IReflect.InvokeMember Method

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Invokes a specified member.

public:
 System::Object ^ InvokeMember(System::String ^ name, System::Reflection::BindingFlags invokeAttr, System::Reflection::Binder ^ binder, System::Object ^ target, cli::array <System::Object ^> ^ args, cli::array <System::Reflection::ParameterModifier> ^ modifiers, System::Globalization::CultureInfo ^ culture, cli::array <System::String ^> ^ namedParameters);

public object? InvokeMember (string name, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder? binder, object? target, object?[]? args, System.Reflection.ParameterModifier[]? modifiers, System.Globalization.CultureInfo? culture, string[]? namedParameters);

abstract member InvokeMember : string * System.Reflection.BindingFlags * System.Reflection.Binder * obj * obj[] * System.Reflection.ParameterModifier[] * System.Globalization.CultureInfo * string[] -> obj

Public Function InvokeMember (name As String, invokeAttr As BindingFlags, binder As Binder, target As Object, args As Object(), modifiers As ParameterModifier(), culture As CultureInfo, namedParameters As String()) As Object

Parameters

name

String

The name of the member to find.

invokeAttr

BindingFlags

One of the BindingFlags invocation attributes. The invokeAttr parameter may be a constructor, method, property, or field. A suitable invocation attribute must be specified. Invoke the default member of a class by passing the empty string ("") as the name of the member.

binder

Binder

One of the BindingFlags bit flags. Implements Binder, containing properties related to this method.

target

Object

The object on which to invoke the specified member. This parameter is ignored for static members.

args

Object[]

An array of objects that contains the number, order, and type of the parameters of the member to be invoked. This is an empty array if there are no parameters.

modifiers

ParameterModifier[]

An array of ParameterModifier objects. This array has the same length as the args parameter, representing the invoked member's argument attributes in the metadata. A parameter can have the following attributes: pdIn, pdOut, pdRetval, pdOptional, and pdHasDefault. These represent [In], [Out], [retval], [optional], and a default parameter, respectively. These attributes are used by various interoperability services.

culture

CultureInfo

An instance of CultureInfo used to govern the coercion of types. For example, culture converts a string that represents 1000 to a Double value, since 1000 is represented differently by different cultures. If this parameter is null, the CultureInfo for the current thread is used.

namedParameters

String[]

A string array of parameters.

Returns

Object

The specified member.

Exceptions

ArgumentException

More than one argument is specified for a field set.

MissingFieldException

The field or property cannot be found.

MissingMethodException

The method cannot be found.

SecurityException

A private member is invoked without the necessary ReflectionPermission.

Examples

The following example obtains the value of the Now property.

#using <System.DLL>

using namespace System;
using namespace System::Reflection;

#define NULL 0
void main()
{
   Type^ tDate = Type::GetType( L"System.DateTime" );
   Object^ result = tDate->InvokeMember( L"Now", BindingFlags::GetProperty, nullptr, NULL, gcnew array<Object^>(0) );
   Console::WriteLine( result->ToString() );
}

using System;
using System.Reflection;

public class MainClass
{
    public static void Main(string[] args)
    {
        Type tDate = typeof(System.DateTime);
        Object result = tDate.InvokeMember("Now",
            BindingFlags.GetProperty, null, null, new Object[0]);
        Console.WriteLine(result.ToString());
    }
}

Imports System.Reflection

Public Class MainClass
    Public Overloads Shared Sub Main(ByVal args() As String)
        Dim tDate As Type = GetType(System.DateTime)
        Dim result As [Object] = tDate.InvokeMember("Now", _
            BindingFlags.GetProperty, Nothing, Nothing, New [Object](-1) {})
        Console.WriteLine(result.ToString())
    End Sub
End Class

Remarks

The method that is to be invoked must be accessible and provide the most specific match with the specified argument list, under the constraints of the specified binder and invocation attributes.

A method is invoked if the number of parameters in the method declaration equals the number of arguments in the specified argument list, and the type of each argument can be converted by the binder to the type of the parameter.

Note

The array of parameter modifiers passed to the InvokeMember method must contain a single parameter modifier. Only the first parameter modifier is considered when determining which argument needs to be passed by reference when exposed to COM.

The binder finds all matching methods, in accordance with the type of binding requested (BindingFlags.InvokeMethod, GetProperties, and so on). The set of methods is filtered by the name, number of arguments, and a set of search modifiers defined in the binder. After the method is selected, it is invoked, and accessibility is checked at that point. The search may control which set of methods is searched based upon the accessibility attribute associated with the method. BindToMethod selects the method to be invoked. The default binder selects the most specific match.

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.

See also

• Object
• Binder
• BindingFlags