MissingFieldException Class

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Source:

MissingFieldException.cs

The exception that is thrown when there is an attempt to dynamically access a field that does not exist. If a field in a class library has been removed or renamed, recompile any assemblies that reference that library.

public ref class MissingFieldException : MissingMemberException

public class MissingFieldException : MissingMemberException

type MissingFieldException = class
    inherit MissingMemberException

Public Class MissingFieldException
Inherits MissingMemberException

Inheritance

Object

Exception

SystemException

MemberAccessException

MissingMemberException

MissingFieldException

Examples

This example shows what happens if you attempt to use reflection to call a method that does not exist and access a field that does not exist. The application recovers by catching the MissingMethodException, MissingFieldException, and MissingMemberException.

using namespace System;
using namespace System::Reflection;

ref class App
{
};

int main()
{
    try
    {
        // Attempt to call a static DoSomething method defined in the App class.
        // However, because the App class does not define this method,
        // a MissingMethodException is thrown.
        App::typeid->InvokeMember("DoSomething", BindingFlags::Static |
            BindingFlags::InvokeMethod, nullptr, nullptr, nullptr);
    }
    catch (MissingMethodException^ ex)
    {
        // Show the user that the DoSomething method cannot be called.
        Console::WriteLine("Unable to call the DoSomething method: {0}",
            ex->Message);
    }

    try
    {
        // Attempt to access a static AField field defined in the App class.
        // However, because the App class does not define this field,
        // a MissingFieldException is thrown.
        App::typeid->InvokeMember("AField", BindingFlags::Static |
            BindingFlags::SetField, nullptr, nullptr, gcnew array<Object^>{5});
    }
    catch (MissingFieldException^ ex)
    {
        // Show the user that the AField field cannot be accessed.
        Console::WriteLine("Unable to access the AField field: {0}",
            ex->Message);
    }

    try
    {
        // Attempt to access a static AnotherField field defined in the App class.
        // However, because the App class does not define this field,
        // a MissingFieldException is thrown.
        App::typeid->InvokeMember("AnotherField", BindingFlags::Static |
            BindingFlags::GetField, nullptr, nullptr, nullptr);
    }
    catch (MissingMemberException^ ex)
    {
        // Notice that this code is catching MissingMemberException which is the
        // base class of MissingMethodException and MissingFieldException.
        // Show the user that the AnotherField field cannot be accessed.
        Console::WriteLine("Unable to access the AnotherField field: {0}",
            ex->Message);
    }
}
// This code produces the following output.
//
// Unable to call the DoSomething method: Method 'App.DoSomething' not found.
// Unable to access the AField field: Field 'App.AField' not found.
// Unable to access the AnotherField field: Field 'App.AnotherField' not found.

using System;
using System.Reflection;

public class App
{
    public static void Main()
    {

        try
        {
            // Attempt to call a static DoSomething method defined in the App class.
            // However, because the App class does not define this method,
            // a MissingMethodException is thrown.
            typeof(App).InvokeMember("DoSomething", BindingFlags.Static |
                BindingFlags.InvokeMethod, null, null, null);
        }
        catch (MissingMethodException e)
        {
            // Show the user that the DoSomething method cannot be called.
            Console.WriteLine("Unable to call the DoSomething method: {0}", e.Message);
        }

        try
        {
            // Attempt to access a static AField field defined in the App class.
            // However, because the App class does not define this field,
            // a MissingFieldException is thrown.
            typeof(App).InvokeMember("AField", BindingFlags.Static | BindingFlags.SetField,
                null, null, new Object[] { 5 });
        }
        catch (MissingFieldException e)
        {
         // Show the user that the AField field cannot be accessed.
         Console.WriteLine("Unable to access the AField field: {0}", e.Message);
        }

        try
        {
            // Attempt to access a static AnotherField field defined in the App class.
            // However, because the App class does not define this field,
            // a MissingFieldException is thrown.
            typeof(App).InvokeMember("AnotherField", BindingFlags.Static |
                BindingFlags.GetField, null, null, null);
        }
        catch (MissingMemberException e)
        {
         // Notice that this code is catching MissingMemberException which is the
         // base class of MissingMethodException and MissingFieldException.
         // Show the user that the AnotherField field cannot be accessed.
         Console.WriteLine("Unable to access the AnotherField field: {0}", e.Message);
        }
    }
}
// This code example produces the following output:
//
// Unable to call the DoSomething method: Method 'App.DoSomething' not found.
// Unable to access the AField field: Field 'App.AField' not found.
// Unable to access the AnotherField field: Field 'App.AnotherField' not found.

