Qt5：QTextEdit到（LPVOID lpBuffer，DWORD dwBytesToWrite）

Question

I have a GUI with textDataToSend QTextEdit field and I want to use the data entered in a fWrite function which accepts (LPVOID lpBuffer, DWORD dwBytesToWrite) arguments.

For now I use:

dataToSend[0] = ui->textDataToSend->toPlainText().toUInt(&bStatus,16);
sendData(dataToSend,1);

where sendData is like:

DWORD sendData(char* txBuffer, unsigned long txBufferSize) {
    int status;
    status = fWrite(handle, txBuffer, txBufferSize);
    return status;
}

With that I am able to send one byte.

The data I would like to use are hex strings with variable length (like "aa0011", "1122334455", ...). I'm totally unexperienced, could you please suggest some good, proper, more clever way to do that?

Answer 1

First get the QString out of the Text edit

QString textEditString = ui->textDataToSend->toPlainText();

When you have QString in your hand, you can get both "buffer" and "size of the buffer" as shown below.

//First get the byte array from the string
QByteArray bArray = textEditString.toLatin1();

//Get the size of the string in bytes
int length = bArray.size(); 

//Get the string buffer
char *tBuffer = bArray.data();

Now pass these values to your send data

sendData(tBuffer, length);

Any how LPVOID is nothing but a Void pointer. fWrite should be able to take tBuffer with out any problem.