VS2012中QT资源文件qrc加载失败(Q_INIT_RESOURCE报错)
在QT中如果需要使用资源时，会用到一个qrc文件.qrc文件本质上是一个XML文件，里面描述了相应资源的位置。一般将需要引用的资源放到与main.cpp同级的目录。我用VS2012开发QT，如果按正常的情况来建立QT，会带有一个qrc文件和对就的qrc*.cpp的文件，如下图（qrcexample.qrc和qrc_qrcexample.cpp）。
其中qrc_qrcexample.cpp是自动生成的，是在qrc名字的前面加了一个qrc_的前缀。如果这样正常添加资源文件是没有问题的，但是我却误删了qrc_qrcexample.cpp文件。等到想用qrc来加载图片时，按着正常的操作，在qrcexample.qrc中加了相应的图片，可是编译之后，怎么引用路径都无法得到图片。这到底是怎么了？找了很多资料，说是可以用Q_INT_RESOURCE在main函数中强制加载qrc文件，可是却报错了。（附：Q_INT_RESOURCE的调用方式是，Q_INT_RESOURCE(qrc文件名)，注意一定要是qrc文件名。）
一般来说，无法解析外部符号，是因为函数有定义却没有去实现。那这里的qInitResources_qrcexample(void)根本就没有定义过，又怎么可能去实现呢？那只有一种解释，该函数是由系统自动生成并实现了。现在系统生成了该函数的定义，却没有相应的实现。那怎么办？
于是网上查找资料，后面找到了一篇文章，说是系统会生成一个与qrc资源文件相对应的CPP（也就是前面误删的qrc_qrcexample.cpp）。既然误删了，那是不是可以再建一个相同的？结果证明，这种想法太天真了。因为只是建一个这样的文件，里面什么内容都没有，那不是形同虚设吗？
想着，这个文件既然是系统生成的，那必然会在系统中有所配置，可是在找遍了配置项后，都没有找到一个对应的。后面就想着，VS的工程文件中有对引用和编译信息的配置，会不是存在那里呢？如果存在了那里，那我又要如何才能分辨出哪个是呢？最后的办法就是找一个正常的来对比。立即新建一个项目test，自动生成了test.qrc和qrc_test.cpp，用UE打开test.vcxproj，是一个XML格式的文件，搜索qrc_test.cpp，果然有相应的配置信息。
然后重新加载项目，这时系统自动生成了qrc_qrcexample.cpp，其内容如下。
/****************************************************************************
** Resource object code
**
** Created by: The Resource Compiler for Qt version 5.1.1
**
** WARNING! All changes made in this file will be lost!
*****************************************************************************/
#include
QT_BEGIN_NAMESPACE
QT_END_NAMESPACE
int QT_MANGLE_NAMESPACE(qInitResources_qrcexample)()
{
return 1;
}
Q_CONSTRUCTOR_FUNCTION(QT_MANGLE_NAMESPACE(qInitResources_qrcexample))
int QT_MANGLE_NAMESPACE(qCleanupResources_qrcexample)()
{
return 1;
}
Q_DESTRUCTOR_FUNCTION(QT_MANGLE_NAMESPACE(qCleanupResources_qrcexample))
这时再编译，已经OK了。再回过头来看一下，会看到前面报错的qInitResources_qrcexample，这个文件中已经有相应的实现了。不过，仔细的朋友会发现，这个文件已经不是在GeneratedFiles的文件夹下，而是在SourceFiles文件夹了。那会不会有影响呢？我们可以添加一些资源进去，编译后资源会被写到qrc_qrcexapmle.cpp中，那一串串的十六进制就是图片的数据。测试结果证明是OK的。
/****************************************************************************
** Resource object code
**
** Created by: The Resource Compiler for Qt version 5.1.1
**
** WARNING! All changes made in this file will be lost!
*****************************************************************************/
#include
static const unsigned char qt_resource_data[] = {
// G:/Code/QT/QrcExample/QrcExample/images/about.png
0x0,0x0,0x4,0xad,
0x89,
0x50,0x4e,0x47,0xd,0xa,0x1a,0xa,0x0,0x0,0x0,0xd,0x49,0x48,0x44,0x52,0x0,
0x0,0x0,0x20,0x0,0x0,0x0,0x20,0x8,0x6,0x0,0x0,0x0,0x73,0x7a,0x7a,0xf4,
0x0,0x0,0x4,0x74,0x49,0x44,0x41,0x54,0x58,0x85,0xd5,0x96,0xcd,0x6f,0x1b,0x45,
0x18,0xc6,0x9f,0x9d,0x5d,0xaf,0xbd,0xb6,0x93,0x6e,0x5d,0xb7,0x84,0x34,0x6a,0xd2,
0xb4,0x4d,0x8a,0xd4,0x95,0x82,0x44,0x11,0x42,0x95,0xaa,0x52,0x50,0x85,0x8a,0x44,
0x55,0xe,0x80,0xc4,0xa1,0x2a,0xfc,0x1,0xec,0x1,0xe,0x70,0xe8,0x21,0x12,0xb7,
0xca,0x27,0x24,0x40,0xa2,0x42,0xa8,0x2,0x71,0xea,0x1,0x89,0xb,0x8,0x4a,0x85,
0x42,0x94,0xa6,0xa1,0xad,0xab,0x7c,0xb8,0x51,0xbe,0x1c,0xa7,0x76,0xba,0x4d,0xd7,
0xde,0x5d,0x7b,0xbf,0x66,0x87,0x83,0x71,0x71,0xea,0x38,0x71,0x20,0x29,0xe2,0xb9,
0xed,0xbb,0x33,0xf3,0xfc,0xe6,0xeb,0x7d,0x7,0xf8,0x8f,0xc5,0x6d,0xaa,0x75,0x2a,
0x2d,0x2,0x38,0x2,0xe0,0x60,0x9b,0xc8,0x77,0x46,0x42,0x24,0xe,0x0,0xb6,0x17,
0x98,0x86,0x4b,0xf3,0x0,0x32,0x0,0xee,0x40,0x55,0xdc,0xad,0x3,0x48,0xa5,0x13,
0x31,0x91,0xbc,0x75,0x70,0x97,0xf4,0x46,0x42,0x12,0x5e,0x4c,0x46,0x43,0x91,0x84,
0x24,0x40,0xe,0xf3,0x88,0xf0,0xd5,0xee,0x36,0x65,0xd0,0x1d,0x8a,0x15,0xdb,0x87,
0x66,0x79,0xf6,0xc3,0x8a,0x3f,0x34,0xfd,0xc0,0xbe,0x62,0xba,0xf4,0x1b,0xa8,0xca,
0xca,0x3f,0x3,0x48,0xa5,0x3b,0xba,0xda,0xc5,0x8f,0xfb,0x77,0x47,0xcf,0x1f,0x4e,
0x4a,0xd1,0x23,0x3b,0x45,0xb4,0x8b,0x4,0x22,0x1,0x78,0x8e,0x43,0x85,0x32,0x94,
0xc,0x1b,0x1c,0xc7,0xa1,0x2d,0x1e,0x86,0xc4,0x73,0xa0,0x8c,0xc1,0xb,0x80,0x92,
0x17,0x20,0xbd,0xe2,0x62,0x4a,0xab,0xd8,0x13,0xf7,0xcb,0x97,0x72,0x25,0x77,0x10,
0xaa,0x92,0x6f,0xd,0x20,0x95,0x46,0x9b,0xc8,0xbf,0xf7,0x5c,0x57,0xfc,0xe2,0xb3,
0x1d,0xb1,0xf6,0xa7,0x24,0x1e,0x61,0x9e,0xc3,0x82,0xe9,0xc3,0x9,0xaa,0x4d,0xdc,
0x8a,0x8b,0x58,0xae,0x80,0x13,0xbd,0x6d,0xa0,0x1,0xc3,0x4f,0x33,0x16,0x68,0x4f,
0x7,0x4,0x51,0x0,0x0,0x84,0x9,0xb0,0x2f,0x2e,0xc0,0xd,0x18,0xa,0x65,0x8a,
0xb1,0xbc,0x55,0x1a,0xcd,0x99,0x1f,0x18,0xe,0xfd,0x2,0xaa,0xb2,0xe,0x40,0x2a,
0x2d,0x76,0xb5,0x8b,0x9f,0x1f,0xdf,0x2f,0x9f,0x93,0x25,0x1,0x22,0x1,0xdc,0xa0,
0x91,0x9a,0x4e,0xe7,0xf0,0xc9,0x6b,0xfb,0x20,0xf0,0x4,0x0,0x60,0xbb,0x14,0x1f,
0xfe,0xb0,0x88,0xd8,0xa1,0xce,0x86,0xb6,0x61,0x2,0x38,0x1,0x50,0xb4,0x7d,0xfc,
0x3a,0xab,0x5f,0xce,0x16,0xdd,0x77,0xeb,0xcf,0x8,0xa9,0x33,0x27,0xdd,0x72,0xf8,
0xdb,0x53,0x7d,0x89,0x73,0xb2,0x54,0x9d,0xc9,0x5a,0xe6,0x0,0xd0,0xdd,0xc6,0x3f,
0x32,0x7,0x80,0x88,0xc8,0xa3,0x2b,0x4a,0xd6,0x6c,0x5b,0x5b,0xb5,0x1d,0x11,0x1,
0xa7,0xe,0x25,0xde,0xe9,0x96,0xc3,0xdf,0x21,0x95,0x16,0x1a,0x0,0x92,0xd1,0xd0,
0xe0,0x89,0x5e,0xf9,0x6c,0x44,0x58,0x7b,0xa0,0x7a,0xdd,0x2d,0x5,0xb0,0x6c,0xff,
0xd1,0xb7,0x6e,0xb9,0x98,0xaf,0xb0,0xd,0xfb,0x85,0x5,0x82,0x97,0xe,0xc8,0x67,
0x76,0xc7,0x42,0x83,0xb5,0x58,0x75,0xb,0x52,0xe9,0x81,0xd3,0xfd,0x89,0xeb,0x3d,
0x3b,0x23,0x42,0xd3,0xde,0x75,0xa2,0x1e,0x85,0x3f,0x97,0xc7,0xf3,0x49,0x1,0x94,
0x1,0x23,0xf,0x28,0x22,0xbd,0x1d,0x20,0xfc,0xc6,0xf0,0x0,0xb0,0xa0,0xdb,0xc1,
0xf7,0x93,0x2b,0x47,0xa1,0x2a,0x63,0x2,0x0,0x1c,0xdc,0x15,0xb9,0xd0,0xaa,0x39,
0x0,0xf0,0x21,0x1e,0xfc,0xa1,0xbd,0xb8,0xc9,0xaa,0xb3,0x8e,0x26,0x36,0x97,0x4e,
0xf6,0xc9,0x11,0xd2,0x97,0x94,0x2e,0x64,0x80,0xd7,0x39,0xa4,0xd2,0x89,0x97,0xf,
0xc8,0x85,0xfe,0xdd,0xd1,0x96,0x1,0x9c,0xb2,0x3,0xdf,0xf1,0x57,0xc5,0x42,0x91,
0x10,0x44,0x49,0x6c,0x19,0x22,0xa3,0x95,0xfd,0x1f,0xa7,0xf5,0xbd,0x2,0x80,0x63,
0x7b,0xdb,0xc3,0x2d,0x9b,0x3,0x80,0xbf,0xa8,0xe1,0xfc,0x80,0xbc,0x2a,0xf6,0xe9,
0x1f,0x1a,0x92,0xfd,0x8d,0xb7,0xa0,0x99,0xfe,0xf2,0x3c,0x26,0x84,0x79,0xae,0x37,
0x26,0xb6,0xb6,0x77,0x35,0x85,0x43,0x3c,0x6,0xf6,0xaf,0x6,0xe0,0x6f,0x95,0x36,
0x35,0x46,0x4c,0xe4,0x21,0x85,0x48,0xf,0x11,0x78,0x4e,0xe0,0xb8,0xcd,0xed,0xe1,
0x56,0x49,0x20,0x9c,0x40,0x2c,0x37,0x58,0x76,0x69,0x93,0xb,0xbf,0x8d,0xf2,0x29,
0x83,0xe9,0x50,0x8d,0x0,0x18,0x2d,0x98,0xde,0x13,0x7,0x28,0x58,0x2e,0x18,0x30,
0x4a,0x0,0x8c,0x67,0x8b,0xce,0xf8,0x93,0x6,0x58,0x2c,0x3a,0x19,0x0,0xb7,0x9,
0x54,0x5,0x13,0xcb,0xd6,0xc5,0xd2,0x63,0xd7,0x6a,0x3b,0x65,0xba,0x14,0xe3,0xcb,
0xe5,0x8b,0x50,0x95,0x6a,0x2a,0xb6,0x7d,0xf6,0xd5,0x48,0xd6,0x18,0x62,0x6c,0xe3,
0x74,0xfa,0x6f,0xc5,0x18,0xc3,0x48,0xd6,0x18,0x29,0x7b,0xc1,0x25,0xa0,0x56,0xb,
0x54,0x25,0x98,0xd2,0x2a,0x6f,0x8f,0x2d,0x99,0x6b,0xd6,0xec,0xad,0xd4,0xcd,0x7b,
0x56,0x7e,0xe2,0x7e,0xf9,0x4d,0xa8,0x8a,0xff,0x37,0x40,0x15,0x62,0x61,0x38,0x6b,
0x9c,0xbc,0x91,0x33,0x96,0xb6,0x63,0x25,0x18,0x63,0x18,0x5b,0x32,0xf2,0x43,0xb,
0xa5,0x53,0x50,0x95,0xb9,0x5a,0x7c,0x75,0x6,0x52,0x95,0xf1,0xe1,0xac,0x71,0xf4,
0xe7,0x19,0xfd,0x9a,0xe5,0xd2,0x2d,0x33,0xb7,0x5c,0x8a,0x5f,0x66,0xf4,0xa1,0xdf,
0x17,0x8c,0xa3,0x50,0x95,0xdb,0xf5,0xff,0x1a,0x53,0xb0,0xaa,0x2c,0x4d,0xa6,0xd2,
0x27,0xb2,0x45,0xe7,0xa3,0x33,0xcf,0x24,0x7,0x6b,0x6f,0x83,0x7a,0x39,0x1e,0xc5,
0xcd,0x59,0x7d,0x55,0x8c,0x6,0x8d,0xab,0xe6,0xf8,0x1,0x26,0xef,0x97,0xb5,0xdb,
0x79,0xeb,0x42,0xc9,0xa1,0x9f,0x41,0x55,0x1a,0x12,0xce,0x7a,0x6f,0xc2,0x33,0xea,
0xb,0x4f,0x5f,0x39,0xbc,0x23,0x84,0x82,0x1d,0x60,0xd9,0x9,0x50,0xb3,0x58,0xaf,
0x18,0x79,0x34,0xc0,0x52,0xc9,0xc5,0x3d,0xc3,0x1d,0x9b,0xd2,0xca,0x5f,0x9a,0x6e,
0xf0,0x35,0x54,0xc5,0x6c,0x66,0xd3,0xb4,0x8,0xc5,0x45,0xd2,0xd7,0x2e,0x12,0x10,
0xe,0xe0,0x38,0x80,0x1,0xc8,0x68,0x65,0xf3,0xae,0x56,0xb9,0x2c,0x4b,0x42,0x4f,
0x44,0x20,0x9d,0x84,0xe3,0xe2,0x1c,0x0,0xca,0x98,0xe9,0x94,0x2a,0x79,0xdd,0x36,
0x32,0x8b,0x45,0xf7,0xba,0x17,0xb0,0xab,0x50,0x95,0x85,0xa6,0x93,0x6b,0x5,0x60,
0x4f,0x5c,0xec,0x7,0x7,0xcc,0x5b,0x14,0xf,0x3d,0x86,0x89,0xe5,0xb2,0x7e,0x75,
0x56,0x3f,0x1d,0xbc,0xaf,0xc,0xb5,0x32,0x70,0xab,0x6a,0xa,0xb0,0x23,0xcc,0xf7,
0x15,0x5d,0x6,0x8f,0x1,0x77,0xa,0x96,0x76,0x6d,0xb6,0xf8,0x2a,0x53,0x95,0xd1,
0xad,0x34,0x5f,0x17,0x40,0xa,0xf1,0x7d,0x1e,0x3,0x6e,0xdd,0x33,0x97,0x7f,0x9b,
0x2f,0xbd,0xf2,0xf8,0xe9,0xdd,0x5e,0x80,0x54,0x5a,0x8e,0x89,0x64,0xcf,0x8d,0x9c,
0xb1,0x34,0x9c,0x35,0x4e,0x42,0x55,0x26,0xb7,0xc3,0xbc,0x39,0x0,0xd0,0x97,0xd1,
0x2a,0x73,0xf3,0xba,0x73,0x12,0xaa,0x32,0xb3,0x5d,0xe6,0xeb,0x1,0x90,0x79,0xdd,
0x39,0xde,0xea,0x49,0xfe,0x5f,0xeb,0x4f,0x5a,0x83,0xf0,0x1e,0x16,0x99,0x6e,0xc2,
0x0,0x0,0x0,0x0,0x49,0x45,0x4e,0x44,0xae,0x42,0x60,0x82,
};
static const unsigned char qt_resource_name[] = {
// images
0x0,0x6,
0x7,0x3,0x7d,0xc3,
0x0,0x69,
0x0,0x6d,0x0,0x61,0x0,0x67,0x0,0x65,0x0,0x73,
// about.png
0x0,0x9,
0x6,0xc7,0x98,0x67,
0x0,0x61,
0x0,0x62,0x0,0x6f,0x0,0x75,0x0,0x74,0x0,0x2e,0x0,0x70,0x0,0x6e,0x0,0x67,
};
static const unsigned char qt_resource_struct[] = {
// :
0x0,0x0,0x0,0x0,0x0,0x2,0x0,0x0,0x0,0x1,0x0,0x0,0x0,0x1,
// :/images
0x0,0x0,0x0,0x0,0x0,0x2,0x0,0x0,0x0,0x1,0x0,0x0,0x0,0x2,
// :/images/about.png
0x0,0x0,0x0,0x12,0x0,0x0,0x0,0x0,0x0,0x1,0x0,0x0,0x0,0x0,
};
QT_BEGIN_NAMESPACE
extern Q_CORE_EXPORT bool qRegisterResourceData
(int, const unsigned char *, const unsigned char *, const unsigned char *);
extern Q_CORE_EXPORT bool qUnregisterResourceData
(int, const unsigned char *, const unsigned char *, const unsigned char *);
QT_END_NAMESPACE
int QT_MANGLE_NAMESPACE(qInitResources_qrcexample)()
{
QT_PREPEND_NAMESPACE(qRegisterResourceData)
(0x01, qt_resource_struct, qt_resource_name, qt_resource_data);
return 1;
}
Q_CONSTRUCTOR_FUNCTION(QT_MANGLE_NAMESPACE(qInitResources_qrcexample))
int QT_MANGLE_NAMESPACE(qCleanupResources_qrcexample)()
{
QT_PREPEND_NAMESPACE(qUnregisterResourceData)
(0x01, qt_resource_struct, qt_resource_name, qt_resource_data);
return 1;
}
Q_DESTRUCTOR_FUNCTION(QT_MANGLE_NAMESPACE(qCleanupResources_qrcexample))
1.直接将qrc也删除，然后再建一个qrc，系统会自动生成相应的qrc_*.cpp文件。如果是一个解决方案中含有多个项目时，可能会失败，我就遇到这个问题。
2.如果是一个解决方案中的多个项目，建议将该项目独立打开，然后将qrc删除，然后再添加qrc。我是这样解决的。
另外，在引用qrc资源时要注意，是:/prefix/images/xxx.png.其中冒号是必须的，表明是引用的路径。/prefix是qrc资源文件中设置的前缀。images/xxx.png，是该图片对应qrc的相对路径。当然也可以将/prefix直接换成/，这样引用会方便一点(:/images/xxx.png)。下面是qrc的代码。
images/about.png