CODEWITHSUNDEEP
c++qtunicodeqt5std
Bleach
Bleach

Reputation: 156

QString to std::string Unicode trouble

In this simple code I have trouble with Unicode:

QString qs = QFileDialog::getOpenFileName(0,"","","");
std::string str = qs.toUtf8().constData();
Mat m = imread(str);

When qs is Latin char set it works fine, but when path contains Cyrillic chars I obtain a bad conversion. As sample: qs "E:/Кирилиця_49.png": str "E:/Кирилиця_49.png"

I know that happens when str is not on UTF-8 characters set, but in project properties the "Character Set" property is "Use Unicode Character Set". Compiler MSVC 2010, Qt 5.3.2. What could be the problem?

Upvotes: 1

Views: 2306

Answers (1)

Mr.C64
Mr.C64

Reputation: 42924

I believe QString::toUtf8() is doing its job right (modulo some bug in Qt's implementation...).

The problem could be that you are using a debugger visualizer for the content of std::string that is showing the string interpreting it using some "code page" instead of Unicode UTF-8.

Basically, the string content (as raw bytes) is correct (it's just the UTF-8 byte sequence corresponding to the original Unicode UTF-16 string): you are just using some "wrong-colored glasses" to look at it :)

The important point is: in what format does the imread() function expect its string parameter to be? If imread() expects an UTF-8 string, then you are right in passing a std::string with UTF-8 encoded string to it as argument.

Upvotes: 1

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