突然出现了这样问题，吓死我，然后只是把原来编译好的
app里面所有的东西删除再编译就好了。
如果删除后不行，可以试试后面的截图所说，反正我是没有试过的
Starting /Qtwork/build-test1-Desktop_Qt_5_4_2_clang_64bit-Release/test1.app/Contents/MacOS/test1...
objc[17277]: Class NotificationReceiver is implemented in both /Qt5.4.2/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets and /Qtwork/build-test1-Desktop_Qt_5_4_2_clang_64bit-Release/test1.app/Contents/Frameworks/QtWidgets.framework/Versions/5/QtWidgets.
One of the two will be used. Which one is undefined.
QObject::moveToThread: Current thread (0x7f9c8160c740) is not the object's thread (0x7f9c81510670).
Cannot move to target thread (0x7f9c8160c740)
You might be loading two sets of Qt binaries into the same process. Check that all plugins are compiled against the right Qt binaries. Export DYLD_PRINT_LIBRARIES=1 and check that only one
set of binaries are being loaded.
This application failed to start because it could not find or load the Qt platform plugin "cocoa".
Available platform plugins are: cocoa.
Reinstalling the application may fix this problem.
程序异常结束。
/Qtwork/build-test1-Desktop_Qt_5_4_2_clang_64bit-Release/test1.app/Contents/MacOS/test1 crashed
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