ObjCRuntime Namespace

The ObjCRuntime namespace provides classes and attributes for binding Objective-C types to .NET.

Classes

Name	Description
AdoptsAttribute	An attribute used to specify that a class adopts a specific Objective-C protocol.
BaseWrapper	Base class used by the bindinge generator to generate Protocol Wrapper Types.
BindAsAttribute	The BindAsAttribute allows binding native NSNumber, NSValue and NSString (for enums) types into more accurate managed types.
BindingImplAttribute	This attribute provides information about binding code.
BlockCallbackAttribute	This attribute is applied to delegate parameters in a delegate to specify that the delegate parameter needs an Objective-C Block-style bridge.
BlockProxyAttribute	This attribute is used to notify the runtime which class is used to wrap Objective-C blocks into managed delegates.
CategoryAttribute	Attribute used to flag a class as a category that extends the API of another type.
CCallbackAttribute	This attribute is applied to delegate parameters in a delegate to specify that the delegate parameter needs an C-style bridge.
Class	Managed representation for an Objective-C class.
Constants	Global constants to system libraries.
DelegateProxyAttribute	This attribute is used to notify the runtime which class is used to wrap managed delegates into Objective-C blocks.
DesignatedInitializerAttribute	This attribute is used to mark managed constructors that bind Objective-C initializers marked with the NS_DESIGNATED_INITIALIZER attribute.
DisposableObject
Dlfcn	Provides access to the dynamic linker
LinkWithAttribute	A LinkWith attribute specifies how the native library associated with the assembly should be linked to the resulting application.
MarshalManagedExceptionEventArgs	The event args for the MarshalManagedException event.
MarshalObjectiveCExceptionEventArgs	The event args for the MarshalObjectiveCException event.
MonoNativeFunctionWrapperAttribute	Attribute to apply to delegates to flag them as targets that can be used with GetDelegateForFunctionPointer(IntPtr, Type).
MonoPInvokeCallbackAttribute	Attribute used to annotate functions that will be called back from the unmanaged world.
NativeAttribute	This attributes tells the Xamarin.iOS runtime that the native enum this managed enum binds is using a native size for the platform as the size for each enum value (i.e. a 32-bit value on 32-bit architectures, and a 64-bit value on 64-bit architectures).
NativeNameAttribute
NativeObjectExtensions
NMath
ObjCException
Protocol	Representation of an Objective-C protocol.
ReleaseAttribute	This attribute indicates that the return value of a function is retained (the caller obtains a reference to the object returned).
RequiresSuperAttribute	This attribute is applied to methods that must call their base implementation when they're overridden.
Runtime	Provides information about the Xamarin.iOS Runtime.
Runtime.ClassHandles
RuntimeException	Class that represents an exception that occurs in the Xamarin runtime.
Selector	Represents an Objective-C selector in managed code.
ThreadSafeAttribute	A Attribute that indicates that a UIKit (for iOS) or AppKit (for macOS) method or class is thread-safe.
ThrowHelper
TrampolineBlockBase
TransientAttribute	Flags a paramter in an NSObject subclass as being transient.
TypeConverter	Converts Obj-C type encodings to managed types.
UserDelegateTypeAttribute	This attribute is used on delegates created by the binding generator to properly map between signatures for Objective-C blocks and their corresponding exposed managed delegates. When binding Objective-C blocks, the binding generator will create a managed delegate whose signature is equivalent to the corresponding block's signature for the required binding code. However, this signature isn't necessarily accurate enough to re-create the block's signature at runtime (which is needed in some circumstances). This attribute makes it possible to find the type of the corresponding managed delegate that is exposed by the generated bindings, which does have enough information to re-create the corresponding block's signature.

Structs

Name	Description
BlockLiteral	Wraps a ECMA CLI delegate (C# lambdas, anonymous methods or delegates) as an Objective-C block.
NativeHandle

Interfaces

Name	Description
INativeObject	A simple interface that is used to expose the unmanaged object pointer in various classes in Xamarin.iOS.

Enums

Name	Description
Arch	Used to represent the host on which this app is running.
ArgumentSemantic	Represents the assignment semantics for properties.
BindingImplOptions	This enum is used by the BindingImplAttribute type to provide information about binding code.
Dlfcn.Mode
Dlfcn.RTLD	Dynamic loader resolution flags.
DlsymOption	Used to specify if a library requires using dlsym to resolve P/Invokes to native functions.
LinkTarget	Link targets available for LinkWithAttribute
MarshalManagedExceptionMode	This enum is used to specify what to do when an managed exception is thrown, and that exception reaches native code.
MarshalObjectiveCExceptionMode	This enum is used to specify what to do when an Objective-C exception is thrown, and that exception reaches managed code.

Delegates

Name	Description
MarshalManagedExceptionHandler	The event delegate for the MarshalManagedException event.
MarshalObjectiveCExceptionHandler	The event delegate for the MarshalObjectiveCException event.

Remarks

The ObjCRuntime namespace contains the fundamental types and attributes used to create bindings between Objective-C libraries and .NET code. It provides the runtime infrastructure that enables interoperability between managed .NET code and native Objective-C code on Apple platforms.

Key components of this namespace include:

• Binding attributes such as BindAsAttribute, CategoryAttribute, and DesignatedInitializerAttribute that control how .NET types map to Objective-C types. :
• Runtime support classes like Class and Selector that provide low-level access to the Objective-C runtime. :
• Block interoperability types such as BlockLiteral that enable working with Objective-C blocks from .NET. :

This namespace is primarily used by library authors creating bindings to Objective-C frameworks, though application developers may occasionally need to use some of its members for advanced interoperability scenarios.