Convert.ChangeType Method (Object, TypeCode)


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Returns an object of the specified type whose value is equivalent to the specified object.

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

public static object ChangeType(
	object value,
	TypeCode typeCode


Type: System.Object

An object that implements the IConvertible interface.

Type: System.TypeCode

The type of object to return.

Return Value

Type: System.Object

An object whose underlying type is typeCode and whose value is equivalent to value.


A null reference (Nothing in Visual Basic), if value is null and typeCode is Empty, String, or Object.

Exception Condition

This conversion is not supported.


value is null and typeCode specifies a value type.


value does not implement the IConvertible interface.


value is not in a format recognized by the typeCode type.


value represents a number that is out of the range of the typeCode type.


typeCode is invalid.

ChangeType(Object, TypeCode) is a general-purpose conversion method that converts the object specified by value to a predefined type specified by typeCode. The value parameter can be an object of any type. For the conversion to succeed, value must implement the IConvertible interface, because the method simply wraps a call to an appropriate IConvertible method. The method also requires that conversion of value to typeCode be supported.

The ChangeType(Object, TypeCode) method does not support the conversion of value to a custom type. To perform such a conversion, call the ChangeType(Object, Type) method.

The following example illustrates how to use the ChangeType(Object, TypeCode) method to change an Object to the type specified by the TypeCode parameter, if possible.

using System;

public class ChangeTypeTest {
    public static void Main() {

        Double d = -2.345;
        int i = (int)Convert.ChangeType(d, TypeCode.Int32);

        Console.WriteLine("The Double {0} when converted to an Int32 is {1}", d, i);

        string s = "12/12/2009";
        DateTime dt = (DateTime)Convert.ChangeType(s, typeof(DateTime));

        Console.WriteLine("The String {0} when converted to a Date is {1}", s, dt);        
// The example displays the following output:
//    The Double -2.345 when converted to an Int32 is -2
//    The String 12/12/2009 when converted to a Date is 12/12/2009 12:00:00 AM

.NET Framework
Available since 1.1
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