下划线写完不能显示，而且软件开始一直闪退，请问怎么解决
跟着写到这里的时候，line显示不出来。重新启动app后开始打不开，一直闪退，显示XXXmusicDemo keeps stopping或者 XXXmusicDemo has stopped。重启和清除缓存都不行。
这是logcat：
2019-09-30 09:28:41.319 6492-6492/? I/art: Not late-enabling -Xcheck:jni (already on)
2019-09-30 09:28:41.320 6492-6492/? W/art: Unexpected CPU variant for X86 using defaults: x86
2019-09-30 09:28:41.337 6492-6499/? E/art: Failed sending reply to debugger: Broken pipe
2019-09-30 09:28:41.337 6492-6499/? I/art: Debugger is no longer active
2019-09-30 09:28:41.337 6492-6499/? I/art: Starting a blocking GC Instrumentation
2019-09-30 09:28:41.352 6492-6492/? W/System: ClassLoader referenced unknown path: /data/app/com.example.rychinmusicdemo-1/lib/x86
2019-09-30 09:28:41.432 6492-6509/? I/OpenGLRenderer: Initialized EGL, version 1.4
2019-09-30 09:28:41.433 6492-6509/? D/OpenGLRenderer: Swap behavior 1
2019-09-30 09:28:41.433 6492-6509/? W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
2019-09-30 09:28:41.433 6492-6509/? D/OpenGLRenderer: Swap behavior 0
2019-09-30 09:28:41.439 6492-6509/? D/EGL_emulation: eglCreateContext: 0xa961f600: maj 3 min 0 rcv 3
2019-09-30 09:28:41.459 6492-6509/? D/EGL_emulation: eglMakeCurrent: 0xa961f600: ver 3 0 (tinfo 0xa767fb90)
2019-09-30 09:28:41.459 6492-6509/? E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
2019-09-30 09:28:41.460 6492-6509/? E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008824
2019-09-30 09:28:41.469 6492-6509/? D/EGL_emulation: eglMakeCurrent: 0xa961f600: ver 3 0 (tinfo 0xa767fb90)
2019-09-30 09:28:44.382 6492-6492/com.example.rychinmusicdemo D/AndroidRuntime: Shutting down VM
2019-09-30 09:28:44.383 6492-6492/com.example.rychinmusicdemo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.rychinmusicdemo, PID: 6492
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rychinmusicdemo/com.example.rychinmusicdemo.activitys.LoginActivity}: android.view.InflateException: Binary XML file line #30: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: android.view.InflateException: Binary XML file line #30: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:761)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:858)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:412)
at android.app.Activity.setContentView(Activity.java:2414)
at com.example.rychinmusicdemo.activitys.LoginActivity.onCreate(LoginActivity.java:16)
at android.app.Activity.performCreate(Activity.java:6679)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
