int GetSystemMetrics(nIndex)
This function retrieves the system metrics. The system metrics are the widths and heights of various display elements of the Windows display. The GetSystemMetrics function can also return flags that indicate whether the current version is a debugging version, whether a mouse is present, or whether the meaning of the left and right mouse buttons have been exchanged.
| Parameter | Type/Description |
| nIndex | int Specifies the system measurement to be retrieved. All measurements are given in pixels. The system measurement must be one of the values listed in Table R.10, “System Metric Indexes.” |
The return value specifies the requested system metric.
System metrics depend on the system display and may vary from display to display. Table R.10 lists the system-metric values for the nIndex parameter:
Table R.10 System Metric Indexes
| Index | Meaning |
| SM_CXSCREEN | Width of screen. |
| SM_CYSCREEN | Height of screen. |
| SM_CXFRAME | Width of window frame that can be sized. |
| SM_CYFRAME | Height of window frame that can be sized. |
| SM_CXVSCROLL | Width of arrow bitmap on vertical scroll bar. |
| SM_CYVSCROLL | Height of arrow bitmap on vertical scroll bar. |
| SM_CXHSCROLL | Width of arrow bitmap on horizontal scroll bar. |
| SM_CYHSCROLL | Height of arrow bitmap on horizontal scroll bar. |
| SM_CYCAPTION | Height of caption. |
| SM_CXBORDER | Width of window frame that cannot be sized. |
| SM_CYBORDER | Height of window frame that cannot be sized. |
| SM_CXDLGFRAME | Width of frame when window has WS_DLGFRAME style. |
| SM_CYDLGFRAME | Height of frame when window has WS_DLGFRAME style. |
| SM_CXHTHUMB | Width of thumb box on horizontal scroll bar. |
| SM_CYVTHUMB | Height of thumb box on vertical scroll bar. |
| SM_CXICON | Width of icon. |
| SM_CYICON | Height of icon. |
| SM_CXCURSOR | Width of cursor. |
| SM_CYCURSOR | Height of cursor. |
| SM_CYMENU | Height of single-line menu bar. |
| SM_CXFULLSCREEN | Width of window client area for full-screen window. |
| SM_CYFULLSCREEN | Height of window client area for full-screen window (equivalent to the height of the screen minus the height of the window caption). |
| SM_CYKANJIWINDOW | Height of Kanji window. |
Table R.10 System Metric Indexes (continued)
| Index | Meaning |
| SM_CXMINTRACK | Minimum tracking width of window. |
| SM_CYMINTRACK | Minimum tracking height of window. |
| SM_CXMIN | Minimum width of window. |
| SM_CYMIN | Minimum height of window. |
| SM_CXSIZE | Width of bitmaps contained in the title bar. |
| SM_CYSIZE | Height of bitmaps contained in the title bar. |
| SM_MOUSEPRESENT | Nonzero if mouse hardware installed. |
| SM_DEBUG | Nonzero if Windows debugging version. |
| SM_SWAPBUTTON | Nonzero if left and right mouse buttons swapped. |