共用方式為

  • 發行項

FieldInfo.IsFamily Property

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Gets a value that indicates whether the visibility of this field is described by FieldAttributes.Family; that is, the field is visible only within its class and derived classes.

Namespace:  System.Reflection
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public ReadOnly Property IsFamily As Boolean

public bool IsFamily { get; }

Property Value

Type: System.Boolean
true if access to this field is exactly described by FieldAttributes.Family; otherwise, false.

Exceptions

Exception Condition
MethodAccessException

This member is invoked late-bound through mechanisms such as Type.InvokeMember.

Remarks

The visibility of a field is exactly described by FieldAttributes.Family if the only visibility modifier is protected. This property is false for fields that are protected internal in C# (Protected Friend in Visual Basic, protected public in C++); use the IsFamilyOrAssembly property to identify such fields.

Examples

The following example defines fields with varying levels of visibility, and displays the values of their IsAssembly, IsFamily, IsFamilyOrAssembly, and IsFamilyAndAssembly properties.

NoteNote:

The Visual Basic and C# languages cannot define fields with FieldAttributes.FamANDAssem visibility.

To run this example, see Building Examples That Use a Demo Method and a TextBlock Control.

Imports System.Reflection

Public Class Example

   Public f_Public As Integer
   Friend f_Friend As Integer
   Protected f_Protected As Integer
   Protected Friend f_Protected_Friend As Integer

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      outputBlock.FontFamily = New FontFamily("Courier New")
      outputBlock.Text &= String.Format(vbCrLf & _
          "{0,-30}{1,-18}{2}", "", "IsAssembly", "IsFamilyOrAssembly") & vbCrLf
      outputBlock.Text &= String.Format("{0,-21}{1,-18}{2,-18}{3}" & vbCrLf, _
          "", "IsPublic", "IsFamily", "IsFamilyAndAssembly") & vbCrLf

      For Each f As FieldInfo In GetType(Example).GetFields( _
          BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public)

         outputBlock.Text &= String.Format("{0,-21}{1,-9}{2,-9}{3,-9}{4,-9}{5,-9}", _
             f.Name, _
             f.IsPublic, _
             f.IsAssembly, _
             f.IsFamily, _
             f.IsFamilyOrAssembly, _
             f.IsFamilyAndAssembly _
         ) & vbCrLf
      Next
   End Sub
End Class

' This code example produces output similar to the following:
'
'                              IsAssembly        IsFamilyOrAssembly
'                     IsPublic          IsFamily          IsFamilyAndAssembly
'
'f_Public             True     False    False    False    False
'f_Friend             False    True     False    False    False
'f_Protected          False    False    True     False    False
'f_Protected_Friend   False    False    False    True     False

using System;
using System.Reflection;

public class Example
{
   public int f_public;
   internal int f_internal;
   protected int f_protected;
   protected internal int f_protected_public;

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      outputBlock.FontFamily = new System.Windows.Media.FontFamily("Courier New");
      outputBlock.Text += String.Format("\n{0,-30}{1,-18}{2}", "", "IsAssembly", "IsFamilyOrAssembly") + "\n";
      outputBlock.Text += String.Format("{0,-21}{1,-18}{2,-18}{3}\n",
          "", "IsPublic", "IsFamily", "IsFamilyAndAssembly") + "\n";

      foreach (FieldInfo f in typeof(Example).GetFields(
          BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public))
      {
         outputBlock.Text += String.Format("{0,-21}{1,-9}{2,-9}{3,-9}{4,-9}{5,-9}",
             f.Name,
             f.IsPublic,
             f.IsAssembly,
             f.IsFamily,
             f.IsFamilyOrAssembly,
             f.IsFamilyAndAssembly
         ) + "\n";
      }
   }
}

/* This code example produces output similar to the following:

                              IsAssembly        IsFamilyOrAssembly
                     IsPublic          IsFamily          IsFamilyAndAssembly

f_public             True     False    False    False    False
f_internal           False    True     False    False    False
f_protected          False    False    True     False    False
f_protected_public   False    False    False    True     False
 */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.