PropertyInfo.CanWrite Egenskap

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

public abstract bool CanWrite { get; }

member this.CanWrite : bool

Public MustOverride ReadOnly Property CanWrite As Boolean

Egenskapsvärde

trueom den här egenskapen kan skrivas till; annars . false

Implementeringar

Exempel

I följande exempel definieras två egenskaper. Den första egenskapen är skrivbar och egenskapen CanWrite är true. Den andra egenskapen är inte skrivbar (det finns ingen set accessor) och egenskapen CanWrite är false.

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

Kommentarer

CanWrite returnerar true om egenskapen har en set-accessor, även om accessorn är private, internal (eller Friend i Visual Basic) eller protected. Om egenskapen inte har någon set accessor returnerar falsemetoden .

Så här hämtar du värdet för CanWrite egenskapen:

1. Hämta objektet Type av den typ som innehåller egenskapen.

2. Type.GetProperty Anropa för att hämta objektet PropertyInfo som representerar egenskapen.

3. Hämta värdet för CanWrite egenskapen.