This topic pertains only to applications developed in C++.

In several places, DirectInput requires you to pass a version number to a method. This parameter specifies which version of DirectX the DirectInput subsystem should emulate.

Applications designed for the latest version of DirectInput should pass the value DIRECTINPUT_VERSION as defined in Dinput.h.

Applications designed to run under previous versions should pass a value corresponding to the version of DirectInput for which they were designed, with the main version number in the high-order byte. For example, an application that was designed to run on DirectInput 3 should pass a value of 0x0300.

If you define DIRECTINPUT_VERSION as 0x0300 before including the Dinput.h header file, the header file generates structure definitions compatible with DirectInput 3.0.

If you do not define DIRECTINPUT_VERSION before including the Dinput.h header file, the header file generates structure definitions compatible with the current version of DirectInput. However, the DirectX 3–compatible structures are available under the same names with "_DX3" appended. For example, the DirectX 3–compatible DIDEVCAPS structure is called DIDEVCAPS_DX3.

You must also use the appropriate versions of the DirectInput and DirectInputDevice interfaces. For versions of DirectX prior to DirectX 7.0, you must use IDirectInput and either IDirectInputDevice or IDirectInputDevice2 (the latter is available for DirectX 5.0 or later.)