LXE Akerstroms Tx700, Руководство по настройке, Страница: 138 / 146

Custom OS Installations Trux Configuration Guide
138 E-EQ-TRUXCONFIG-D-ARC
The method OnCopyData below is a handler for the WM_COPYDATA message. It receives a
COPYDATASTRUCT structure pointer. The member lpData of that struct contains the data string
from WLinq. lpData is a string pointer. The receiving program must call the function ReplyMessage
as soon as the data string has been saved in a variable because WLinq hangs until either
ReplyMessage is called or the processing of the WM_COPYDATA message is finished. If
ReplyMessage is not called, a data string sent from the receiving program to WLinq will be delayed.
Please note that the COPYDATASTRUCT structure should be considered invalid after the call to
ReplyMessage.
In the sample above, the message WM_COPYDATA is received from WLinq. The data string from
WLinq is saved in the strCode string object. The string "B1\r" is then sent to WLinq (that later
sends it to the serial port). The string "B1\r" is a Beep command for a certain barcode reader.
ReplyMessage is called so WLinq will be released and enable WLinq to process the string "B1\r".
The data string is then added to a list box. This represents a lengthy operation like a database
query, file access or similar.