. lang。IllegalStateException:无法在Android Studio中找到button的onClick方法

I am building an app named Ping in Android Studio. So far my activities are LoginActivity ProfileActivity and Timeline. My issue is that a button in the layout corresponding to the Timeline activity has an onClick method that isn't working. When the button is clicked, the emulator gives the "Unfortunatley, Ping has stopped." I'm defining the buttons and onClick methods the same way I have for other buttons whose functions are working, just this one does not seem to work. I'm receiving an error saying the method can't be found, but I've written the method in the corresponding activity. Here is the logcat:I am building an app named Ping in Android Stud