问题
I have gotten the latest QWT 5.1.2 for QT 4.5 and managed to get it to complie. I am now trying to get the plugin to work in QT Designer (with VS intergration). I have placed the plugin files into the plugin/designer folder, but when attempting to load, I hit this error
Cannot load library qwt_desginer_plugin5.dll: The specified module cannot be found.
I've done some search on this issue, one page which suggest moving the plugin to the VS intergration folder - which does not exist for Program Files\Nokia\Vs4Addin.
My QT Designer is a debug-and-relase build. (That is, if I use a debug build of the plugin it would complain that it is expecting a release).
回答1:
qwt_designer_plugin5.dll depends on qwt5.dll, so:
Additionally to placing "qwt_desginer_plugin5.dll" in "plugins\designer" directory, you must put qwt5.dll to some place where windows loader can find it (at example, you can put it in "%QTDIR%\bin" directory)
回答2:
It appears that I have to place the generated dll into the qt\bin folder for the designer to load the plugin
回答3:
You may place it everywhere in the PATH. Also the same dir as the executable program works. You can see how dll libraries are loaded.
来源：https://stackoverflow.com/questions/1436628/qwt-plugin-for-qt-4-5