检查是否已连接上 Internet

一小段检查 Internet 连接的代码:

IF CheckInternetConnection()

MESSAGEBOX( '已经连上 Internet' )

ELSE

MESSAGEBOX( '没有连上 Internet' )

ENDIF

FUNCTION CheckInternetConnection

#define TEST_PROMPT '正在测试 Internet 连接 ...'

#define TEST_URL 'http://www.google.com'

#define INTERNET_OPEN_TYPE_PRECONFIG 0

#define INTERNET_FLAG_RELOAD 0x80000000

#define INTERNET_FLAG_KEEP_CONNECTION 0x00400000

#define INTERNET_FLAG_NO_CACHE_WRITE 0x04000000

DECLARE Long InternetOpen IN wininet ;

String lpszAgent, Long dwAccessType, ;

String lpszProxyName, String lpszProxyBypass, ;

Long dwFlags

DECLARE Long InternetOpenUrl IN wininet.dll ;

Long hInet, String lpszUrl, ;

String lpszHeaders, Long dwHeadersLength, ;

Long dwFlags, Long dwContext

DECLARE Long InternetCloseHandle IN wininet ;

Long hInet

LOCAL hInet, hUrl, iFlags, lOK

m.hInet = InternetOpen( 'ConnectTest', INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0 )

m.lOK = ( 0 != m.hInet )

IF ( m.lOK )

WAIT WINDOW AT SROWS()/2, ( SCOLS() - TXTWIDTH( TEST_PROMPT ) )/2 ;

TEST_PROMPT NOWAIT NOCLEAR

m.iFlags = BITOR( ;

INTERNET_FLAG_KEEP_CONNECTION, ;

INTERNET_FLAG_NO_CACHE_WRITE, ;

INTERNET_FLAG_RELOAD )

m.hUrl = InternetOpenUrl( m.hInet, TEST_URL, NULL, 0, m.iFlags, 0 )

m.lOK = ( 0 != m.hUrl )

IF ( m.lOK )

InternetCloseHandle( m.hUrl )

ENDIF

InternetCloseHandle( m.hInet )

WAIT CLEAR

ENDIF

RETURN m.lOK

ENDFUNC