Qt 编码设置

Qt 编码设置

1.
Qt Creator -> 工具 -> 选项 -> 环境 -> 语言
Qt Creator本身界面的语言选择
与cpp文件编码无关,与可执行文件显示编码无关
重新打Qt Creator 此设置才能生效
这个唯一选择<Chinese>

2.
Qt Creator -> 工具 -> 选项 -> 环境 -> 默认文件编码
决定cpp文件编码
不同平台下,此设置要相同,如果不同,cpp文件会有好多乱码,且不能被编辑,但不影响编译;
重新打Qt Creator 此设置才能生效
这个推荐选<UFT-8>,因为linux下是这个;
如果不同:
选择<根据编码重新载入>这步选择文件的原始编码
再<根据编码保存>这步选择目标编码

3.
QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));
只与这个相关QString str = tr("中文");
注意,相关的是转换过程,QString本身是unicode,不会影响到QString
这个必须和<2. Qt Creator -> 工具 -> 选项 -> 环境 -> 默认文件编码>相同
推荐选<UFT-8>

4.
QTextCodec::setCodecForCStrings(QTextCodec::codecForName("UTF-8"));
只与这个相关QString str = QString("中文");
注意,相关的是转换过程,QString本身是unicode,不会影响到QString
这个必须和<2. Qt Creator -> 工具 -> 选项 -> 环境 -> 默认文件编码>相同
推荐选<UFT-8>

5.QTextCodec::setCodecForLocale(QTextCodec::codecForName("UTF-8"));
只与这个相关QString str = QString::fromLocal8Bit("中文");
以上2个最好都不用,用以下的

// 常规做法举例之GB2312  ,注意"UTF-16"的输入是要带BOM的 
QTextCodec *pCodec = QTextCodec::codecForName("GB2312");// "UTF-8", "UTF-16"
GB2312转QString: pCodec->toUnicode();
QString转GB2312: pCodec->fromUnicode();

// 另外QString类分别针对"UTF-8", "UTF-16"做了专门的函数, 当然结果同常规做法是一样的,例子如下:

// Unicode(utf8)(3个字节/汉字, 1个字节/字母)
UTF-8转QString: QString::fromUtf8();
QString转UTF-8: QString.toUtf8();

// Unicode(utf16) Unicode(ucs2) Unicode(iso-10646-ucs-2)  2个字节/字符,也是windows记事本里那个Unicode
// qt中表示UTF-16要用ushot,不要用wchar_t(wchar_t大小根据编译器而定)
UTF-16转QString: QString::fromUtf16(); 这个带2个字节的BOM头; [0xFF 0xFE](61,00) [0xFE 0xFF](00,61)
QString转UTF-16:  QString.utf16(); 返回以0结尾的ushot数组

6.
Qt Creator -> ui面板上控件直接设成中文内容
无相关,设成什么就是什么,因为QString本身是unicode
保存到<ui_***.h>文件文件时是这样写的
label->setText(QApplication::translate("Dialog", "\346\210\221\344\273\254", 0, QApplication::UnicodeUTF8));
或label->setText(QString::fromUtf8("\346\210\221\344\273\254"));

7.文本文件的编码

windows平台文本文件有BOM
        ANSI:没有文件头,2字节/汉字,1字节/英文
        UTF-8:文件头[0xEF,0xBB,0xBF],3字节/汉字,1字节/英文
        Unicode:文件头[0xFF,0xFE],2字节/汉字,2字节/英文
        Unicode big endian :文件头[0xFE,0xFF],同Unicode,字节序相反

Linux平台UTF-8和GB2312文件都没有BOM
Linux平台UTF-16同windows一样,有BOM且相同

8.
("GBK", "CP936", "MS936", "windows-936", "roman8", "hp-roman8", "csHPRoman8", "TIS-620", "ISO 8859-11",

"WINSAMI2", "WS2", "Apple Roman", "macintosh", "MacRoman", "windows-1258", "CP1258", "windows-1257",

"CP1257", "windows-1256", "CP1256", "windows-1255", "CP1255", "windows-1254", "CP1254", "windows-1253",

"CP1253", "windows-1252", "CP1252", "windows-1251", "CP1251", "windows-1250", "CP1250", "IBM866", "CP866",

"csIBM866", "IBM874", "CP874", "IBM850", "CP850", "csPC850Multilingual", "ISO-8859-16", "iso-ir-226", "latin10",

"ISO-8859-14", "iso-ir-199", "latin8", "iso-celtic", "ISO-8859-13", "ISO-8859-10", "iso-ir-157", "latin6", "ISO-8859-

10:1992", "csISOLatin6", "ISO-8859-9", "iso-ir-148", "latin5", "csISOLatin5", "ISO-8859-8", "ISO 8859-8-I", "iso-ir-

138", "hebrew", "csISOLatinHebrew", "ISO-8859-7", "ECMA-118", "greek", "iso-ir-126", "csISOLatinGreek", "ISO-

8859-6", "ISO-8859-6-I", "ECMA-114", "ASMO-708", "arabic", "iso-ir-127", "csISOLatinArabic", "ISO-8859-5",

"cyrillic", "iso-ir-144", "csISOLatinCyrillic", "ISO-8859-4", "latin4", "iso-ir-110", "csISOLatin4", "ISO-8859-3", "latin3",

"iso-ir-109", "csISOLatin3", "ISO-8859-2", "latin2", "iso-ir-101", "csISOLatin2", "KOI8-U", "KOI8-RU", "KOI8-R",

"csKOI8R", "UTF-8", "ISO-8859-1", "latin1", "CP819", "IBM819", "iso-ir-100", "csISOLatin1", "ISO-8859-15", "latin9",

"UTF-32LE", "UTF-32BE", "UTF-32", "UTF-16LE", "UTF-16BE", "UTF-16", "System", "Iscii-Mlm", "Iscii-Knd", "Iscii-

Tlg", "Iscii-Tml", "Iscii-Ori", "Iscii-Gjr", "Iscii-Pnj", "Iscii-Bng", "Iscii-Dev", "TSCII", "GB18030", "GB2312", "EUC-JP",

"ISO-2022-JP", "Shift_JIS", "JIS7", "SJIS", "MS_Kanji", "EUC-KR", "cp949", "Big5", "Big5-HKSCS", "Big5-ETen",

"CP950")