приложение принудительно закрывается, когда я нажимаю кнопку

Question

Приложение закрывается, когда я нажимаю кнопку печати на панели инструментов. Думаю, я поставил код в неправильном месте? Может быть, код неправильный? или что-то еще ...

MainActivity.java:

package com.vvhvb.hesselfeenstra.vvheerenveenseboys; 

import android.content.Intent; 
import android.os.Bundle; 
import android.support.design.widget.FloatingActionButton; 
import android.support.design.widget.Snackbar; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 
import android.view.View; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.webkit.WebView; 
import android.widget.Button; 

public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     String url ="http://dehvb.nl/"; 
     WebView view=(WebView) this.findViewById(R.id.webView); 
     view.getSettings().setJavaScriptEnabled(true); 
     view.getSettings().setBuiltInZoomControls(true); 
     view.getSettings().setDisplayZoomControls(false); 
     view.loadUrl(url); 

    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.menu_main, menu); 

     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     Button btnSimple = (Button) findViewById(R.id.action_about); 
     btnSimple.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

       Intent intent = new Intent(v.getContext(), about.class); 
       startActivityForResult(intent, 0); 
      } 
     }); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_about) { 
      return true; 


     } 

     return super.onOptionsItemSelected(item); 
    } 
} 

about.java

package com.vvhvb.hesselfeenstra.vvheerenveenseboys; 


import android.app.Activity; 
import android.os.Bundle; 

public class about extends Activity { 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.about); 

    } 


} 

Logcat:

