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How to Use Pager Controls

This section describes how to implement the pager control in your application.

What you need to know

Technologies

Prerequisites

  • C/C++
  • Windows User Interface Programming

Instructions

Initialize a Pager Control

To use the pager control, you must call the InitCommonControlsEx function with the ICC_PAGESCROLLER_CLASS flag set in the dwICC member of the INITCOMMONCONTROLSEX structure.

Create a Pager Control

Use the CreateWindow or the CreateWindowEx API to create a pager control. The class name for the control is WC_PAGESCROLLER, which is defined in Commctrl.h. The PGS_HORZ style is used to create a horizontal pager, and the PGS_VERT style is used to create a vertical pager. Because this is a child control, the WS_CHILD style should also be used.

After the pager control is created, you will most likely want to assign a contained window to it. If the contained window is a child window, you should make the child window a child of the pager control so that the size and position will be calculated correctly. You then assign the window to the pager control with the PGM_SETCHILD message. Be aware that this message does not actually change the parent window of the contained window; it simply assigns the contained window. If the contained window is one of the common controls, it must have the CCS_NORESIZE style to prevent the control from attempting to resize itself to the pager control's size.

Process Pager Control Notifications

At a minimum, it is necessary to process the PGN_CALCSIZE notification. If you do not process this notification and enter a value for the width or height, the scroll arrows in the pager control will not be displayed. This is because the pager control uses the width or height supplied in the PGN_CALCSIZE notification to determine the "ideal" size of the contained window.

The following example demonstrates how to process the PGN_CALCSIZE notification case. In this example, the contained window is a toolbar control that contains an unknown number of buttons at an unknown size. The example shows how to use the TB_GETMAXSIZE message to determine the size of all of the items in the toolbar. The example then places the width of all of the items into the iWidth member of the NMPGCALCSIZE structure that is passed to the notification.

case PGN_SCROLL:{

    LPNMPGSCROLL pScroll = (LPNMPGSCROLL)lParam;
 
    switch(pScroll->iDir){
     
        case PGF_SCROLLLEFT:
        case PGF_SCROLLRIGHT:
        case PGF_SCROLLUP:
        case PGF_SCROLLDOWN:
     
            pScroll->iScroll = 20;
        
            break;
        }
    }
  
return 0;

Using Pager Controls

Windows common controls demo (CppWindowsCommonControls)