小编ryc*_*zai的帖子

我试图在共享偏好中保存玩家的名字,并通过在共享偏好中再次获取它而使其显示在另一个活动中但我的应用程序崩溃.

致命异议:主要

 Process: plp.cs4b.thesis.drawitapp, PID: 1970
 java.lang.RuntimeException: Unable to start activity ComponentInfo{plp.cs4b.thesis.drawitapp/plp.cs4b.thesis.drawitapp.PlayGame}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String plp.cs4b.thesis.drawitapp.Player.getName()' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
    at android.app.ActivityThread.access$800(ActivityThread.java:144)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5221)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String plp.cs4b.thesis.drawitapp.Player.getName()' on a null object reference
    at plp.cs4b.thesis.drawitapp.PlayGame.onCreate(PlayGame.java:20)
    at android.app.Activity.performCreate(Activity.java:5933)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
    ... 10 more

代码:

Player.java

public class Player { …