06-12 11:53:10.441 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/WebViewFactory: Loading com.google.android.webview version 50.0.2661.86 (code 266108600) 
06-12 11:53:10.441 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys W/ResourcesManager: getTopLevelResources: /data/app/com.google.android.webview-2/base.apk/1.0 running in com.vvhvb.hesselfeenstra.vvheerenveenseboys rsrc of package com.google.android.webview 
06-12 11:53:10.451 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/ResourcesManager: For user 0 new overlays fetched Null 
06-12 11:53:10.451 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/InjectionManager: Inside getClassLibPath caller 
06-12 11:53:10.461 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/cr_LibraryLoader: Time to load native libraries: 2 ms (timestamps 9936-9938) 
06-12 11:53:10.461 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/cr_LibraryLoader: Expected native library version number "50.0.2661.86", actual native library version number "50.0.2661.86" 
06-12 11:53:10.471 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys V/WebViewChromiumFactoryProvider: Binding Chromium to main looper Looper (main, tid 1) {bde8c1c} 
06-12 11:53:10.471 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/cr_LibraryLoader: Expected native library version number "50.0.2661.86", actual native library version number "50.0.2661.86" 
06-12 11:53:10.471 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/chromium: [INFO:library_loader_hooks.cc(143)] Chromium logging enabled: level = 0, default verbosity = 0 
06-12 11:53:10.501 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/cr_BrowserStartup: Initializing chromium process, singleProcess=true 
06-12 11:53:10.511 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys E/ApkAssets: Error while loading asset assets/natives_blob_64.bin: java.io.FileNotFoundException: assets/natives_blob_64.bin 
06-12 11:53:10.511 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys E/ApkAssets: Error while loading asset assets/snapshot_blob_64.bin: java.io.FileNotFoundException: assets/snapshot_blob_64.bin 
06-12 11:53:10.521 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/libEGL: loaded /vendor/lib/egl/libGLES_mali.so 
06-12 11:53:10.551 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/libEGL: eglInitialize EGLDisplay = 0xffccd144 
06-12 11:53:10.611 15392-15527/com.vvhvb.hesselfeenstra.vvheerenveenseboys W/cr_media: Requires BLUETOOTH permission 
06-12 11:53:10.631 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/art: Rejecting re-init on previously-failed class java.lang.Class<com.android.webview.chromium.WebViewContentsClientAdapter$WebResourceErrorImpl> 
06-12 11:53:10.631 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/art: Rejecting re-init on previously-failed class java.lang.Class<com.android.webview.chromium.WebViewContentsClientAdapter$WebResourceErrorImpl> 
06-12 11:53:10.681 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/art: Rejecting re-init on previously-failed class java.lang.Class<org.chromium.content.browser.FloatingWebActionModeCallback> 
06-12 11:53:10.691 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/art: Rejecting re-init on previously-failed class java.lang.Class<org.chromium.content.browser.FloatingWebActionModeCallback> 
06-12 11:53:10.711 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/cr_Ime: [InputMethodManagerWrapper.java:30] Constructor 
06-12 11:53:10.731 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys W/cr_AwContents: onDetachedFromWindow called when already detached. Ignoring 
06-12 11:53:10.731 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/cr_Ime: [InputMethodManagerWrapper.java:59] isActive: false 
06-12 11:53:10.791 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/cr_Ime: ImeThread is not enabled. 
06-12 11:53:10.801 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/Activity: performCreate Call Injection manager 
06-12 11:53:10.801 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/InjectionManager: dispatchOnViewCreated > Target : com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity isFragment :false 
06-12 11:53:10.811 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true 
06-12 11:53:10.811 15392-15572/com.vvhvb.hesselfeenstra.vvheerenveenseboys E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY) 
06-12 11:53:10.811 15392-15572/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/libEGL: eglInitialize EGLDisplay = 0xde341864 
06-12 11:53:10.831 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/PhoneWindow: *FMB* isFloatingMenuEnabled mFloatingMenuBtn : null 
06-12 11:53:10.831 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/PhoneWindow: *FMB* isFloatingMenuEnabled return false 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/libEGL: eglInitialize EGLDisplay = 0xde43fc54 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/OpenGLRenderer: Initialized EGL, version 1.4 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/OpenGLRenderer: HWUI protection enabled for context , &this =0xf4f12490 ,&mEglDisplay = 1 , &mEglConfig = -185306468 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/OpenGLRenderer: Get maximum texture size. GL_MAX_TEXTURE_SIZE is 8192 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/OpenGLRenderer: Enabling debug mode 0 
06-12 11:53:10.891 15392-15571/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/mali_winsys: new_window_surface returns 0x3000, [1080x1920]-format:1 
06-12 11:53:11.101 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/InjectionManager: dispatchCreateOptionsMenu :com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity 
06-12 11:53:11.101 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/InjectionManager: dispatchPrepareOptionsMenu :com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity 
06-12 11:53:11.271 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@3253f19b time:6070740 
06-12 11:53:11.501 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys W/cr_BindingManager: Cannot call determinedVisibility() - never saw a connection for the pid: 15392 
06-12 11:53:11.511 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/cr_Ime: [InputMethodManagerWrapper.java:59] isActive: true 
06-12 11:53:11.511 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/cr_Ime: [InputMethodManagerWrapper.java:68] hideSoftInputFromWindow 
06-12 11:53:16.391 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/ViewRootImpl: ViewPostImeInputStage ACTION_DOWN 
06-12 11:53:16.471 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/InjectionManager: dispatchOptionsItemSelected :com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity 
06-12 11:53:16.481 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys D/AndroidRuntime: Shutting down VM 
06-12 11:53:16.481 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys E/AndroidRuntime: FATAL EXCEPTION: main 
                          Process: com.vvhvb.hesselfeenstra.vvheerenveenseboys, PID: 15392 
                          java.lang.ClassCastException: android.support.v7.view.menu.ActionMenuItemView cannot be cast to android.widget.Button 
                           at com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity.onOptionsItemSelected(MainActivity.java:48) 
                           at android.app.Activity.onMenuItemSelected(Activity.java:3201) 
                           at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:403) 
                           at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:189) 
                           at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:100) 
                           at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:100) 
                           at android.support.v7.app.ToolbarActionBar$2.onMenuItemClick(ToolbarActionBar.java:69) 
                           at android.support.v7.widget.Toolbar$1.onMenuItemClick(Toolbar.java:169) 
                           at android.support.v7.widget.ActionMenuView$MenuBuilderCallback.onMenuItemSelected(ActionMenuView.java:760) 
                           at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811) 
                           at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152) 
                           at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958) 
                           at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:948) 
                           at android.support.v7.widget.ActionMenuView.invokeItem(ActionMenuView.java:618) 
                           at android.support.v7.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:139) 
                           at android.view.View.performClick(View.java:5246) 
                           at android.widget.TextView.performClick(TextView.java:10604) 
                           at android.view.View$PerformClick.run(View.java:21256) 
                           at android.os.Handler.handleCallback(Handler.java:739) 
                           at android.os.Handler.dispatchMessage(Handler.java:95) 
                           at android.os.Looper.loop(Looper.java:145) 
                           at android.app.ActivityThread.main(ActivityThread.java:6917) 
                           at java.lang.reflect.Method.invoke(Native Method) 
                           at java.lang.reflect.Method.invoke(Method.java:372) 
                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 
06-12 11:53:19.991 15392-15392/com.vvhvb.hesselfeenstra.vvheerenveenseboys I/Process: Sending signal. PID: 15392 SIG: 9 