open System
open System.Reflection

type App = class end

try
    // Attempt to call a static DoSomething method defined in the App class.
    // However, because the App class does not define this method,
    // a MissingMethodException is thrown.
    typeof<App>.InvokeMember("DoSomething", BindingFlags.Static ||| BindingFlags.InvokeMethod, null, null, null)
    |> ignore
with :? MissingMethodException as e ->
    // Show the user that the DoSomething method cannot be called.
    printfn $"Unable to call the DoSomething method: {e.Message}"

try
    // Attempt to access a static AField field defined in the App class.
    // However, because the App class does not define this field,
    // a MissingFieldException is thrown.
    typeof<App>.InvokeMember("AField", BindingFlags.Static ||| BindingFlags.SetField, null, null, [| box 5 |])
    |> ignore
with :? MissingFieldException as e ->
    // Show the user that the AField field cannot be accessed.
    printfn $"Unable to access the AField field: {e.Message}"

try
    // Attempt to access a static AnotherField field defined in the App class.
    // However, because the App class does not define this field,
    // a MissingFieldException is thrown.
    typeof<App>.InvokeMember("AnotherField", BindingFlags.Static ||| BindingFlags.GetField, null, null, null)
    |> ignore
with :? MissingMemberException as e ->
    // Notice that this code is catching MissingMemberException which is the
    // base class of MissingMethodException and MissingFieldException.
    // Show the user that the AnotherField field cannot be accessed.
    printfn $"Unable to access the AnotherField field: {e.Message}"
// This code example produces the following output:
//     Unable to call the DoSomething method: Method 'App.DoSomething' not found.
//     Unable to access the AField field: Field 'App.AField' not found.
//     Unable to access the AnotherField field: Field 'App.AnotherField' not found.

Imports System.Reflection

Public Class App
    Public Shared Sub Main() 
        Try
            ' Attempt to call a static DoSomething method defined in the App class.
            ' However, because the App class does not define this method, 
            ' a MissingMethodException is thrown.
            GetType(App).InvokeMember("DoSomething", BindingFlags.Static Or BindingFlags.InvokeMethod, _
                                       Nothing, Nothing, Nothing)
        Catch e As MissingMethodException
            ' Show the user that the DoSomething method cannot be called.
            Console.WriteLine("Unable to call the DoSomething method: {0}", e.Message)
        End Try
        Try
            ' Attempt to access a static AField field defined in the App class.
            ' However, because the App class does not define this field, 
            ' a MissingFieldException is thrown.
            GetType(App).InvokeMember("AField", BindingFlags.Static Or BindingFlags.SetField, _
                                       Nothing, Nothing, New [Object]() {5})
        Catch e As MissingFieldException
            ' Show the user that the AField field cannot be accessed.
            Console.WriteLine("Unable to access the AField field: {0}", e.Message)
        End Try
        Try
            ' Attempt to access a static AnotherField field defined in the App class.
            ' However, because the App class does not define this field, 
            ' a MissingFieldException is thrown.
            GetType(App).InvokeMember("AnotherField", BindingFlags.Static Or BindingFlags.GetField, _
                                       Nothing, Nothing, Nothing)
        Catch e As MissingMemberException
            ' Notice that this code is catching MissingMemberException which is the  
            ' base class of MissingMethodException and MissingFieldException.
            ' Show the user that the AnotherField field cannot be accessed.
            Console.WriteLine("Unable to access the AnotherField field: {0}", e.Message)
        End Try
    End Sub 
End Class 
' This code example produces the following output:
'
' Unable to call the DoSomething method: Method 'App.DoSomething' not found.
' Unable to access the AField field: Field 'App.AField' not found.
' Unable to access the AnotherField field: Field 'App.AnotherField' not found.

Remarks

Normally a compilation error is generated if code attempts to access a nonexistent member of a class. MissingFieldException is designed to handle cases where an attempt is made to dynamically access a renamed or deleted field of an assembly that is not referenced by its strong name. The MissingFieldException is thrown when code in a dependent assembly attempts to access a missing field in an assembly that was modified.

MissingFieldException uses the HRESULT COR_E_MISSINGFIELD, that has the value 0x80131511.

For a list of initial property values for an instance of MissingFieldException, see the MissingFieldException constructors.

Constructors

MissingFieldException()	Initializes a new instance of the MissingFieldException class.
MissingFieldException(SerializationInfo, StreamingContext)	Obsolete. Initializes a new instance of the MissingFieldException class with serialized data.
MissingFieldException(String, Exception)	Initializes a new instance of the MissingFieldException class with a specified error message and a reference to the inner exception that is the cause of this exception.
MissingFieldException(String, String)	Initializes a new instance of the MissingFieldException class with the specified class name and field name.
MissingFieldException(String)	Initializes a new instance of the MissingFieldException class with a specified error message.

Fields

ClassName	Holds the class name of the missing member. (Inherited from MissingMemberException)
MemberName	Holds the name of the missing member. (Inherited from MissingMemberException)
Signature	Holds the signature of the missing member. (Inherited from MissingMemberException)

Properties

Data	Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception)
HelpLink	Gets or sets a link to the help file associated with this exception. (Inherited from Exception)
HResult	Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception)
InnerException	Gets the Exception instance that caused the current exception. (Inherited from Exception)
Message	Gets the text string showing the signature of the missing field, the class name, and the field name. This property is read-only.
Source	Gets or sets the name of the application or the object that causes the error. (Inherited from Exception)
StackTrace	Gets a string representation of the immediate frames on the call stack. (Inherited from Exception)
TargetSite	Gets the method that throws the current exception. (Inherited from Exception)

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetBaseException()	When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)	Obsolete. Sets the SerializationInfo object with the class name, the member name, the signature of the missing member, and additional exception information. (Inherited from MissingMemberException)
GetType()	Gets the runtime type of the current instance. (Inherited from Exception)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Creates and returns a string representation of the current exception. (Inherited from Exception)

Events

SerializeObjectState

Obsolete. Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception)

See also

• Exception
• Handling and Throwing Exceptions