dotnet-api-docs/xml/System.Reflection/FieldInfo.xml at main · dotnet/dotnet-api-docs

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<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

</TypeForwardingChain>

<Base>

<BaseTypeName>System.Reflection.MemberInfo</BaseTypeName>

</Base>

<InterfaceName>System.Runtime.InteropServices._FieldInfo</InterfaceName>

</Interface>

</Interfaces>

<AttributeName Language="C#">[System.Runtime.CompilerServices.Nullable(0)]</AttributeName>

</Attribute>

<AttributeName Language="C#">[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]</AttributeName>

</Attribute>

<AttributeName Language="C#">[System.Serializable]</AttributeName>

</Attribute>

<AttributeName Language="C#">[System.Runtime.InteropServices.ComDefaultInterface(typeof(System.Runtime.InteropServices._FieldInfo))]</AttributeName>

</Attribute>

<AttributeName Language="C#">[System.Runtime.InteropServices.ComVisible(true)]</AttributeName>

</Attribute>

</Attributes>

<Docs>

<summary>Discovers the attributes of a field and provides access to field metadata.</summary>

<format type="text/markdown"><![CDATA[

## Remarks

The field information is obtained from metadata. The <xref:System.Reflection.FieldInfo> class does not have a public constructor. <xref:System.Reflection.FieldInfo> objects are obtained by calling either the <xref:System.Type.GetFields%2A> or <xref:System.Type.GetField%2A> method of a `Type` object.

Fields are variables defined in the class. <xref:System.Reflection.FieldInfo> provides access to the metadata for a field within a class and provides dynamic set and get functionality for the field. The class is not loaded into memory until invoke or get is called on the object.

## Examples

The following example uses the <xref:System.Type.GetFields%2A?displayProperty=nameWithType> method to get the field-related information from the <xref:System.Reflection.FieldInfo> class, and then displays field attributes.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/Overview/fieldinfo.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/Overview/fieldinfo.vb" id="Snippet1":::

]]></format>

</remarks>

<threadsafe>This type is thread safe.</threadsafe>

<para>When you inherit from <see cref="T:System.Reflection.FieldInfo" />, you must override the following members: <see cref="M:System.Reflection.FieldInfo.GetValue(System.Object)" /> and <see cref="M:System.Reflection.FieldInfo.SetValue(System.Object,System.Object,System.Reflection.BindingFlags,System.Reflection.Binder,System.Globalization.CultureInfo)" />.</para>

</block>

</Docs>

<MemberType>Constructor</MemberType>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<Docs>

<summary>Initializes a new instance of the <see langword="FieldInfo" /> class.</summary>

<remarks>To be added.</remarks>

</Docs>

</Member>

<MemberType>Property</MemberType>

<InterfaceMember FrameworkAlternate="netframework-1.1;netframework-2.0;netframework-3.0;netframework-3.5;netframework-4.0;netframework-4.5;netframework-4.5.1;netframework-4.5.2;netframework-4.6;netframework-4.6.1;netframework-4.6.2;netframework-4.7;netframework-4.7.1;netframework-4.7.2;netframework-4.8;netframework-4.8.1">P:System.Runtime.InteropServices._FieldInfo.Attributes</InterfaceMember>

</Implements>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Reflection.FieldAttributes</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets the attributes associated with this field.</summary>

<value>The <see langword="FieldAttributes" /> for this field.</value>

<format type="text/markdown"><![CDATA[

## Remarks

All members have a set of attributes, which are defined in relation to the specific type of member. `FieldAttributes` informs the user whether this field is the private field, a static field, and so on.

To get the `Attributes` property, first get the class `Type`. From the `Type`, get the `FieldInfo`. From the `FieldInfo`, get the `Attributes`.

## Examples

The following code example builds three fields and displays their field attributes. A `FieldAttributes` value can contain more than one attribute, such as both `Public` and `Literal`, as shown in the third field.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldAttributes/Overview/source.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldAttributes/Overview/source.vb" id="Snippet1":::

]]></format>

</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="override this.Equals : obj -> bool" Usage="fieldInfo.Equals obj" />

<MemberType>Method</MemberType>

<InterfaceMember FrameworkAlternate="netframework-4.0;netframework-4.5;netframework-4.5.1;netframework-4.5.2;netframework-4.6;netframework-4.6.1;netframework-4.6.2;netframework-4.7;netframework-4.7.1;netframework-4.7.2;netframework-4.8;netframework-4.8.1">M:System.Runtime.InteropServices._FieldInfo.Equals(System.Object)</InterfaceMember>