about.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

</RelativeLayout> 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> 
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:context="com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity"> 

    <android.support.design.widget.AppBarLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:theme="@style/AppTheme.AppBarOverlay"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      android:background="?attr/colorPrimary" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

    <include layout="@layout/content_main" /> 

</android.support.design.widget.CoordinatorLayout> 

content_main.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" 
    tools:context="com.vvhvb.hesselfeenstra.vvheerenveenseboys.MainActivity" 
    tools:showIn="@layout/activity_main"> 

    <WebView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/webView" 
     android:layout_alignParentBottom="true" 
     android:layout_alignParentRight="true" 
     android:layout_alignParentEnd="true" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" /> 
</RelativeLayout> 

Я надеюсь, что кто-нибудь может помочь мне с этой проблемой.

Answer 1

Вы получаете класс Cast исключение в этой строке:

Button btnSimple = (Button) findViewById(R.id.action_about); 

Что это означает, что вы пытаетесь бросить то, что не является Button к Button. В вашем случае у вас есть ActionMenuItemView, а не Button.

Устранить литье к правильному типу, как:

ActionMenuItemView btnSimple = (ActionMenuItemView) findViewById(R.id.action_about); 

И изменив логику onClickListener, проверить, какие методы ActionMenuItemView есть.

Answer 2

Поместите код кнопки в методе OnCreate вместо optionmenu

Answer 3

Если идентификатор принадлежит к вашему menu.xml, то вы должны сделать следующее:

@Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
      getMenuInflater().inflate(R.menu. menu_main, menu); 
    } 

Теперь никакой пользы setOnClickListener, просто использовать:

public boolean onOptionsItemSelected(MenuItem item) { 
     if(item.getItemId() == R.id.action_about){ 
      Intent intent = new Intent(getContext(), about.class); 
      startActivityForResult(intent, 0); 
     } 
     return super.onOptionsItemSelected(item); 
    } 

Надеется, что это будет работать для вас :)

Answer 4

android.support.v7.view.menu.ActionMenuItemView cannot be cast to android.widget.Button 

Как говорится, вы не можете нанести элемент панели действий на кнопку. Так удалить это:

Button btnSimple = (Button) findViewById(R.id.action_about); 
     btnSimple.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

       Intent intent = new Intent(v.getContext(), about.class); 
       startActivityForResult(intent, 0); 
      } 
     }); 

и положить его в методе OnCreate. Если он по-прежнему падает, затем снова выведите лог-код. Это должно измениться. Если вы пытаетесь добавить элемент меню, следуйте этому руководству: https://developer.android.com/training/appbar/index.html