LineEdit widget text to QByteArray (\n to 0x0A)

[Andiz]

Hello,

how to conver QString from LineEdit->text() to QByteArray? \n must be converted to byte 0x0A.

Thank You.

[A Former User]

Hi! Depends on the encoding you need in the resulting byte array. E.g., to get a UTF-8 encoded string, you'd use QByteArray QString::toUtf8() const.

[Andiz]

I use
QByteArray data_to_send;
data_to_send = ui->lineEdit_send->text().toUtf8();

and I get two bytes 0x5C 0x6E in byte array when I write in line edit \n
but I need 0x0A

[A Former User]

You could e.g. replace the 2-character-sequence of "\n" in the string before you convert it to a byte array:

data_to_send = QString( ui->lineEdit_send->text() ).replace("\\n", "\n").toUtf8();

[Andiz]

It works, and what about other syntax like \r CR and etc? its possible to convert all of them to hex correctly?

[A Former User]

Sure, just repeat the code from my last post for all sequences you want to replace. A list of the escape sequences used in C++ can be found here. As a side-note, you could also use QRegularExpression instead of QString::replace(). Or you could replace the characters in the byte array, using QByteArray::replace().

[Andiz]

I tryed to use: data_to_send = ui->lineEdit_send->text().replace( "\\" , "\" ).toUtf8();
but the end of this line seems to be commented because there is ""

[A Former User]

.replace( "\" , "" ) is an error in your source code, because \" is the escape sequence for double quote. Have a look at http://en.cppreference.com/w/cpp/language/escape to see how escape sequences in C++ work.

[SGaist]

Hi,

Wouldn't QByteArray::toHex fill the bill ?

[Andiz]

OK. I used this method:
replace("\\'","\'").replace("\\\"", "\"").replace("\\?","\?").replace("\\a","\a").replace("\\b","\b").replace("\\f","\f").replace("\\n","\n").replace("\\r","\r").replace("\\t","\t").replace("\\v","\v")

Thank You