我使用 QtCreator 中的项目模板“Libraries/Qt Quick 2 Extension Plugin”创建了一个测试插件作为 Qt5/QML 共享库。我的开发环境是带有 Qt-5.0.0 和 QtCreator-2.6 的 linux（详情附在底部）。
源文件（关于要点）：https ://gist.github.com/4467883
源文件默认生成，没有任何更改。项目名称是“untitled”，uri 是“com.mycompany.mycomponents”，对象类名称是“MyItem”。“/tmp/untitled”中的源文件作为 SRCDIR。
并构建它以将库文件输出为“libuntitled.so”、“qmldir”和“/tmp/untitled-build”中的一些目标文件作为DESTDIR。
$ ls /tmp/untitled-build
Makefile libuntitled.so moc_myitem.cpp
moc_myitem.o moc_untitled_plugin.cpp moc_untitled_plugin.o myitem.o
qmldir untitled_plugin.o
但是，我不能使用“/tmp/test/test.qml”中的库作为带有qmlscene命令的测试 QML 源。
$ mkdir /tmp/test; cd /tmp/test
$ vim test.qml
“test.qml”（要点）：https ://gist.github.com/4474422
$ qmlscene test.qml
它是失败的，并且QML_IMPORT_TRACE日志是：
QQmlImportDatabase::addImportPath: "/usr/lib64/qt5/qml"
QQmlImportDatabase::addImportPath: "/usr/bin"
QQmlImports(file:///tmp/test/test.qml)::addImplicitImport
QQmlImports(file:///tmp/test/test.qml)::addLibraryImport: "QtQuick" 2.0 as ""
QQmlImports(file:///tmp/test/test.qml)::importExtension: loaded "/usr/lib64/qt5/qml/QtQuick.2/qmldir"
QQmlImportDatabase::importPlugin: "QtQuick" from "/usr/lib64/qt5/qml/QtQuick.2/libqtquick2plugin.so"
file:///tmp/test/test.qml:2 module "com.mycompany.mycomponents" is not installed
并尝试“-I”选项：
$ qmlscene test.qml -I /tmp/untitled-build
那也失败了。日志是：
QQmlImportDatabase::addImportPath: "/usr/lib64/qt5/qml"
QQmlImportDatabase::addImportPath: "/usr/bin"
QQmlImportDatabase::addImportPath: "/tmp/untitled-build"
QQmlImports(file:///tmp/test/test.qml)::addImplicitImport
QQmlImports(file:///tmp/test/test.qml)::addLibraryImport: "QtQuick" 2.0 as ""
QQmlImports(file:///tmp/test/test.qml)::importExtension: loaded "/usr/lib64/qt5/qml/QtQuick.2/qmldir"
QQmlImportDatabase::importPlugin: "QtQuick" from "/usr/lib64/qt5/qml/QtQuick.2/libqtquick2plugin.so"
file:///tmp/test/test.qml:2 module "com.mycompany.mycomponents" is not installed
并尝试使用“/tmp/test/qmldir”：
$ vim /tmp/test/qmldir
“tmp/test/qmldir”（关于要点）：https ://gist.github.com/4474497
那是失败。日志：
QQmlImportDatabase::addImportPath: "/usr/lib64/qt5/qml"
QQmlImportDatabase::addImportPath: "/usr/bin"
QQmlImports(file:///tmp/test/test.qml)::addImplicitImport
QQmlImports(file:///tmp/test/test.qml)::importExtension: loaded "/tmp/test/qmldir"
QQmlImportDatabase::importPlugin: ".tmp.test" from "/tmp/untitled-build/libuntitled.so"
Module '.tmp.test' does not contain a module identifier directive - it cannot be protected from external registrations.
QQmlImports(file:///tmp/test/test.qml)::addLibraryImport: "QtQuick" 2.0 as ""
QQmlImports(file:///tmp/test/test.qml)::importExtension: loaded "/usr/lib64/qt5/qml/QtQuick.2/qmldir"
QQmlImportDatabase::importPlugin: "QtQuick" from "/usr/lib64/qt5/qml/QtQuick.2/libqtquick2plugin.so"
file:///tmp/test/test.qml:2 module "com.mycompany.mycomponents" is not installed
如何在 qmlscene（或 qmlviewer5）的测试 .qml("/tmp/test.qml") 中使用 library("/tmp/untitled-build/libuntitled.so")？
环境细节（基于 openSUSE-12.2）：
$ uname -a
Linux LH-MAIN 3.4.11-2.16-desktop #1 SMP PREEMPT Wed Sep 26 17:05:00 UTC 2012 (259fc87) x86_64 x86_64 x86_64 GNU/Linux
$ g++ --version | head -n1
g++ (SUSE Linux) 4.7.1 20120723 [gcc-4_7-branch revision 189773]
$ qmake -v
QMake version 3.0
Using Qt version 5.0.0 in /usr/lib64
$ qtcreator -version 2>&1 >/dev/null | grep "^[^ ].*" | head -n1
Qt Creator 2.6.1 based on Qt 5.0.0
$ qmlviewer5 -v
Qml debugging is enabled. Only use this in a safe environment!
Qt QML Viewer version 5.0.0
参考：