操作系統：Ubuntu12.04
QT版本：4.8.5
由於系統原因，今天要重新編譯QT，在編譯PC版的qvfb的make步驟時，出現了如下錯誤：
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriter::QAnimationWriter(QString const&, char const*)':
qanimationwriter.cpp:(.text+0xbf): undefined reference to `png_create_write_struct'
qanimationwriter.cpp:(.text+0xca): undefined reference to `png_create_info_struct'
qanimationwriter.cpp:(.text+0xe0): undefined reference to `png_set_compression_level'
qanimationwriter.cpp:(.text+0xff): undefined reference to `png_set_write_fn'
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriterMNG::write(png_struct_def*, unsigned char*, unsigned int)':
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG5writeEP14png_struct_defPhj[QAnimationWriterMNG::write(png_struct_def*, unsigned char*, unsigned int)]+0xb): undefined reference to `png_get_io_ptr'
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)':
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x65): undefined reference to `png_write_chunk'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x78): undefined reference to `png_set_sig_bytes'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0xda): undefined reference to `png_set_IHDR'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0xec): undefined reference to `png_write_info'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x107): undefined reference to `png_set_bgr'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x154): undefined reference to `png_write_image'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x172): undefined reference to `png_write_end'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x184): undefined reference to `png_destroy_write_struct'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x1a8): undefined reference to `png_create_write_struct'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x1b3): undefined reference to `png_create_info_struct'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x1c9): undefined reference to `png_set_compression_level'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x1e8): undefined reference to `png_set_write_fn'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG12composeImageERK6QImageRK6QPoint[QAnimationWriterMNG::composeImage(QImage const&, QPoint const&)]+0x21f): undefined reference to `png_set_filler'
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriterMNG::~QAnimationWriterMNG()':
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD0Ev[_ZN19QAnimationWriterMNGD5Ev]+0x9e): undefined reference to `png_write_chunk'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD0Ev[_ZN19QAnimationWriterMNGD5Ev]+0xb0): undefined reference to `png_destroy_write_struct'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD0Ev[_ZN19QAnimationWriterMNGD5Ev]+0x176): undefined reference to `png_write_chunk'
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriterMNG::setImage(QImage const&)':
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNG8setImageERK6QImage[QAnimationWriterMNG::setImage(QImage const&)]+0xc3): undefined reference to `png_write_chunk'
.obj/release-shared/qanimationwriter.o: In function `QAnimationWriterMNG::~QAnimationWriterMNG()':
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD2Ev[_ZN19QAnimationWriterMNGD5Ev]+0x9e): undefined reference to `png_write_chunk'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD2Ev[_ZN19QAnimationWriterMNGD5Ev]+0xb0): undefined reference to `png_destroy_write_struct'
qanimationwriter.cpp:(.text._ZN19QAnimationWriterMNGD2Ev[_ZN19QAnimationWriterMNGD5Ev]+0x16e): undefined reference to `png_write_chunk'
collect2: ld 返回 1
make: *** [../../bin/qvfb] 錯誤 1
截圖如下：
解決辦法：
第一步：#locate libpng
我的電腦顯示如下：
/lib/i386-linux-gnu/libpng12.so.0
/lib/i386-linux-gnu/libpng12.so.0.46.0
/usr/share/doc/libpng12-0
/usr/share/doc/libpng12-0/ANNOUNCE
/usr/share/doc/libpng12-0/KNOWNBUG
/usr/share/doc/libpng12-0/README.Debian
/usr/share/doc/libpng12-0/README.gz
/usr/share/doc/libpng12-0/TODO
/usr/share/doc/libpng12-0/changelog.Debian.gz
/usr/share/doc/libpng12-0/copyright
/usr/share/doc/libpng12-0/libpng-1.2.46.txt.gz
/usr/share/doc-base/libpng12
/var/lib/doc-base/documents/libpng12
/var/lib/dpkg/info/libpng12-0:i386.list
/var/lib/dpkg/info/libpng12-0:i386.md5sums
/var/lib/dpkg/info/libpng12-0:i386.postinst
/var/lib/dpkg/info/libpng12-0:i386.postrm
/var/lib/dpkg/info/libpng12-0:i386.shlibs
第二步：建立鏈接#ln -s /lib/i386-linux-gnu/libpng12.so.0 /lib/i386-linux-gnu/libpng.so
第三步：修改Makefile文件，#gedit Makefile(或者 #vi Makefile),在LIBS後面添加-L/lib/i386-linux-gnu -lpng這兩項
重新make後，成功！