Passing numeric data as character strings to instruments and then converting the strings to numerics.Learn the execution order of a property node.Ī string is a sequence of displayable or non-displayable ASCII characters.Strings provide a platform-independent format for information and data.Some of the more common applications of strings include the following: Learn to access files through a user interface. Objective Learn the various string display types. In addition, property nodes will be introduced as a means of changing front panel objects programmatically. You will also write simple VIs to write and read to and from files in LabVIEW as a form of data management. If you let it be treated as a string, functions are liable to stop processing it at any \0 but then if it is a string that's fair enough.īTW, great username for this forum, must be really easy to remember.IntroductionIn this homework, you will learn about strings. In a nutshell, always pass a length/count around with a byte array ( QByteArray has that), any operations should respect that byte count and not care about any embedded \0. You can probably forget it's there and never worry about it.Ī CString is what? A Microsoft MFC class for handling strings? No idea about its representation or compatibility with whatever.Īnyway, I'm sorry but I can't figure just what you asking/saying, where exactly what problem is. That extra byte is not including in the QByteArray's count/length, and is only there to make it a bit interoperable with QStrings. Qt QByteArrays have the unusual property of always having an extra \0 at the end of the data, no matter what the data contains. When you talk about "Byte Array" at various points in your question, how do we know which of LV Byte Array or QByteArray you mean? I don't know what the rules for a LabView Byte array might be. strcpy() might handle a \0 it encounters, but that is nothing to do with it being char *. Something being char * has no relevance/effect on whether it has or how it handles a \0 it might contain. Thanks for your said in QByteArray to LabVIEW Byte Array conversion: I can't specify a minimal length because my serialization return me Byte Array with random length (it can be 8 bytes, 7 bytes, or 70 !) In LabVIEW, I put a CLFN (Call Library Function Node) and just I send and get CString pointer. QByteArray serializedArray = QByteArray(serializedMessage.c_str(), serializedMessage.length()) Std::string serializedMessage = requete.SerializeAsString() Qt DLL encoder : (I give string or numeric, I wan't get a Byte Array to send on my websocket) const char* m圜lass::LVSetPower(int8_t l) decoding and assign string to response QByteArray receivedMessage(receivedMessageString, length) Qt DLL decoder : (I give a Byte Array, I get a string) const char* m圜lass::decodeMsg(char* receivedMessageString, int32_t length) How could I do to implement these conversions properly ? This works well for strings but for Byte Array, the final 0 (which is a value for me and I want to get it) is not returned. This DLL returns a string OR an Byte Array.Ĭurrently, I use const char*. These Byte Array are sent to a DLL written with Qt to be deserialized (LV Byte Array -> QByteArray conversion). I have a main application in LabVIEW that retrieves Byte Array from a websocket.
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