FieldInfo.GetValue Method

Parameters

• obj
  Type: System.Object
  The object whose field value will be returned.

Return Value

Type: System.Object
An object that contains the value of the field reflected by this instance.

Imports System.Reflection

Public Class Test

    Public Shared SA As String = "A public shared field."
    Friend Shared SB As String = "A friend shared field."
    Protected Shared SC As String = "A protected shared field."
    Private Shared SD As String = "A private shared field."

    Public A As String = "A public instance field."
    Friend B As String = "A friend instance field."
    Protected C As String = "A protected instance field."
    Private D As String = "A private instance field."

End Class

Public Class Example

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

        ' Create an instance of Test, and get a Type object.
        Dim myInstance As New Test()
        Dim t As Type = GetType(Test)

        ' Get the shared fields of Test, and display their values. This does not 
        ' require an instance of Test, so Nothing is passed to GetValue.
        Dim sharedFields As FieldInfo() = _
            t.GetFields(BindingFlags.Public Or BindingFlags.NonPublic Or BindingFlags.Static)
        For Each f As FieldInfo In sharedFields
            Try
                outputBlock.Text += _
                    String.Format("The value of Shared field {0} is: {1}" & vbLf, _
                                  f.Name, _
                                  f.GetValue(Nothing))
            Catch 
                outputBlock.Text += _
                    String.Format("The value of Shared field {0} is not accessible." & vbLf, _
                                  f.Name)
            End Try
        Next f

        ' Get the instance fields of Test, and display their values for the instance 
        ' created earlier.
        Dim instanceFields As FieldInfo() = _
            t.GetFields(BindingFlags.Public Or BindingFlags.NonPublic Or BindingFlags.Instance)
        For Each f As FieldInfo In instanceFields
            Try
                outputBlock.Text += _
                    String.Format("The value of instance field {0} is: {1}" & vbLf, _
                                  f.Name, _
                                  f.GetValue(myInstance))
            Catch 
                outputBlock.Text += _
                    String.Format("The value of instance field {0} is not accessible." & vbLf, _
                                  f.Name)
            End Try
        Next f

   End Sub

End Class 

' This example produces the following output:
'
'The value of Shared field SA is: A public shared field.
'The value of Shared field SB is: A friend shared field.
'The value of Shared field SC is not accessible.
'The value of Shared field SD is not accessible.
'The value of instance field A is: A public instance field.
'The value of instance field B is: A friend instance field.
'The value of instance field C is not accessible.
'The value of instance field D is not accessible.

using System;
using System.Reflection;

public class Test
{
    public static string SA = "A public shared field.";
    internal static string SB = "A friend shared field.";
    protected static string SC = "A protected shared field.";
    private static string SD = "A private shared field.";

    public string A = "A public instance field.";
    internal string B = "A friend instance field.";
    protected string C = "A protected instance field.";
    private string D = "A private instance field.";
}

public class Example
{
    public static void Demo(System.Windows.Controls.TextBlock outputBlock)
    {
        // Create an instance of Test, and get a Type object.
        Test myInstance = new Test();
        Type t = typeof(Test);

        // Get the shared fields of Test, and display their values. This does not 
        // require an instance of Test, so null is passed to GetValue.
        FieldInfo[] sharedFields = 
            t.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static);
        foreach( FieldInfo f in sharedFields )
        {
            try
            {
                outputBlock.Text += 
                    String.Format("The value of Shared field {0} is: {1}\n", 
                                  f.Name, 
                                  f.GetValue(null));
            }
            catch
            {
                outputBlock.Text += 
                    String.Format("The value of Shared field {0} is not accessible.\n", 
                                  f.Name);
            }
        }

        // Get the instance fields of Test, and display their values for the instance 
        // created earlier.
        FieldInfo[] instanceFields = 
            t.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
        foreach( FieldInfo f in instanceFields )
        {
            try
            {
                outputBlock.Text += String.Format("The value of instance field {0} is: {1}\n", 
                                                  f.Name, 
                                                  f.GetValue(myInstance));
            }
            catch
            {
                outputBlock.Text += 
                    String.Format("The value of instance field {0} is not accessible.\n", 
                                  f.Name);
            }
        }
    }
}

/* This example produces the following output:

The value of Shared field SA is: A public shared field.
The value of Shared field SB is: A friend shared field.
The value of Shared field SC is not accessible.
The value of Shared field SD is not accessible.
The value of instance field A is: A public instance field.
The value of instance field B is: A friend instance field.
The value of instance field C is not accessible.
The value of instance field D is not accessible.
 */