetProperty Panggil untuk mendapatkan PropertyInfo objek yang mewakili properti .

3. Ambil nilai CanWrite properti .