개발 참고자료

When you have more than one screen attached to a PC, one possible configuration is to see the dual monitors setup as a virtual desktop.

The trick is to get the resolution of the first monitor (the main one) and then position a window on the second screen (right monitor).


First you need to this API to detect if more than one monitor is present.


[local external function definition]
FUNCTION Integer GetSystemMetrics (Integer nIndex) LIBRARY "user32.dll"

In the open event of a window, we position the window at the max value of screen resolution returned by the Powerbuiler environment object.integer SM_CMONITORS = 80
environment myEnv

IF GetSystemMetrics(SM_CMONITORS)> 1 THEN
GetEnvironment(myEnv)
// display on the secondary monitor (right to primary monitor!)
this.x = PixelsToUnits(myEnv.ScreenWidth, XPixelsToUnits!)
this.y = 0
END IF

Now if you want to center the window displayed on the second monitor, you need to get the resolution on that monitor. The Powerbuilder environment object returns only the resolution of the main monitor. To get the resolution of the second monitor, you need to call two Windows APIs.[local external function definition]
FUNCTION Long MonitorFromWindow (Long hwnd, Long dwFlags) LIBRARY "user32"
FUNCTION Long GetMonitorInfo (long hMonitor, ref tagmonitorinfo moninfo) &
LIBRARY "user32" ALIAS FOR "GetMonitorInfoA"

A structure, tagmonitorinfo, is defined to contain the informations returned by the API.


We position the window on the second monitor. We call the MonitorFromWindow API to get an identifer for the monitor as seen by Windows. Then with the identifier, we call another API to the associated screen resolution.


integer SM_CMONITORS = 80
integer MONITOR_DEFAULTTONULL = 0

IF GetSystemMetrics(SM_CMONITORS)> 1 THEN
environment myEnv
long monitor
tagmonitorinfo tmi
int x1
int y1

GetEnvironment(myEnv)
// move to the second monitor (right to primary monitor!)
this.x = PixelsToUnits(myEnv.ScreenWidth, XPixelsToUnits!)
this.y = 0

// get the resolution of the second monitor
monitor = MonitorFromWindow(Handle(w_yop), MONITOR_DEFAULTTONULL)

IF NOT isNull(monitor) THEN
tmi.cbSize = 72 // size in bytes of TAGMONITORINFO
GetMonitorInfo(monitor, tmi);
// the resolution
x1 = tmi.rcMonitor.right - tmi.rcMonitor.left;
y1 = tmi.rcMonitor.bottom - tmi.rcMonitor.top;

// display center on the secondary monitor (right to primary monitor!)
this.X = PixelsToUnits(myEnv.ScreenWidth, XPixelsToUnits!) + &
(( PixelsToUnits(x1, XPixelsToUnits!) - this.Width ) / 2)
this.Y = ( PixelsToUnits( y1, YPixelsToUnits! ) - this.Height ) /2
END IF
END IF

If the second monitor is to the left of the primary monitor then to position a window we need to use a negative value.

integer SM_CMONITORS = 80
integer MONITOR_DEFAULTTONULL = 0

IF GetSystemMetrics(SM_CMONITORS)> 1 THEN
environment myEnv
long monitor
tagmonitorinfo tmi
int x1
int y1

GetEnvironment(myEnv)
// move to the second monitor (left to primary monitor)
this.x = -1 * (this.Width)
this.y = 0

// get the resolution of the second monitor
monitor = MonitorFromWindow(Handle(w_yop), MONITOR_DEFAULTTONULL)

IF NOT isNull(monitor) THEN
tmi.cbSize = 72 // size in bytes of TAGMONITORINFO
GetMonitorInfo(monitor, tmi);
// the resolution
x1 = tmi.rcMonitor.right - tmi.rcMonitor.left;
y1 = tmi.rcMonitor.bottom - tmi.rcMonitor.top;

// display center on the secondary monitor (left to primary monitor!)
this.X = -1 * ( PixelsToUnits(x1, XPixelsToUnits!) - &
(PixelsToUnits(x1, XPixelsToUnits!) - this.Width ) / 2)
this.Y = ( PixelsToUnits( y1, YPixelsToUnits! ) - this.Height ) /2
END IF
END IF