In this example :qt\examples\declarative\tutorials\extending\chapt er6-plugins, it extending QML,
Qt Code:
  1. qmlRegisterType<PieChart>(uri, 1, 0, "PieChart");
  2. qmlRegisterType<PieSlice>(uri, 1, 0, "PieSlice");
To copy to clipboard, switch view to plain text mode 
it add two classes to QML, but where place the dll file? I had try some pathes, such as qt/imports and qt/plugins , they are all doesn't work.

who knows? thank you every much...