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Type.GetProperty Method (String, Type, Type[], ParameterModifier[])

Searches for the specified public property whose parameters match the specified argument types and modifiers.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

public PropertyInfo GetProperty (
	string name,
	Type returnType,
	Type[] types,
	ParameterModifier[] modifiers
)
public final PropertyInfo GetProperty (
	String name, 
	Type returnType, 
	Type[] types, 
	ParameterModifier[] modifiers
)
public final function GetProperty (
	name : String, 
	returnType : Type, 
	types : Type[], 
	modifiers : ParameterModifier[]
) : PropertyInfo
Not applicable.

Parameters

name

The String containing the name of the public property to get.

returnType

The return type of the property.

types

An array of Type objects representing the number, order, and type of the parameters for the indexed property to get.

-or-

An empty array of the type Type (that is, Type[] types = new Type[0]) to get a property that is not indexed.

modifiers

An array of ParameterModifier objects representing the attributes associated with the corresponding element in the types array. The default binder does not process this parameter.

Return Value

A PropertyInfo object representing the public property that matches the specified requirements, if found; otherwise, a null reference (Nothing in Visual Basic).

Exception typeCondition

AmbiguousMatchException

More than one property is found with the specified name and matching the specified argument types and modifiers.

ArgumentNullException

name is a null reference (Nothing in Visual Basic).

-or-

types is a null reference (Nothing in Visual Basic).

ArgumentException

types is multidimensional.

-or-

modifiers is multidimensional.

-or-

types and modifiers do not have the same length.

NullReferenceException

An element of types is a null reference (Nothing in Visual Basic).

A property is considered public to reflection if it has at least one accessor that is public. Otherwise the property is considered private, and you must use BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static (in Visual Basic, combine the values using Or) to get it.

Although the default binder does not process ParameterModifier (the modifiers parameter), you can use the abstract System.Reflection.Binder class to write a custom binder that does process modifiers. ParameterModifier is only used when calling through COM interop, and only parameters that are passed by reference are handled.

The types array and the modifiers array have the same length. A parameter specified in the types array can have the following attributes, which are specified in the modifiers array: pdIn, pdOut, pdLcid, pdRetval, pdOptional, and pdHasDefault, which represent [In], [Out], [lcid], [retval], [optional], and a value specifying whether the parameter has a default value. A parameter's associated attributes are stored in the metadata and enhance interoperability.

The search for name is case-sensitive. The search includes public static and public instance properties.

If the requested property is non-public and the caller does not have ReflectionPermission to reflect non-public objects outside the current assembly, this method returns a null reference (Nothing in Visual Basic).

If the current Type represents a constructed generic type, this method returns the PropertyInfo with the type parameters replaced by the appropriate type arguments.

If the current Type represents a type parameter in the definition of a generic type or generic method, this method searches the properties of the class constraint.

Indexers and Default Properties

Visual Basic 2005, Visual C# 2005, and Visual C++ 2005 have simplified syntax for accessing indexed properties and allow one indexed property to be a default for its type. For example, if the variable myList refers to an ArrayList, the syntax myList[3] (myList(3) in Visual Basic) retrieves the element with the index of 3. You can overload the property.

In C#, this feature is called an indexer and cannot be refered to by name. By default, a C# indexer appears in metadata as an indexed property named "Item". However, a class library developer can use the IndexerNameAttribute attribute to change the name of the indexer in the metadata. For example, the String class has an indexer named Chars. Indexed properties created using languages other than C# can have names other than Item, as well. 

To determine whether a type has a default property, use the GetCustomAttributes method to test for the DefaultMemberAttribute attribute. If the type has DefaultMemberAttribute, the MemberName property returns the name of the default property.

The following example obtains a Type object corresponding to MyPropertyClass, and the indexed property of this class is retrieved using the arguments passed to the GetProperty method.

using System;
using System.Reflection;
public class MyPropertyClass
{
    private int [,] myPropertyArray = new int[10,10]; 
    // Declare an indexer.
    public int this [int i,int j]
    {
        get 
        {
            return myPropertyArray[i,j];
        }
        set 
        {
            myPropertyArray[i,j] = value;
        }
    }
}
public class MyTypeClass
{
    public static void Main()
    {
        try
        {
            Type myType=typeof(MyPropertyClass);
            Type[] myTypeArray = new Type[2];
            // Create an instance of the Type array representing the number, order 
            // and type of the parameters for the property.
            myTypeArray.SetValue(typeof(int),0);
            myTypeArray.SetValue(typeof(int),1);
            // Search for the indexed property whose parameters match the
            // specified argument types and modifiers.
            PropertyInfo myPropertyInfo = myType.GetProperty("Item",
                typeof(int),myTypeArray,null);
            Console.WriteLine(myType.FullName + "." + myPropertyInfo.Name + 
                " has a property type of " + myPropertyInfo.PropertyType);
         }
        catch(Exception ex)
        {
            Console.WriteLine("An exception occurred " + ex.Message);
        }
    }
}

import System.*;
import System.Reflection.*;

public class MyPropertyClass
{
    private int myPropertyArray[,] = new int[10, 10];

    // Declare an indexer.
    /** @property 
     */
    public int get_Item(int i, int j)
    {
        return myPropertyArray[i, j];
    } //Item 

    /** @property 
     */
    public void set_Item(int i, int j, int value)
    {
        myPropertyArray[i, j] = value;
    } //Item
} //MyPropertyClass

public class MyTypeClass
{
    public static void main(String[] args)
    {
        try {
            Type myType = MyPropertyClass.class.ToType();
            Type myTypeArray[] = new Type[2];
            // Create an instance of the Type array representing the number, 
            // order and type of the parameters for the property.
            myTypeArray.SetValue(int.class.ToType(), 0);
            myTypeArray.SetValue(int.class.ToType(), 1);
            // Search for the indexed property whose parameters match the
            // specified argument types and modifiers.
            PropertyInfo myPropertyInfo = myType.GetProperty("Item",
                int.class.ToType(), myTypeArray, null);
            Console.WriteLine(myType.get_FullName() + "." + myPropertyInfo.
                get_Name() + " has a property type of " + myPropertyInfo.
                GetType());
        }
        catch (System.Exception ex) {
            Console.WriteLine("An exception occurred " + ex.get_Message());
        }
    } //main
} //MyTypeClass

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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