Ctrl-从按钮拖动到方法不起作用。 Xcode / Interface Builder

I am building an iOS app and i have most of the code/GUI built (its a single view app). Now i have the .xib and controller.h file next to each other and I want to associate a button click with a certain action. Everytime I try nothing happens. The UI indictor that I am dragging shows up but it wont let me connect to the method. This happens for all the objects/methods.I am building an iOS app and i have most of the