尝试使用if语句设置图像资源时强制关闭

Hello my professor cannot figure this out so I figured I would post here. I am trying to make an app that shows temperatures and when the seek bar gets to a certain temp I want to have a different image appear in an imageView. When i test the app and the seek bar gets past 40 the app forecloses. Can anyone tell me why that is?Hello my professor cannot figure this out so I