The DDX_Slider function manages the transfer of int data between a slider control in a dialog box or form view and an int data member of the dialog box or form view object.
void AFXAPI DDX_Slider( CDataExchange* pDX, int nIDC, int& value );
A pointer to a CDataExchange object. The framework supplies this object to establish the context of the data exchange, including its direction.
The resource ID of the slider control.
A reference to the value to be exchanged. This parameter holds or sets the slider control's current position.
When DDX_Slider is called, value is set to the current position of the control's thumb, or the value receives the position, depending on the direction of the exchange.