</Implements>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Boolean</ReturnType>

</ReturnValue>

</Parameters>

<Docs>

<param name="obj">An object to compare with this instance, or <see langword="null" />.</param>

<summary>Returns a value that indicates whether this instance is equal to a specified object.</summary>

<see langword="true" /> if <paramref name="obj" /> equals the type and value of this instance; otherwise, <see langword="false" />.</returns>

<remarks>To be added.</remarks>

</Docs>

</Member>

<MemberType>Property</MemberType>

</Implements>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<ReturnType>System.RuntimeFieldHandle</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets a <see langword="RuntimeFieldHandle" />, which is a handle to the internal metadata representation of a field.</summary>

<value>A handle to the internal metadata representation of a field.</value>

<format type="text/markdown"><![CDATA[

## Remarks

The handles are valid only in the appdomain in which they were obtained.

## Examples

The following example retrieves MyClass.MyField field information and displays the field associated with the field handle.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/FieldHandle/fieldinfo_fieldhandle.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/FieldHandle/fieldinfo_fieldhandle.vb" id="Snippet1":::

]]></format>

</remarks>

</Docs>

</Member>

<MemberType>Property</MemberType>

</Implements>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Type</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets the type of this field object.</summary>

<value>The type of this field object.</value>

<format type="text/markdown"><![CDATA[

## Remarks

The type is some primitive data type, such as `String`, `Boolean`, or `GUID`.

To get the `FieldType` property, first get the class `Type`. From the `Type`, get the `FieldInfo`. From the `FieldInfo`, get the `FieldType` value.

## Examples

The following example creates a field, gets its type and <xref:System.Reflection.FieldInfo>, and displays its <xref:System.Reflection.FieldInfo.FieldType%2A>.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/FieldType/source.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/FieldType/source.vb" id="Snippet1":::

]]></format>

</remarks>

</Docs>

</Member>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<Docs>

<summary>Gets a <see cref="T:System.Reflection.FieldInfo" /> for the field represented by a handle.</summary>

</Docs>

</MemberGroup>

<MemberSignature Language="F#" Value="static member GetFieldFromHandle : RuntimeFieldHandle -> System.Reflection.FieldInfo" Usage="System.Reflection.FieldInfo.GetFieldFromHandle handle" />

<MemberType>Method</MemberType>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AttributeName Language="C#">[System.Security.SecuritySafeCritical]</AttributeName>

</Attribute>

</Attributes>

<ReturnType>System.Reflection.FieldInfo</ReturnType>

</ReturnValue>

</Parameters>

<Docs>

<param name="handle">A <see cref="T:System.RuntimeFieldHandle" /> structure that contains the handle to the internal metadata representation of a field.</param>

<summary>Gets a <see cref="T:System.Reflection.FieldInfo" /> for the field represented by the specified handle.</summary>

<returns>A <see cref="T:System.Reflection.FieldInfo" /> object representing the field specified by <paramref name="handle" />.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

Handles are valid only in the application domain in which they were obtained.

## Examples

The following code example uses the <xref:System.Type.GetFields%2A?displayProperty=nameWithType> method to get <xref:System.Reflection.FieldInfo> objects for the fields of a type, gets a <xref:System.RuntimeFieldHandle> structure for each field, and then retrieves the <xref:System.Reflection.FieldInfo> objects from the handles using this overload of the <xref:System.Reflection.FieldInfo.GetFieldFromHandle%2A> method.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/GetFieldFromHandle/fieldinfo_getfieldfromhandle.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/GetFieldFromHandle/fieldinfo_getfieldfromhandle.vb" id="Snippet1":::

]]></format>

</remarks>

<paramref name="handle" /> is invalid.</exception>

</Docs>

</Member>

<MemberSignature Language="F#" Value="static member GetFieldFromHandle : RuntimeFieldHandle * RuntimeTypeHandle -> System.Reflection.FieldInfo" Usage="System.Reflection.FieldInfo.GetFieldFromHandle (handle, declaringType)" />

<MemberType>Method</MemberType>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AttributeName Language="C#">[System.Runtime.InteropServices.ComVisible(false)]</AttributeName>

</Attribute>

<AttributeName Language="C#">[System.Security.SecuritySafeCritical]</AttributeName>

</Attribute>

</Attributes>

<ReturnType>System.Reflection.FieldInfo</ReturnType>

</ReturnValue>

</Parameters>

<Docs>

<param name="handle">A <see cref="T:System.RuntimeFieldHandle" /> structure that contains the handle to the internal metadata representation of a field.</param>

<param name="declaringType">A <see cref="T:System.RuntimeTypeHandle" /> structure that contains the handle to the generic type that defines the field.</param>

<summary>Gets a <see cref="T:System.Reflection.FieldInfo" /> for the field represented by the specified handle, for the specified generic type.</summary>

<returns>A <see cref="T:System.Reflection.FieldInfo" /> object representing the field specified by <paramref name="handle" />, in the generic type specified by <paramref name="declaringType" />.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

Handles are valid only in the application domain in which they were obtained.

