致命例外：主，无法启动活动ComponentInfo

Question

当我点击我的应用程序上的按钮时，我在日志上得到上述错误。我将发布发送活动和接收活动的代码。

发送活动：

private TrackerDAO dbHelper; 
private SimpleCursorAdapter dataAdapter; 

String historyString = ""; 
long idDB; 

long getlastID; 
String getAD; 
String Check; 


public static long TripID; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_history_list); 

    try{ 

    dbHelper = new TrackerDAO(this); 

    }catch(SQLException e){ 

     e.printStackTrace(); 
    } 

    dbHelper.open(); 

    displayListView(); 
} 


private void displayListView() { 

    Cursor cursor = dbHelper.fetchAllEntries(); 

    // The desired columns to be bound 
    String[] columns = new String[] { 
       DBConfiguration.KEY_NAME, 
       DBConfiguration.KEY_CITY, 
       DBConfiguration.KEY_REASON, 
       DBConfiguration.KEY_BUDGET 
       }; 
    // the XML defined views which the data will be bound to 
    int[] to = new int[]{ 
      R.id.TV_trip_name, 
      R.id.TV_city_name, 
      R.id.TV_trip_reason, 
      R.id.TV_budget,   
    }; 

    //create the adapter using the cursor pointing to the desired data 
    //as well as the layout information 

    dataAdapter = new SimpleCursorAdapter(this, R.layout.history_list_item, cursor, columns, to, 0); 

    ListView listView = (ListView) findViewById(R.id.listView_tripHistory); 
    // Assign adapter to ListView 
    listView.setAdapter(dataAdapter); 

    listView.setOnItemClickListener(new OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> listView, View view, int position, long id) { 

      intentMethod(id); 

     } 

     private void intentMethod(long ID) { 

      //Bundle basket_tripID = new Bundle(); 
      //basket_tripID.putExtra("key_ID",TripID); 

      TripID = ID; 

      Intent Openactivity = new Intent(HistoryListActivity.this, HistoryViewerActivity.class); 
      //Openactivity.putExtra("key_ID",id); 
      startActivity(Openactivity); 

     } 
    }); 
} 

protected void onPause() { 
    super.onPause(); 
    finish(); 
} 


} 

这里的Recieving活动：

TextView TripName, TripReason, cityName, SD, AD, budget, HE, TE, FE, EE, SE, OE, RemainBudget; 

ImageButton CheckedIn; 

long idDB = HistoryListActivity.TripID; 

String name ; 

String city; 
String reason; 
String startingdate; 
String arrivaldate; 
String tbudget; 

int hexp; 
int texp; 
int fexp; 
int eexp; 
int sexp; 
int oexp; 

int rbudget; 

TrackerDAO dbHelper; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_history_viewer); 

    TripName = (TextView) findViewById(R.id.textView_History_TripName); 

    cityName = (TextView) findViewById(R.id.textView_History_CityName); 
    TripReason = (TextView) findViewById(R.id.textView_History_TripReason); 
    SD = (TextView) findViewById(R.id.textView_History_SD); 
    AD = (TextView) findViewById(R.id.textView__History_AD); 
    budget = (TextView) findViewById(R.id.textView_History_Budget); 

    HE = (TextView) findViewById(R.id.textView_History_Hotel); 
    TE = (TextView) findViewById(R.id.textView_History_Transport); 
    FE = (TextView) findViewById(R.id.textView__History_Food); 
    EE = (TextView) findViewById(R.id.textView_History_Entertainment); 
    SE = (TextView) findViewById(R.id.textView_History_Shopping); 
    OE = (TextView) findViewById(R.id.textView_History_Other); 
    RemainBudget = (TextView) findViewById(R.id.textView_History_RemainingBudget); 

    CheckedIn = (ImageButton) findViewById(R.id.imageButton_CheckedIN); 

    displayshowHistory(idDB); 

