的Android开始新的活动错误

我需要一些代码帮助，出于某种原因，我不能启动新的活动里面的“onNavigationDrawerItemSelected”的Android开始新的活动错误

这是我的MainActivity：

package com.spadramatico; 

import android.content.Intent; 
import android.os.Bundle; 
import android.support.v4.widget.DrawerLayout; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.widget.Toast; 


public class MainActivity extends AppCompatActivity 
     implements NavigationDrawerCallbacks { 

    /** 
    * Fragment managing the behaviors, interactions and presentation of the navigation drawer. 
    */ 
    private NavigationDrawerFragment mNavigationDrawerFragment; 
    private Toolbar mToolbar; 

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

     mNavigationDrawerFragment = (NavigationDrawerFragment) 
       getFragmentManager().findFragmentById(R.id.fragment_drawer); 

     // Set up the drawer. 
     mNavigationDrawerFragment.setup(R.id.fragment_drawer, (DrawerLayout) findViewById(R.id.drawer), mToolbar); 
    } 

    @Override 
    public void onNavigationDrawerItemSelected(int position) { 
     // update the main content by replacing fragments 
     Toast.makeText(this, "Menu item selected -> " + position, Toast.LENGTH_SHORT).show(); 



     if(position == 1) { 

      Intent i=new Intent(MainActivity.this, spadramaticoActivity.class); 
      startActivity(i); 

     } 


    } 



    @Override 
    public void onBackPressed() { 
     if (mNavigationDrawerFragment.isDrawerOpen()) 
      mNavigationDrawerFragment.closeDrawer(); 
     else 
      super.onBackPressed(); 
    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     if (!mNavigationDrawerFragment.isDrawerOpen()) { 
      // Only show items in the action bar relevant to this screen 
      // if the drawer is not showing. Otherwise, let the drawer 
      // decide what to show in the action bar. 
      getMenuInflater().inflate(R.menu.main, menu); 
      return true; 
     } 
     return super.onCreateOptionsMenu(menu); 
    } 


    @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(); 

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

     return super.onOptionsItemSelected(item); 
    } 


}

这是我spadramaticoActivity.class

package com.spadramatico; 

import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 


/** 
* Created by IvoMi on 15/10/2015. 
*/ 
public class spadramaticoActivity extends AppCompatActivity { 

    private Toolbar toolbar; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.meu_spadramatico_fragment); 

     toolbar = (Toolbar) findViewById(R.id.toolbar_actionbar); 
     setSupportActionBar(toolbar); 
     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
    } 
}

这是错误：

10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime: FATAL EXCEPTION: main 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime: Process: com.spadramatico, PID: 2165 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.spadramatico/com.spadramatico.spadramaticoFragment}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on a null object reference 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.-wrap11(ActivityThread.java) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.os.Handler.dispatchMessage(Handler.java:102) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:148) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.main(ActivityThread.java:5417) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native Method) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.support.v7.widget.Toolbar.getTitle()' on a null object reference 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:100) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:93) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.support.v7.internal.app.ToolbarActionBar.<init>(ToolbarActionBar.java:78) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:204) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:99) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at com.spadramatico.spadramaticoFragment.onCreate(spadramaticoFragment.java:27) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.Activity.performCreate(Activity.java:6237) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.-wrap11(ActivityThread.java)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.os.Handler.dispatchMessage(Handler.java:102)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.os.Looper.loop(Looper.java:148)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at android.app.ActivityThread.main(ActivityThread.java:5417)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at java.lang.reflect.Method.invoke(Native Method)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
10-15 11:36:03.816 2165-2165/com.spadramatico E/AndroidRuntime:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

我看到其他计算器问题，我understant，我需要有清单，以及这些活动..

这是我的AndroidManifest.xml：

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.spadramatico" > 

    <application 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:label="@string/app_name" 
     android:supportsRtl="true" 
     android:theme="@style/AppTheme" > 


     <activity 
      android:name=".MainActivity" 
      android:label="@string/app_name" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 

     <activity android:name=".spadramaticoActivity" 
      android:label="@string/app_name" 
      android:parentActivityName=".MainActivity"> 

      <meta-data 
       android:name="android.support.PARENT_ACTIVITY" 
       android:value="com.spadramatico.MainActivity"> 

      </meta-data> 
     </activity> 

    </application> 

</manifest>

谁能告诉我做什么我错了我该如何解决它？谢谢你们！

来源

2015-10-15 user3000019

*请分享 “spadramaticoFragment.java”。 'meu_spadramatico_fragment'中是否存在'toolbar_actionbar'布局？ – karthik

？ –

哦，上帝，我真的不知道我怎么跳了这一行：显示java.lang.NullPointerException：尝试在空调用虚拟方法java.lang.CharSequence中android.support.v7.widget.Toolbar.getTitle（）“所致对象引用谢谢...真的，我认为它的压力，我需要得到这个工作的今天。谢谢！ – user3000019

对于我来说，看来你是在膨胀的onCreate错误的布局，即setContentView(R.layout.meu_spadramatico_fragment)。你在扩大片段布局，而不是你想要进行活动的那个。我猜在这个片段布局中没有工具栏，因此工具栏为空。这就是错误所说的。

来源

2015-10-15 11:56:29

欢迎您。随意接受，如果它的作品。否则，我会帮助解决这个问题。 –

的Android开始新的活动错误

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