java - 当我运行应用程序时，构建成功但应用程序崩溃。请帮帮我。以下是我在运行选项卡中收到的错误

Question

189) 在 com.android.volley.toolbox.HurlStack.openConnection(HurlStack.java:207) 在 com.android.volley.toolbox.HurlStack.executeRequest(HurlStack.java:88) 在 com.android.volley.toolbox.BasicNetwork .performRequest(BasicNetwork.java:123) 在 com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:131) 在 com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:111) 在 com.android.volley。 NetworkDispatcher.run(NetworkDispatcher.java:90) I/Process：发送信号。PID：26685 SIG：9 processRequest(NetworkDispatcher.java:131) at com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:111) at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:90) I/Process：发送信号。PID：26685 SIG：9 processRequest(NetworkDispatcher.java:131) at com.android.volley.NetworkDispatcher.processRequest(NetworkDispatcher.java:111) at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:90) I/Process：发送信号。PID：26685 SIG：9

标签： javaandroidxmlandroid-studiodebugging

Answer 1

当您设置布局管理器 RecyclerView 实例为空时：

ava.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.recyclerview.widget.RecyclerView.setLayoutManager(androidx.recyclerview.widget.RecyclerView$LayoutManager)' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)