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Type.GetType Method (String, Boolean)

Gets the Type with the specified name, performing a case-sensitive search and specifying whether to throw an exception if the type is not found.

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

public static Type GetType (
	string typeName,
	bool throwOnError
)
public static Type GetType (
	String typeName, 
	boolean throwOnError
)
public static function GetType (
	typeName : String, 
	throwOnError : boolean
) : Type

Parameters

typeName

The name of the AssemblyQualifiedName to get.

throwOnError

true to throw an exception if the type cannot be found; false to return a null reference (Nothing in Visual Basic).

Return Value

The Type with the specified name, if found; otherwise, a null reference (Nothing in Visual Basic).

Exception typeCondition

ArgumentNullException

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

TargetInvocationException

A class initializer is invoked and throws an exception.

TypeLoadException

throwOnError is true and the type is not found.

-or-

typeName represents an array of TypedReference. This is a change from the behavior in the .NET Framework versions 1.0 and 1.1, which was to return a null reference.

ArgumentException

typeName is invalid, for example if it contains invalid characters, or if it is a zero-length string.

GetType only works on assemblies loaded from disk. If you call GetType to look up a type defined in a dynamic assembly defined using the System.Reflection.Emit services, you might get inconsistent behavior. The behavior depends on whether the dynamic assembly is persistent, that is, created using the RunAndSave or Save access modes of the System.Reflection.Emit.AssemblyBuilderAccess enumeration. If the dynamic assembly is persistent and has been written to disk before GetType is called, the loader finds the saved assembly on disk, loads that assembly, and retrieves the type from that assembly. If the assembly has not been saved to disk when GetType is called, the method returns a null reference (Nothing in Visual Basic). GetType does not understand transient dynamic assemblies; therefore, calling GetType to retrieve a type in a transient dynamic assembly returns a null reference (Nothing in Visual Basic).

To use GetType on a dynamic module, subscribe to the AppDomain.AssemblyResolve event and call GetType before saving. Otherwise, you will get two copies of the assembly in memory.

The throwOnError parameter only affects what happens when the type is not found. It does not affect any other exceptions that might be thrown. In particular, if the type is found but cannot be loaded, a TypeLoadException can be thrown even if throwOnError is false.

If the requested type 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).

The following table shows what members of a base class are returned by the Get methods when reflecting on a type.

Member Type

Static

Non-Static

Constructor

No

No

Field

No

Yes. A field is always hide-by-name-and-signature.

Event

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

Method

No

Yes. A method (both virtual and non-virtual) can be hide-by-name or hide-by-name-and-signature.

Nested Type

No

No

Property

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

  1. Hide-by-name-and-signature considers all of the parts of the signature, including custom modifiers, return types, parameter types, sentinels, and unmanaged calling conventions. This is a binary comparison.

  2. For reflection, properties and events are hide-by-name-and-signature. If you have a property with both a get and a set accessor in the base class, but the derived class has only a get accessor, the derived class property hides the base class property, and you will not be able to access the setter on the base class.

  3. Custom attributes are not part of the common type system.

Arrays or COM types are not searched for unless they have already been loaded into the table of available classes.

typeName can be a simple type name, a type name that includes a namespace, or a complex name that includes an assembly name specification.

If typeName includes only the name of the Type, this method searches in the calling object's assembly, then in the mscorlib.dll assembly. If typeName is fully qualified with the partial or complete assembly name, this method searches in the specified assembly.

AssemblyQualifiedName can return a fully qualified type name including nested types, the assembly name, and generic arguments. All compilers that support the common language runtime will emit the simple name of a nested class, and reflection constructs a mangled name when queried, in accordance with the following conventions.

Delimiter

Meaning

Backslash (\)

Escape character.

Comma (,)

Precedes the Assembly name.

Plus sign (+)

Precedes a nested class.

Period (.)

Denotes namespace identifiers.

Brackets ([])

Enclose a generic type argument list, for a constructed generic type; within a type argument list, enclose an assembly-qualified type.

For example, the fully qualified name for a class might look like this:

TopNamespace.SubNameSpace.ContainingClass+NestedClass,MyAssembly

If the namespace were TopNamespace.Sub+Namespace, then the string would have to precede the plus sign (+) with an escape character (\) to prevent it from being interpreted as a nesting separator. Reflection emits this string as follows:

TopNamespace.Sub\+Namespace.ContainingClass+NestedClass,MyAssembly

A "++" becomes "\+\+", and a "\" becomes "\\".

