Use API Functions that Require a STRUCT

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File: ...\Samples\Solution\Winapi\Systime.scx

This example illustrates calling the Windows API function GetSystemTime. GetSystemTime fills in a structure of WORD (16-bit unsigned integer) values with system time information.

C Function Declaration and Struct Definition

VOID GetSystemTime(
    LPSYSTEMTIME lpSystemTime    // address of system time structure  
   );

This is the struct definition:

typedef struct _SYSTEMTIME {
    WORD wYear; 
    WORD wMonth; 
    WORD wDayOfWeek; 
    WORD wDay; 
    WORD wHour; 
    WORD wMinute; 
    WORD wSecond; 
    WORD wMilliseconds; 
} SYSTEMTIME;

Calling the Function in Visual FoxPro

The Visual FoxPro code passes GetSystemTime, a reference to a character variable, which is filled in with the WORD values.

* Visual FoxPro Code: cmdSystemTime.Click
DECLARE INTEGER GetSystemTime IN win32api STRING @
cBuff=SPACE(40)

GetSystemTime(@cBuff)

To retrieve the information from the character variable, cBuff, the following code converts 8-bit ASCII characters for year and month in the variable into 16-bit equivalents.

THIS.Parent.lblYear.Caption = ALLTRIM(STR(ASC(SUBSTR(cBuff,2)) * 256 + ASC(SUBSTR(cBuff,1))))

THIS.Parent.lblMonth.Caption = MONTH_LOC + ALLTRIM(STR(ASC(SUBSTR(cBuff,4)) * 256 + ASC(SUBSTR(cBuff,3))))

See Also

Use API Functions That Require Pointers to Arrays | Solutions Sample Overview | Visual FoxPro Foundation Classes A-Z