MethodBase.Invoke Method (Object, Object[])

public Object Invoke(
	Object obj,
	Object[] parameters
)

Return Value

Type: System.Object
An object containing the return value of the invoked method, or null in the case of a constructor.

Caution
Elements of the parameters array that represent parameters declared with the ref or out keyword may also be modified.

Implements

This is a convenience method that calls the Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) method overload, passing Default for invokeAttr and null for binder and culture.

If the invoked method throws an exception, the Exception.GetBaseException method returns the exception.

To invoke a static method using its MethodInfo object, pass null for obj.

Note
If this method overload is used to invoke an instance constructor, the object supplied for obj is reinitialized; that is, all instance initializers are executed. The return value is null. If a class constructor is invoked, the class is reinitialized; that is, all class initializers are executed. The return value is null.

Note

Starting with the .NET Framework version 2.0 Service Pack 1, this method can be used to access non-public members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess 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.) To use this functionality, your application should target the .NET Framework version 3.5 or later.

If a parameter of the current method is a value type, and the corresponding argument in parameters is null, the runtime passes a zero-initialized instance of the value type.

The following code example demonstrates dynamic method lookup using reflection. Note that you cannot use the MethodInfo object from the base class to invoke the overridden method in the derived class, because late binding cannot resolve overrides.

using System;
using System.Reflection;

public class MagicClass
{
    private int magicBaseValue;

    public MagicClass()
    {
        magicBaseValue = 9;
    }

    public int ItsMagic(int preMagic)
    {
        return preMagic * magicBaseValue;
    }
}

public class TestMethodInfo
{
    public static void Main()
    {
        // Get the constructor and create an instance of MagicClass

        Type magicType = Type.GetType("MagicClass");
        ConstructorInfo magicConstructor = magicType.GetConstructor(Type.EmptyTypes);
        object magicClassObject = magicConstructor.Invoke(new object[]{});

        // Get the ItsMagic method and invoke with a parameter value of 100

        MethodInfo magicMethod = magicType.GetMethod("ItsMagic");
        object magicValue = magicMethod.Invoke(magicClassObject, new object[]{100});

        Console.WriteLine("MethodInfo.Invoke() Example\n");
        Console.WriteLine("MagicClass.ItsMagic() returned: {0}", magicValue);
    }
}

// The example program gives the following output:
//
// MethodInfo.Invoke() Example
//
// MagicClass.ItsMagic() returned: 900

.NET Framework

.NET Framework Client Profile

Portable Class Library

• ReflectionPermission  

  for accessing non-public members when the grant set of the non-public members is restricted to the caller's grant set, or a subset thereof. Associated enumeration: ReflectionPermissionFlag.RestrictedMemberAccess

• ReflectionPermission  

  for accessing non-public members regardless of their grant set. Associated enumeration: ReflectionPermissionFlag.MemberAccess

• ReflectionPermission  

  when invoked late-bound through mechanisms such as Type.InvokeMember. Associated enumeration: ReflectionPermissionFlag.MemberAccess.

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference