参考QT Designer文档的第一个例子，使用QT Designer做的界面，生成.h和.cpp文件，但链接时出现以下编译错误，是什么问题呢？
Makefile:120: warning: overriding commands for target `moc_PizzaEntryForm.cpp'
Makefile:117: warning: ignoring old commands for target `moc_PizzaEntryForm.cpp'g++ -c -pipe -DQWS -fno-exceptions -fno-rtti -Wall -W -O2 -DNO_DEBUG -I/study/qt/x86-qtopia/qt/include -o main.o main.cpp
/study/qt/x86-qtopia/qt/bin/moc PizzaEntryForm.h -o moc_PizzaEntryForm.cpp
g++ -c -pipe -DQWS -fno-exceptions -fno-rtti -Wall -W -O2 -DNO_DEBUG -I/study/qt/x86-qtopia/qt/include -o moc_PizzaEntryForm.o moc_PizzaEntryForm.cpp
gcc -o chap1 PizzaEntryForm.o main.o PizzaEntryForm.o moc_PizzaEntryForm.o moc_PizzaEntryForm.o -L/study/qt/x86-qtopia/qt/lib -lqte -lm -lstdc++
PizzaEntryForm.o(.text+0x0): In function `PizzaEntryForm::PizzaEntryForm[not-in-charge](QWidget*, char const*, bool, unsigned)':
: multiple definition of `PizzaEntryForm::PizzaEntryForm[not-in-charge](QWidget*, char const*, bool, unsigned)'
PizzaEntryForm.o(.text+0x0): first defined here
PizzaEntryForm.o(.text+0x964): In function `PizzaEntryForm::PizzaEntryForm[in-charge](QWidget*, char const*, bool, unsigned)':
: multiple definition of `PizzaEntryForm::PizzaEntryForm[in-charge](QWidget*, char const*, bool, unsigned)'
PizzaEntryForm.o(.text+0x964): first defined here
PizzaEntryForm.o(.text+0x12c8): In function `PizzaEntryForm::~PizzaEntryForm [not-in-charge]()':
: multiple definition of `PizzaEntryForm::~PizzaEntryForm [not-in-charge]()'
PizzaEntryForm.o(.text+0x12c8): first defined here
PizzaEntryForm.o(.text+0x12ec): In function `PizzaEntryForm::~PizzaEntryForm [in-charge]()':
: multiple definition of `PizzaEntryForm::~PizzaEntryForm [in-charge]()'
PizzaEntryForm.o(.text+0x12ec): first defined here
PizzaEntryForm.o(.text+0x1310): In function `PizzaEntryForm::~PizzaEntryForm [in-charge deleting]()':
: multiple definition of `PizzaEntryForm::~PizzaEntryForm [in-charge deleting]()'
PizzaEntryForm.o(.text+0x1310): first defined here
moc_PizzaEntryForm.o(.text+0x0): In function `PizzaEntryForm::className() const':
: multiple definition of `PizzaEntryForm::className() const'
moc_PizzaEntryForm.o(.text+0x0): first defined here
moc_PizzaEntryForm.o(.data+0x0): multiple definition of `PizzaEntryForm::metaObj'
moc_PizzaEntryForm.o(.data+0x0): first defined here
moc_PizzaEntryForm.o(.text+0xc): In function `PizzaEntryForm::initMetaObject()':: multiple definition of `PizzaEntryForm::initMetaObject()'
moc_PizzaEntryForm.o(.text+0xc): first defined here
moc_PizzaEntryForm.o(.text+0xcc): In function `PizzaEntryForm::staticMetaObject()':
: multiple definition of `PizzaEntryForm::staticMetaObject()'
moc_PizzaEntryForm.o(.text+0xcc): first defined here
moc_PizzaEntryForm.o(.text+0x74): In function `PizzaEntryForm::tr(char const*)':: multiple definition of `PizzaEntryForm::tr(char const*)'
moc_PizzaEntryForm.o(.text+0x74): first defined here
moc_PizzaEntryForm.o(.text+0xa0): In function `PizzaEntryForm::tr(char const*, char const*)':
: multiple definition of `PizzaEntryForm::tr(char const*, char const*)'
moc_PizzaEntryForm.o(.text+0xa0): first defined here
collect2: ld returned 1 exit status
make: *** [chap1] Error 1