The recommended practice is that `declaringType` should always be the runtime type handle of the constructed type that `handle` belongs to. That is, if `handle` is a runtime field handle for a field that belongs to `MyType<int>` (`MyType(Of Integer)` in Visual Basic), `declaringType` is the runtime type handle for `MyType<int>`. Do not use the runtime type handle of the generic type definition, unless the runtime field handle represents a field on the generic type definition.

Implementations are compatible in some cases. For example, a single implementation is shared by all types that are constructed from a particular generic type definition by using reference types for the generic type arguments. For example, `MyType<string>`, `MyType<object>`, and `MyType<ArrayList>` all share the same implementation. In this situation, the <xref:System.Reflection.FieldInfo> object that is returned represents a field on the type that `declaringType` specifies, regardless of the original source of `handle`. This practice is not recommended, because it works only if the generic type arguments of the constructed type are reference types.

If a generic argument is a value type, the runtime type handle of the constructed type is not compatible with runtime field handles from constructions that have a reference type in the same generic parameter position, or that have a different value type in that position. In that case, the only way to use the <xref:System.Reflection.FieldInfo.GetFieldFromHandle%28System.RuntimeFieldHandle%2CSystem.RuntimeTypeHandle%29?displayProperty=nameWithType> overload is to ensure that `declaringType` is the runtime type handle for the constructed type that `handle` belongs to.

## Examples

The following example shows how to retrieve <xref:System.Reflection.FieldInfo> objects for fields on constructed generic classes. The example defines the generic type `Test<T>` (`Test(Of T)` in Visual Basic) with a single field named `TestField`, of type `T`. The example gets the <xref:System.RuntimeFieldHandle> and <xref:System.RuntimeTypeHandle> for the case where `T` is <xref:System.String>, and demonstrates the following:

- An exception is thrown if the <xref:System.Reflection.FieldInfo.GetFieldFromHandle%28System.RuntimeFieldHandle%29> method overload is used. This is true even if the field is not of type `T`.

- A <xref:System.Reflection.FieldInfo> is retrieved successfully if the runtime type handle is from the same construction as the runtime field handle, in this case `Test<string>`.

- If the runtime type handle is from a compatible construction, in this case `Test<object>`, a <xref:System.Reflection.FieldInfo> for the field on the compatible construction is retrieved.

- If the runtime type handle is not from a compatible construction, an exception is thrown. In this case, a value type is specified for `T`.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/GetFieldFromHandle/source.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/GetFieldFromHandle/source.vb" id="Snippet1":::

]]></format>

</remarks>

<paramref name="handle" /> is invalid.

-or-

<paramref name="declaringType" /> is not compatible with <paramref name="handle" />. For example, <paramref name="declaringType" /> is the runtime type handle of the generic type definition, and <paramref name="handle" /> comes from a constructed type.</exception>

</Docs>

</Member>

<MemberSignature Language="F#" Value="override this.GetHashCode : unit -> int" Usage="fieldInfo.GetHashCode " />

<MemberType>Method</MemberType>

</Implements>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Int32</ReturnType>

</ReturnValue>

<Docs>

<summary>Returns the hash code for this instance.</summary>

<returns>A 32-bit signed integer hash code.</returns>

<remarks>To be added.</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="abstract member GetModifiedFieldType : unit -> Type
override this.GetModifiedFieldType : unit -> Type" Usage="fieldInfo.GetModifiedFieldType " />

<MemberType>Method</MemberType>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Type</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets the modified type of this field object.</summary>

<returns>A modified type.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

A modified type supports <xref:System.Type.GetOptionalCustomModifiers%2A>, <xref:System.Type.GetRequiredCustomModifiers%2A>, and <xref:System.Type.GetFunctionPointerCallingConventions%2A>, which are used to obtain custom modifiers from a function pointer.

To obtain the normal, unmodified type from a modified type, use <xref:System.Type.UnderlyingSystemType%2A>.

