iOS Guides | Samples

CoreMidi Namespace

The CoreMidi namespace provides classes for interacting with the MIDI subsystem.


CoreMIDI is an API that talks to the MIDI server on iOS and OSX which in turn interacts with MIDI devices connected to your Mac or iOS device.

When using CoreMIDI, you will run into various classes that deal with different parts of the MIDI stack, the following graphic illustrates the relationships:

The MIDI device itself is represented by the MidiDevice class. Devices can contain one or more entities (MidiEntity). For example a MIDI device could contain two independent MIDI tone generators. Each Entity contains a series of endpoints which are either sources or destintions. Both MIDI sources and MIDI destinations are encapsulated by the MidiEntity class.

To start with MIDI, you will need to create a MidiClient object. This object is the gateway between your application and the MIDI server process. You subscribe to the events that this object raises to track devices being added, removed and to changes in their properties and setup configuration.

You also use the MidiClient to create input ports and output ports. The input ports raise the MidiPort.MessageReceived event when new MIDI data is available and you can use the MidiPacketsEventArgs.Packets property in the arguments received to get the data out

See the MidiClient class for an example of how to set things up.

To use networked MIDI connections, you need to enable the network session and set its connection policy, like this:

C# Example

var session = MidiNetworkSession.DefaultSession;
session.Enabled = true;
session.ConnectionPolicy = MidiNetworkConnectionPolicy.Anyone;

To connect to a remote MIDI network host you use the MidiNetworkHost, like this:

C# Example

var host = MidiNetworkHost.Create ("My Session", "", 5004);
var connection = MidiNetworkConnection.FromHost (host);


IOErrorEventArgsProvides data for the IOErrorEventArgs.IOError event.
MidiGlobal methods and constants for using CoreMidi.
Midi+NotificationsNotification posted by the Midi class.
MidiClientMain entry point to use MIDI in MacOS X and iOS.
MidiControlTransformRepresents a transformation of a MIDI control.
MidiDeviceRepresents a MIDI device (typically they represent a hardware device, but virtual devices also exist). Devices can contain one or more entities.
MidiEndpointEndpoints represent an individual source or destination on the MIDI stream.
MidiEntityA MidiObject that represents a sub-component of a MidiDevice.
MidiErrorErrors raised by the CoreMIDI stack.
MidiExceptionException raised by Midi methods.
MidiNetworkConnectionA connection to a MIDI network host, using a MidiNetworkSession.
MidiNetworkConnectionPolicyAn enumeration whose values specify which hosts are eligible to connect to a MIDI network session.
MidiNetworkHostA remote MIDI host.
MidiNetworkSessionA singleton class that maintains the MidiNetworkConnections between various MIDI entities.
MidiObjectBase class for the MidiClient, MidiPort, MidiEntity, MidiDevice and MidiEndpoint classes.
MidiPacketEncapsulates a series of MIDI events.
MidiPacketsEventArgsProvides data for the MidiPacketsEventArgs.MessageReceived and MidiPacketsEventArgs.MessageReceived events.
MidiPortInput and Output ports.
MidiThruConnectionManages MIDI play-through connections.
MidiThruConnectionEndpointSource or Destination of a MidiThruConnection.
MidiThruConnectionParamsMIDI transformations and routings.
MidiTransformObject that defines how a MIDI event is transformed.
MidiTransformControlTypeMIDI Control Transformation Type.
MidiTransformTypeMIDI transform types.
MidiValueMapMIDI Value map.
ObjectAddedOrRemovedEventArgsProvides data for the ObjectAddedOrRemovedEventArgs.ObjectAdded and ObjectAddedOrRemovedEventArgs.ObjectRemoved events.
ObjectPropertyChangedEventArgsProvides data for the ObjectPropertyChangedEventArgs.PropertyChanged event.