在该项目的Build Phases －> Compile Soureces 对不想使用arc的编译的源文件加上 -fno-objc-arc 即可

  please note, this is not a sequence of steps. each one is a possible solution: 1- restart xcode and/or restart simulator (reset content and settings) and/or restart computer. 2- click on project name in project navigator. in build settings tab, go to pa…