This method is provided for designers of managed compilers. For more information on custom modifiers, see classes in the <xref:System.Runtime.CompilerServices> namespace. Also see the metadata specification in Partition II of the [Common Language Infrastructure (CLI) documentation](https://www.ecma-international.org/publications-and-standards/standards/ecma-335/).

]]></format>

</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="abstract member GetOptionalCustomModifiers : unit -> Type[]
override this.GetOptionalCustomModifiers : unit -> Type[]" Usage="fieldInfo.GetOptionalCustomModifiers " />

<MemberSignature Language="C++ CLI" Value="public:
 virtual cli::array <Type ^> ^ GetOptionalCustomModifiers();" />

<MemberType>Method</MemberType>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Type[]</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets an array of types that identify the optional custom modifiers of the field.</summary>

<returns>An array of <see cref="T:System.Type" /> objects that identify the optional custom modifiers of the current field, such as <see cref="T:System.Runtime.CompilerServices.IsConst" />.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

The <xref:System.Reflection.FieldInfo.GetOptionalCustomModifiers%2A> and <xref:System.Reflection.FieldInfo.GetRequiredCustomModifiers%2A> methods are provided for designers of managed compilers. For more information on custom modifiers, see <xref:System.Runtime.CompilerServices.IsBoxed> and related classes in the <xref:System.Runtime.CompilerServices> namespace. Also see the metadata specification in Partition II of the [Common Language Infrastructure (CLI) documentation](https://www.ecma-international.org/publications-and-standards/standards/ecma-335/).

]]></format>

</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="abstract member GetRawConstantValue : unit -> obj
override this.GetRawConstantValue : unit -> obj" Usage="fieldInfo.GetRawConstantValue " />

<MemberType>Method</MemberType>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Object</ReturnType>

</ReturnValue>

<Docs>

<summary>Returns a literal value associated with the field by a compiler.</summary>

<returns>An <see cref="T:System.Object" /> that contains the literal value associated with the field. If the literal value is a class type with an element value of zero, the return value is <see langword="null" />.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

This method is provided for designers of managed compilers and code analyzers.

This method can be used in both the execution context and the reflection-only context.

In unmanaged metadata, the Constant table is used to store constant values for fields, parameters, and properties. Constant information does not directly influence runtime behavior. Compilers inspect this information, at compile time, when importing metadata. If used, the value of a constant is embedded in the Microsoft intermediate language (MSIL) stream the compiler emits. There are no MSIL instructions that can be used to access the Constant table at run time.

> [!NOTE]

> For more information on constant values and the Constant table, see Partition II of the [Common Language Infrastructure (CLI) documentation](https://www.ecma-international.org/publications-and-standards/standards/ecma-335/).

]]></format>

</remarks>

<exception cref="T:System.InvalidOperationException">The Constant table in unmanaged metadata does not contain a constant value for the current field.</exception>

<exception cref="T:System.FormatException">The type of the value is not one of the types permitted by the Common Language Specification (CLS). See the ECMA Partition II specification Metadata Logical Format: Other Structures, Element Types used in Signatures.</exception>

<exception cref="T:System.NotSupportedException">The constant value for the field is not set.</exception>

</Docs>

</Member>

<MemberSignature Language="F#" Value="abstract member GetRequiredCustomModifiers : unit -> Type[]
override this.GetRequiredCustomModifiers : unit -> Type[]" Usage="fieldInfo.GetRequiredCustomModifiers " />

<MemberSignature Language="C++ CLI" Value="public:
 virtual cli::array <Type ^> ^ GetRequiredCustomModifiers();" />

<MemberType>Method</MemberType>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Type[]</ReturnType>

</ReturnValue>

<Docs>

<summary>Gets an array of types that identify the required custom modifiers of the property.</summary>

<returns>An array of <see cref="T:System.Type" /> objects that identify the required custom modifiers of the current property, such as <see cref="T:System.Runtime.CompilerServices.IsConst" /> or <see cref="T:System.Runtime.CompilerServices.IsImplicitlyDereferenced" />.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

]]></format>

</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="override this.GetType : unit -> Type" Usage="fieldInfo.GetType " />

<MemberType>Method</MemberType>

<InterfaceMember>M:System.Runtime.InteropServices._FieldInfo.GetType</InterfaceMember>

</Implements>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Type</ReturnType>

</ReturnValue>

<Docs>

<summary>Discovers the attributes of a class field and provides access to field metadata.</summary>

