Qt的編程中包含了插件模式，使得程序的擴展性非常好，但插件的動態加載的檢查也比較嚴格，這次編譯數據庫驅動插件就碰到了不少問題。實際上，可以在系統的 環境變量中設置QT_DEBUG_PLUGINS＝1 ，即在終端中執行 export QT_DEBUG_PLUGINS=1
再執行程序加載插件時，再系統控制台上會輸出許多加載插件時的調試信息，可以清楚的看到系統嘗試加載了哪些插件，哪些是成功的，哪些沒有成功，原因是什么都寫的比較清楚。因此，如果自己編譯的插件庫無法加載，可以用這個方式檢查以下到底是哪里的問題。
//-------------------------------------
在沒有添加QT_DEBUG_PLUGINS＝1時，運行程序：
Open: "/dev/ttyO1"
Open: "/dev/ttyO4"
+++++++++++++++++++++++++++++++++++++++++++++++++++.
++++++++++++++++++++++++Create Command Thread.....
+++++++++++++++++++++++++++++++++++++++++++++++++++.
defaultServiceProvider::requestService(): no service found for - "org.qt-project
.qt.audiosource"
Input Devices Can Used :
()
===========
Default Input Devices :
""
-------------------
Encoder:
//-------------------------------------
添加QT_DEBUG_PLUGINS＝1(即在即在終端中執行 export QT_DEBUG_PLUGINS=1)
//-------------------------------------
Open: "/dev/ttyO1"
Open: "/dev/ttyO3"
Open: "/dev/ttyO4"
QFactoryLoader::QFactoryLoader() checking directory path "/workspace/mediaservic
e" ...
QFactoryLoader::QFactoryLoader() looking at "/workspace/mediaservice/libqtmedia_
audioengine.so"
+++++++++++++++++++++++++++++++++++++++++++++++++++.
++++++++++++++++++++++++Create Command Thread.....
+++++++++++++++++++++++++++++++++++++++++++++++++++.
QElfParser: '/workspace/mediaservice/libqtmedia_audioengine.so' is an invalid EL
F object (string table seems to be at a100)
"'/workspace/mediaservice/libqtmedia_audioengine.so' is an invalid ELF object (s
tring table seems to be at a100)"
not a plugin
defaultServiceProvider::requestService(): no service found for - "org.qt-project
.qt.audiosource"
Input Devices Can Used :
()
===========
Default Input Devices :
""
-------------------
可以看到 提示的更詳細，libqtmedia_audioengine.so 有問題，再排查吧
果然 重新換一下這個so 再運行 就正常了。。。