FieldInfo Class
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Discovers the attributes of a field and provides access to field metadata.
Inheritance Hierarchy
System..::.Object
System.Reflection..::.MemberInfo
System.Reflection..::.FieldInfo
Namespace: System.Reflection
Assembly: mscorlib (in mscorlib.dll)
Syntax
Public MustInherit Class FieldInfo _
Inherits MemberInfo
public abstract class FieldInfo : MemberInfo
The FieldInfo type exposes the following members.
Properties
Name | Description | |
---|---|---|
Attributes | Gets the attributes that are associated with this field. | |
CustomAttributes | Gets a collection that contains this member's custom attributes. (Inherited from MemberInfo.) | |
DeclaringType | Gets the class that declares this member. (Inherited from MemberInfo.) | |
FieldHandle | Gets a handle to the internal metadata representation of a field. | |
FieldType | Gets the type of this field object. | |
IsAssembly | Gets a value that indicates whether the potential visibility of this field is described by FieldAttributes..::.Assembly; that is, the field is visible at most to other types in the same assembly, and is not visible to derived types outside the assembly. | |
IsFamily | 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. | |
IsFamilyAndAssembly | Gets a value that indicates whether the visibility of this field is described by FieldAttributes..::.FamANDAssem; that is, the field can be accessed from derived classes, but only if they are in the same assembly. | |
IsFamilyOrAssembly | Gets a value that indicates whether the potential visibility of this field is described by FieldAttributes..::.FamORAssem; that is, the field can be accessed by derived classes wherever they are, and by classes in the same assembly. | |
IsInitOnly | Gets a value that indicates whether the field can be set only in the body of the constructor. | |
IsLiteral | Gets a value that indicates whether the value is written at compile time and cannot be changed. | |
IsNotSerialized | Gets a value that indicates whether this field has the NotSerialized attribute. | |
IsPinvokeImpl | Gets a value that indicates whether the corresponding PinvokeImpl attribute is set in FieldAttributes. | |
IsPrivate | Gets a value that indicates whether the field is private. | |
IsPublic | Gets a value that indicates whether the field is public. | |
IsSpecialName | Gets a value that indicates whether the field has a name that has special significance. | |
IsStatic | Gets a value that indicates whether the field is static (Shared in Visual Basic). | |
MemberType | Gets a value that indicates that this member is a field. (Overrides MemberInfo..::.MemberType.) | |
MetadataToken | Gets a value that identifies a metadata element. (Inherited from MemberInfo.) | |
Module | Gets the module in which the type that declares the member represented by the current MemberInfo is defined. (Inherited from MemberInfo.) | |
Name | Gets the name of the current member. (Inherited from MemberInfo.) | |
ReflectedType | Gets the class object that was used to obtain this instance of MemberInfo. (Inherited from MemberInfo.) |
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Methods
Name | Description | |
---|---|---|
Equals | Returns a value that indicates whether this instance is equal to a specified object. (Overrides MemberInfo..::.Equals(Object).) | |
Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) | |
GetCustomAttributes(Boolean) | When overridden in a derived class, returns an array of all custom attributes applied to this member. (Inherited from MemberInfo.) | |
GetCustomAttributes(Type, Boolean) | When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type. (Inherited from MemberInfo.) | |
GetFieldFromHandle(RuntimeFieldHandle) | Gets a FieldInfo for the field represented by the specified handle. | |
GetFieldFromHandle(RuntimeFieldHandle, RuntimeTypeHandle) | Gets a FieldInfo for the field represented by the specified handle, for the specified generic type. | |
GetHashCode | Returns the hash code for this instance. (Overrides MemberInfo..::.GetHashCode()()().) | |
GetRawConstantValue | Returns a literal value associated with the field by a compiler. | |
GetType | Gets the Type of the current instance. (Inherited from Object.) | |
GetValue | When overridden in a derived class, returns the value of a field supported by a given object. | |
IsDefined | When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member. (Inherited from MemberInfo.) | |
MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) | |
SetValue(Object, Object) | Sets the value of the field that is supported by the given object. | |
SetValue(Object, Object, BindingFlags, Binder, CultureInfo) | When overridden in a derived class, sets the value of the field with the specified constraints on type conversion. | |
ToString | Returns a string that represents the current object. (Inherited from Object.) |
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Extension Methods
Name | Description | |
---|---|---|
GetCustomAttribute(Type) | Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttribute(Type, Boolean) | Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttribute<(Of <(T>)>)()()() | Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttribute<(Of <(T>)>)(Boolean) | Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttributes()()() | Overloaded. Retrieves a collection of custom attributes that are applied to a specified member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttributes(Type) | Overloaded. Retrieves a collection of custom attributes of a specified type that are applied to a specified member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttributes<(Of <(T>)>)()()() | Overloaded. Retrieves a collection of custom attributes of a specified type that are applied to a specified member. (Defined by CustomAttributeExtensions.) | |
GetCustomAttributes<(Of <(T>)>)(Boolean) | Overloaded. Retrieves a collection of custom attributes of a specified type that are applied to a specified member, and optionally inspects the ancestors of that member. (Defined by CustomAttributeExtensions.) | |
IsDefined | Indicates whether custom attributes of a specified type are applied to a specified member. (Defined by CustomAttributeExtensions.) |
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Remarks
The FieldInfo class does not have a public constructor. FieldInfo objects are obtained by calling either Type..::.GetFields or Type..::.GetField.