<returns>To be added.</returns>

<remarks>To be added.</remarks>

</Docs>

</Member>

<MemberSignature Language="F#" Value="abstract member GetValue : obj -> obj" Usage="fieldInfo.GetValue obj" />

<MemberType>Method</MemberType>

<InterfaceMember FrameworkAlternate="netframework-1.1;netframework-2.0;netframework-3.0;netframework-3.5;netframework-4.0;netframework-4.5;netframework-4.5.1;netframework-4.5.2;netframework-4.6;netframework-4.6.1;netframework-4.6.2;netframework-4.7;netframework-4.7.1;netframework-4.7.2;netframework-4.8;netframework-4.8.1">M:System.Runtime.InteropServices._FieldInfo.GetValue(System.Object)</InterfaceMember>

</Implements>

<AssemblyName>System.Reflection</AssemblyName>

</AssemblyInfo>

<AssemblyName>mscorlib</AssemblyName>

</AssemblyInfo>

<AssemblyName>netstandard</AssemblyName>

</AssemblyInfo>

<AssemblyName>System.Runtime</AssemblyName>

</AssemblyInfo>

<ReturnType>System.Object</ReturnType>

</ReturnValue>

</Parameters>

<Docs>

<param name="obj">The object whose field value will be returned.</param>

<summary>When overridden in a derived class, returns the value of a field supported by a given object.</summary>

<returns>An object containing the value of the field reflected by this instance.</returns>

<format type="text/markdown"><![CDATA[

## Remarks

If the field is static, `obj` is ignored. For non-static fields, `obj` should be an instance of a class that inherits or declares the field. Note that the return type of `GetValue` is `Object`. For example, if the field holds a Boolean primitive value, an instance of `Object` with the appropriate Boolean value is returned. Before returning the value, `GetValue` checks to see if the user has access permission.

> [!NOTE]

> Access restrictions are ignored for fully trusted code. That is, private constructors, methods, fields, and properties can be accessed and invoked through reflection whenever the code is fully trusted.

> [!NOTE]

> This method can be used to access non-public members if the caller has been granted <xref:System.Security.Permissions.ReflectionPermission> with the <xref:System.Security.Permissions.ReflectionPermissionFlag.RestrictedMemberAccess?displayProperty=nameWithType> flag and if the grant set of the non-public members is restricted to the caller's grant set, or a subset thereof. (See [Security Considerations for Reflection](/dotnet/framework/reflection-and-codedom/security-considerations-for-reflection).)

> To use this functionality, your application should target .NET Framework 3.5 or later.

## Examples

The following example uses the <xref:System.Reflection.FieldInfo.GetValue%2A> method to retrieve the value of a static field. Note that the value of the `obj` argument is `null`.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/GetValue/getfldval.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/GetValue/getfldval.vb" id="Snippet1":::

The following example retrieves an array of <xref:System.Reflection.FieldInfo> objects that represents the fields of the `FieldsClass` type, and then calls the <xref:System.Reflection.FieldInfo.GetValue%2A> to display the value of each field for the `fieldsInst` object.

:::code language="csharp" source="~/snippets/csharp/System.Reflection/FieldInfo/GetValue/fieldinfo_getvalue.cs" id="Snippet1":::

:::code language="vb" source="~/snippets/visualbasic/System.Reflection/FieldInfo/GetValue/fieldinfo_getvalue.vb" id="Snippet1":::

]]></format>

</remarks>

<exception cref="T:System.Reflection.TargetException">The field is non-static and <paramref name="obj" /> is <see langword="null" />.

Note: In <see href="https://go.microsoft.com/fwlink/?LinkID=247912">.NET for Windows Store apps</see> or the <see href="https://learn.microsoft.com/dotnet/standard/cross-platform/cross-platform-development-with-the-portable-class-library">Portable Class Library</see>, catch <see cref="T:System.Exception" /> instead.</exception>

<exception cref="T:System.NotSupportedException">A field is marked literal, but the field does not have one of the accepted literal types.</exception>

<exception cref="T:System.FieldAccessException">The caller does not have permission to access this field.

Note: In <see href="https://go.microsoft.com/fwlink/?LinkID=247912">.NET for Windows Store apps</see> or the <see href="https://learn.microsoft.com/dotnet/standard/cross-platform/cross-platform-development-with-the-portable-class-library">Portable Class Library</see>, catch the base class exception, <see cref="T:System.MemberAccessException" />, instead.</exception>

<exception cref="T:System.ArgumentException">The method is neither declared nor inherited by the class of <paramref name="obj" />.</exception>

</Docs>

</Member>

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