Class CalendarModel is implemented in both /Users/zhongqihulian/Library/Developer/CoreSimulator/Devices/5827D04B-BADE-4213-B278-4DE0EFC329ED/data/Containers/Bundle/Application/EE52F2FE-7D17-499B-9274-7FB1E68473F7/XYFrameWork.app/XYFrameWork and /Applications/Xcode_7.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/Frameworks/EventKitUI.framework/EventKitUI. One of the two will be used. Which one is undefined.
solve:
Set "Bundle Loader" correctly to $(BUILT_PRODUCTS_DIR)/AppName.app/AppName Set "Symbols Hidden by Default" to NO (in Build Settings of the target application). This is where the linker errors come from because it is YES by default!. I've been struggling with this for so long!.
无效 其实是 CalendarModel 与系统的 日历库EventKitUI 命名冲突 但为什么 出现 还未发现