Fields are variables that are defined in the class. FieldInfo provides access to the metadata for a field in a class and also enables late-bound access to the value of a field. In Windows Phone, you can get the metadata of any field, regardless of its access level, but you cannot use FieldInfo to bypass access-level protection when you get or set the value of a field.
Examples
The following example uses the Type..::.GetFields method to get the fields of the Example class, and then displays information about the fields.
Note
To run this example, see Building examples that have static TextBlock controls for Windows Phone 8.
Imports System.Reflection
Public Class Example
Public myField1 As Integer = 0
Protected myField2 As String = Nothing
Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
Dim myFieldInfo() As FieldInfo
Dim myType As Type = GetType(Example)
' Get the type and fields of Example.
myFieldInfo = myType.GetFields(BindingFlags.NonPublic Or _
BindingFlags.Instance Or BindingFlags.Public)
outputBlock.Text &= ControlChars.NewLine & "The fields of " & _
"Example class are " & ControlChars.NewLine & vbCrLf
' Display the field information of Example.
Dim i As Integer
For i = 0 To myFieldInfo.Length - 1
outputBlock.Text &= String.Format(ControlChars.NewLine + "Name : {0}", myFieldInfo(i).Name) & vbCrLf
outputBlock.Text &= String.Format("Declaring Type : {0}", myFieldInfo(i).DeclaringType) & vbCrLf
outputBlock.Text &= String.Format("IsPublic : {0}", myFieldInfo(i).IsPublic) & vbCrLf
outputBlock.Text &= String.Format("MemberType : {0}", myFieldInfo(i).MemberType) & vbCrLf
outputBlock.Text &= String.Format("FieldType : {0}", myFieldInfo(i).FieldType) & vbCrLf
outputBlock.Text &= String.Format("IsFamily : {0}", myFieldInfo(i).IsFamily) & vbCrLf
Next i
End Sub
End Class
using System;
using System.Reflection;
public class Example
{
public int myField1 = 0;
protected string myField2 = null;
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
FieldInfo[] myFieldInfo;
Type myType = typeof(Example);
// Get the type and fields of Example.
myFieldInfo = myType.GetFields(BindingFlags.NonPublic | BindingFlags.Instance
| BindingFlags.Public);
outputBlock.Text += "\nThe fields of " +
"Example are \n" + "\n";
// Display the field information of Example.
for (int i = 0; i < myFieldInfo.Length; i++)
{
outputBlock.Text += String.Format("\nName : {0}", myFieldInfo[i].Name) + "\n";
outputBlock.Text += String.Format("Declaring Type : {0}", myFieldInfo[i].DeclaringType) + "\n";
outputBlock.Text += String.Format("IsPublic : {0}", myFieldInfo[i].IsPublic) + "\n";
outputBlock.Text += String.Format("MemberType : {0}", myFieldInfo[i].MemberType) + "\n";
outputBlock.Text += String.Format("FieldType : {0}", myFieldInfo[i].FieldType) + "\n";
outputBlock.Text += String.Format("IsFamily : {0}", myFieldInfo[i].IsFamily) + "\n";
}
}
}
Version Information
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone
Thread Safety
This type is thread safe.