This qualified name can be persisted and later used to load the Type. To search for and load a Type, use GetType either with the type name only or with the assembly qualified type name. GetType with the type name only will look for the Type in the caller's assembly and then in the System assembly. GetType with the assembly qualified type name will look for the Type in any assembly.

Type names may include trailing characters that denote additional information about the type, such as whether the type is a reference type, a pointer type or an array type. To retrieve the type name without these trailing characters, use t.GetElementType().ToString(), where t is the type.

Spaces are relevant in all type name components except the assembly name. In the assembly name, spaces before the ',' separator are relevant, but spaces after the ',' separator are ignored.

For generic types, the type argument list is enclosed in brackets, and the type arguments are separated by commas. For example, a generic Dictionary has two type parameters. A Dictionary of MyType with keys of type String might be represented as follows:

System.Collections.Generic.Dictionary`2[System.String,MyType]

To specify an assembly-qualified type within a type argument list, enclose the assembly-qualified type within brackets. Otherwise, the commas that separate the parts of the assembly-qualified name are interpreted as delimiting additional type arguments. For example, a Dictionary of MyType from MyAssembly.dll, with keys of type String, might be specified as follows:

Type.GetType("System.Collections.Generic.Dictionary`2[System.String,[MyType,MyAssembly]]")
NoteNote

An assembly-qualified type can be enclosed in brackets only when it appears within a type parameter list. The rules for searching assemblies for qualified and unqualified types in type parameter lists are the same as the rules for qualified and unqualified nongeneric types.

The following table shows the syntax you use with GetType for various types.

To Get

Use

An unmanaged pointer to MyType

Type.GetType("MyType*")

An unmanaged pointer to a pointer to MyType

Type.GetType("MyType**")

A managed pointer or reference to MyType

Type.GetType("MyType&"). Note that unlike pointers, references are limited to one level.

A parent class and a nested class

Type.GetType("MyParentClass+MyNestedClass")

A one-dimensional array with a lower bound of 0

Type.GetType("MyArray[]")

A one-dimensional array with an unknown lower bound

Type.GetType("MyArray[*]")

An n-dimensional array

A comma (,) inside the brackets a total of n-1 times. For example, System.Object[,,] represents a three-dimensional Object array.

A two-dimensional array's array

Type.GetType("MyArray[][]")

A rectangular two-dimensional array with unknown lower bounds

Type.GetType("MyArray[*,*]") or Type.GetType("MyArray[,]")

A generic type with one type argument

Type.GetType("MyGenericType`1[MyType]")

A generic type with two type arguments

Type.GetType("MyGenericType`2[MyType,AnotherType]")

A generic type with two assembly-qualified type arguments

Type.GetType("MyGenericType`2[[MyType,MyAssembly],[AnotherType,AnotherAssembly]]")

An assembly-qualified generic type with an assembly-qualified type argument

Type.GetType("MyGenericType`1[[MyType,MyAssembly]],MyGenericTypeAssembly")

A generic type whose type argument is a generic type with two type arguments

Type.GetType("MyGenericType`1[AnotherGenericType`2[MyType,AnotherType]]")

The following example retrieves the type of System.Int32 and uses that type object to display the FullName property of System.Int32. If a type object refers to an assembly that does not exist, this example throws an exception.

using System;
namespace MyTypeNameSpace
{
    class MyClass
    {
        public static void Main(string[] arg)
        {
            try
            {
                // Get the type of a specified class.
                Type myType1 = Type.GetType("System.Int32");
                Console.WriteLine("The full name is {0}.", myType1.FullName);
                // Since NoneSuch does not exist in this assembly, GetType throws a TypeLoadException.
                Type myType2 = Type.GetType("NoneSuch", true);
                Console.WriteLine("The full name is {0}.", myType2.FullName);
            }
            catch(TypeLoadException e)
            {
                Console.WriteLine(e.Message);
            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}

package MyTypeNameSpace; 

import System.*;

class MyClass
{
    public static void main(String[] args)
    {
        try {
            // Get the type of a specified class.
            Type myType1 = Type.GetType("System.Int32");
            Console.WriteLine("The full name is {0}.", myType1.get_FullName());

            // Since NoneSuch does not exist in this assembly, GetType throws
            // a TypeLoadException.
            Type myType2 = Type.GetType("NoneSuch", true);
            Console.WriteLine("The full name is {0}.", myType2.get_FullName());
        }
        catch (TypeLoadException e) {
            Console.WriteLine(e.get_Message());
        }
        catch (System.Exception e) {
            Console.WriteLine(e.get_Message());
        }
    } //main
} //MyClass

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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