| 本例子举例说明了在LabWindows/CVI中调用SDK函数过程中使用两种方式获得调用句柄。在LabWindows/CVI句柄的数据类型为整型，而在Windows中，句柄的类型通常为HWND类型，这就需要在使用过程中进行强制转换。 如果想在电脑运行时关闭显示器节电，那么可以用如下程序。 程序界面： 程序代码： #include "windows.h"
#include
#include
#include "显示器操作.h" static int panelHandle; int __stdcall WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpszCmdLine, int nCmdShow)
{
if (InitCVIRTE (hInstance, 0, 0) == 0)
return -1; /* out of memory */
if ((panelHandle = LoadPanel (0, "显示器操作.uir", PANEL)) < 0)
return -1;
DisplayPanel (panelHandle);
RunUserInterface ();
DiscardPanel (panelHandle);
return 0;
} int CVICALLBACK QuitCallback (int panel, int control, int event,
void *callbackData, int eventData1, int eventData2)
{
switch (event)
{
case EVENT_COMMIT:
QuitUserInterface (0);
break;
}
return 0;
} //关闭按钮
int CVICALLBACK off (int panel, int control, int event,
void *callbackData, int eventData1, int eventData2)
{
int handle;
switch (event)
{
case EVENT_COMMIT:
//获得面板句柄
GetPanelAttribute (panelHandle, ATTR_SYSTEM_WINDOW_HANDLE, &handle);
//关闭显示器
SendMessage((HWND)handle, WM_SYSCOMMAND, SC_MONITORPOWER, 2);
break;
}
return 0;
} //开启按钮
int CVICALLBACK on (int panel, int control, int event,
void *callbackData, int eventData1, int eventData2)
{
int handle;
switch (event)
{
case EVENT_COMMIT:
//获得CVI窗口句柄
handle = GetCVIWindowHandle();
//打开显示器
SendMessage((HWND)handle, WM_SYSCOMMAND, SC_MONITORPOWER, -1);
break;
}
return 0;
}
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