    TripName.setText(name); 
    cityName.setText(city); 
    TripReason.setText(reason); 
    SD.setText(startingdate); 
    AD.setText(arrivaldate); 
    budget.setText(tbudget); 
    HE.setText(String.valueOf(hexp)); 
    TE.setText(String.valueOf(texp)); 
    FE.setText(String.valueOf(fexp)); 
    EE.setText(String.valueOf(eexp)); 
    SE.setText(String.valueOf(sexp)); 
    OE.setText(String.valueOf(oexp)); 
    RemainBudget.setText(String.valueOf(rbudget)); 

    CheckedIn.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 


     } 
    }); 

} 

private void displayshowHistory(long id) { 

     dbHelper.open(); 

     Cursor cursor = dbHelper.getInfo(id); 

     if (cursor.moveToFirst()) { 
      //idDB = cursor.getLong(TrackerDAO.COL_ROWID); 
      name = cursor.getString(TrackerDAO.COL_NAME); 
      city = cursor.getString(TrackerDAO.COL_CITY); 
      reason = cursor.getString(TrackerDAO.COL_REASON); 
      startingdate = cursor.getString(TrackerDAO.COL_SOD); 
      arrivaldate = cursor.getString(TrackerDAO.COL_AD); 
      tbudget = cursor.getString(TrackerDAO.COL_BUDGET); 

      hexp = cursor.getInt(TrackerDAO.COL_HE); 
      texp = cursor.getInt(TrackerDAO.COL_TE); 
      fexp = cursor.getInt(TrackerDAO.COL_FE); 
      eexp = cursor.getInt(TrackerDAO.COL_EE); 
      sexp = cursor.getInt(TrackerDAO.COL_SE); 
      oexp = cursor.getInt(TrackerDAO.COL_OE); 
      rbudget = cursor.getInt(TrackerDAO.COL_REMAINBUDGET); 

      /*historyString = "Trip Name: " + tripname + "\n" 
        + "City: " + city + "\n" 
        + "Reason For travel: " + tripreason + "\n" 
        + "Starting Date: " + sd + "\n" 
        + "Date of Arrival: " + ad + "\n" 
        + "Estimated Budget: " + tbudget + "\n" 
        + "Hotel Rents: " + he + "\n" 
        + "Tansport Fares: " + te + "\n" 
        + "Food Costs: " + fe + "\n" 
        + "Entertainment Spendings: " + ee + "\n" 
        + "Shopping Expenditure: " + se + "\n" 
        + "Other Expenses: " + oe + "\n" 
        + "Remain Money: " + rbudget; */ 
     } 

     dbHelper.close(); 

    } 
} 

现在这里是logcat的：

01-28 08:23:56.612: E/AndroidRuntime(1140): FATAL EXCEPTION: main 
01-28 08:23:56.612: E/AndroidRuntime(1140): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.blackcat.triporganizer/com.blackcat.triporganizer.history.HistoryViewerActivity}: java.lang.NullPointerException 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread.access$600(ActivityThread.java:141) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.os.Handler.dispatchMessage(Handler.java:99) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.os.Looper.loop(Looper.java:137) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread.main(ActivityThread.java:5103) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at java.lang.reflect.Method.invokeNative(Native Method) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at java.lang.reflect.Method.invoke(Method.java:525) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at dalvik.system.NativeStart.main(Native Method) 
01-28 08:23:56.612: E/AndroidRuntime(1140): Caused by: java.lang.NullPointerException 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at com.blackcat.triporganizer.history.HistoryViewerActivity.displayshowHistory(HistoryViewerActivity.java:92) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at com.blackcat.triporganizer.history.HistoryViewerActivity.onCreate(HistoryViewerActivity.java:63) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.Activity.performCreate(Activity.java:5133) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
01-28 08:23:56.612: E/AndroidRuntime(1140):  ... 11 more 

Answer 1

我认为你是displayshowHistory()方法中得到null pointer exception。该问题可能是该方法中未初始化的对象o请检查是否有任何未初始化的对象。通过你的第二个活动变化MainActivity2：

Answer 2

在我来说，我只是说第二个活动清单文件和每一件事成为确定：

补充一点：<activity android:name=".MainActivity2"></activity>

音符。

你的最后文件将是这样的：

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

    <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"> 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 
     <activity android:name=".MainActivity2"></activity> 
    </application> 

</manifest>