尝试调用虚拟方法的java.lang。对象:空对象引用上的android.content.Context.getSystemService(java.lang.String)'

I am trying to check if my application is launched for the first time. If yes, the user is asked for an input. Then, check if Wi-Fi is connected. If Wi-Fi is connected, I use the input provides by the user to load a WebView.I am trying to check if my application is launc