程序代码：

PUBLIC gcOldDir,vcxname
gcOldDir = SET('DEFAULT') + SYS(2003)
SET DEFA TO "&gcOldDir"
******************************************************************************
&&获取程序运行名称
Declare INTEGER GetModuleHandle IN kernel32 INTEGER lpModuleName
vcxid = ALLTRIM(STR(GetModuleHandle(0)))

Declare INTEGER GetModuleFileName IN kernel32;
INTEGER hModule,;
STRING @ lpFilename,;
INTEGER nSize

lpFilename = SPACE(250)
lnLen = GetModuleFileName (0, @lpFilename, Len(lpFilename))
vcxname = JUSTFNAME(ALLTRIM(Left (lpFilename, lnLen)))
******************************************************************************
#DEFINE ERROR_ALREADY_EXISTS 183 
DECLARE INTEGER GetLastError IN WIN32API
DECLARE INTEGER CreateMutex IN WIN32API INTEGER Security,SHORT Owned,STRING@ MutexName
DECLARE SHORT CloseHandle IN WIN32API INTEGER

PUBLIC hMutex, iResult, bCanRun
hMetux=CreateMutex(0,0,vcxname)
iResult=GetLastError()
DO CASE 
   CASE iResult==0
        bCanRun=.T.
   CASE iResult==ERROR_ALREADY_EXISTS
        MessageBox("程序已经运行。"+SPACE(2),64,"提示")
        bCanRun=.F.
   OTHERWISE 
        bCanRun=.F.
        MessageBox("GetLastError() returned "+ ltrim(str(iResult))) 
ENDCASE 

IF bCanRun ==.F.
   =CloseHandle(hMutex)
*   QUIT
ENDIF

[此贴子已经被作者于2016-7-25 14:56编辑过]