為什么我的總會(huì)崩潰？

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

at net.kdt.pojavlaunch.fragments.MainMenuFragment.onViewCreated(MainMenuFragment.java:70)

at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2987)

at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:546)

at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)

at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)

at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1647)

at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3128)

at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3072)

at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:251)

at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:502)

at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:210)

at net.kdt.pojavlaunch.LauncherActivity.onStart(LauncherActivity.java:206)

at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1529)

at android.app.Activity.performStart(Activity.java:8447)

at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3901)

at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)

at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)

at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)

at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2474)

at android.os.Handler.dispatchMessage(Handler.java:106)

at android.os.Looper.loopOnce(Looper.java:240)

at android.os.Looper.loop(Looper.java:351)

at android.app.ActivityThread.main(ActivityThread.java:8422)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:584)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1013)