QT4 Chinese garbled characters

QT4 Chinese garbled characters-general Linux technology-Linux programming and kernel information. The following is a detailed description. For beginners of Linux, go to advanced QT programming. However, the first Demo program encountered a Chinese Garbled text, a great sweat!

Environment:
1. RedHat AS5
2. QT4.4.0
3. LANG = "zh_CN.GB18030"
Program:
...
QTextCodec: setCodecForTr (QTextCodec: codecForName ("gb18030 "));
...
Label. setText (QObject: tr ("the same world, the same dream! "));
...
Result:
The title is displayed normally. Chinese characters of labels and buttons are garbled.

Search online for 3 ~ 4 days, summarized as follows:
1. Use setdefacodecodec to set;
QApp-> setdefacodecodec (QTextCodec: codecForName ("GBK "));
QLabel * label = new QLabel (tr ("Chinese label "));
Unfortunately, setdefacodecodec is a function of QT3, which is no longer supported by QT4.

2. Set the encoding of the QObject member function tr;
QTextCodec: setCodecForTr (QTextCodec: codecForName ("GBK "));

3. Use the fromLocal8Bit () function of QString;
QString str;
Str = str. fromLocal8Bit ("HAHAHA ");
Hello. setWindowTitle (str );

4. Use the toUnicode method of QTextCodec to display Chinese characters.
QLabel hello (QObject: tr ("hello"). toLocal8Bit ());
QTextCodec * codec = QTextCodec: codecForLocale ();
QString a = codec-> toUnicode ("Anshi manual ");

The above issues are not solved.
I still did not search for this question, and finally found the real answer in a blog: font.

"A strange phenomenon found in QT4 is that the Title" I Am a dialog box "in the dialog box can be correctly displayed, and the button is a small square. It seems that some system settings are incorrect, not character encoding. If it is a character encoding problem, it should be garbled rather than a small square. I suddenly thought that the font was mentioned on the Internet. I think it can be explained that the title bar and button text are not the same font, but the button font is not, so it is a small square, rather than Garbled text.
I searched the default font used for QT4 on the Internet. I did not find the default font. I read the source code of QT4 and found too many codes.
However, the setFont function caught my attention. I have seen this method on the Internet ."

Refer to the above content to modify the code:
...
QTextCodec: setCodecForTr (QTextCodec: codecForName ("gb18030 "));
QFont font ("Times", 12, QFont: Normal, FALSE );
App. setFont (font );
...
Label. setText (QObject: tr ("the same world, the same dream! "));
...
Successful! Chinese display is normal!

The solution to this problem is really too important. To tell the truth, it is really a little exhausting. Fortunately, I didn't give up. Yeah!

Note: when using the qt designer, the interface is still garbled. Use qtconfig to set font to Bitstream Charter to solve the garbled problem. At this time, I think the original program is also OK? Unexpectedly, there was no Garbled text ~ Oh MyGod!