Name

Type

Optional

Meaning

hwnd

Number

No

Handle of the dialog containing the control

ctrlID

Number

No

Control identifier assigned to the control during CONTROL ADD ...

hCtrl

Variable

No

The returned value is the window handle for the control.

When the control was created Windows uniquely identifying it from all other controls.

Window handle is required by some functions working directly with windows API.

Window handle is different from Control ID.

Control ID is chooses by programmer. Window handle is automatically assigned by Windows when control is created.