该应用程序。在数据库中插入一行时发生崩溃

我只有一个SQLite表只用于测试某些东西，但我不知道应用程序崩溃的原因。该应用程序。在数据库中插入一行时发生崩溃

这里是SQLite的类：

public class DBDemoActivity extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION = 2; 
    private static final String DATABASE_NAME = "DBDemo.db"; 
    private static final String MP_TABLE_NAME = "Demo"; 

    DBDemoActivity (Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    }// end of 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     // TODO Auto-generated method stub 
     db.execSQL(" CREATE TABLE " + MP_TABLE_NAME + " (" + 
       BaseColumns._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
       " name TEXT, " + 
       " lat REAL, " + 
       " lng REAL " + 
       ");"); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // TODO Auto-generated method stub 
    } 

    public String getName(long id) { 
     SQLiteDatabase db = this.getReadableDatabase(); 
     SQLiteCursor c = (SQLiteCursor) db.rawQuery("SELECT name FROM Demo WHERE "+ 
                BaseColumns._ID+" = "+ 
                Long.toString(id), null); 
     countRows(c); 
     c.moveToFirst(); 
     String r = c.getString(0); 
     c.close(); 
     db.close(); 
     return r;  
    } 

    public int countRows(SQLiteCursor c) { 
     return c.getCount(); 
    } 
}

和这里的活动：

public class DemoData extends Activity{ 

    DBDemoActivity dbd; 
    SQLiteDatabase db; 
    ContentValues cv; 

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

     dbd = new DBDemoActivity(this); 
     db = dbd.getWritableDatabase(); 
     cv = new ContentValues(); 

     cv.put("name", "Amr"); 
     cv.put("lat", 10); 
     cv.put("lng", 20); 

     long newID = db.insert("Demo", null, cv); 

     if (newID != -1){ 
      Toast.makeText(getBaseContext(), 
          "data saved ", 
          Toast.LENGTH_SHORT).show();   
     }// end if*/   
    } 
}

这里是logcat的：

02-26 20:28:55.530: E/AndroidRuntime(17124): FATAL EXCEPTION: main 
02-26 20:28:55.530: E/AndroidRuntime(17124): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.androidbook.DBDemo/com.androidbook.DBDemo.DBDemoActivity}: java.lang.InstantiationException: com.androidbook.DBDemo.DBDemoActivity 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1573) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.os.Handler.dispatchMessage(Handler.java:99) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.os.Looper.loop(Looper.java:123) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.main(ActivityThread.java:3691) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.reflect.Method.invokeNative(Native Method) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.reflect.Method.invoke(Method.java:507) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at dalvik.system.NativeStart.main(Native Method) 
02-26 20:28:55.530: E/AndroidRuntime(17124): Caused by: java.lang.InstantiationException: com.androidbook.DBDemo.DBDemoActivity 
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.Class.newInstanceImpl(Native Method) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.Class.newInstance(Class.java:1409) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1565) 
02-26 20:28:55.530: E/AndroidRuntime(17124): ... 11 more

来源

2012-02-26 LetsamrIt

重组你的logcat，并检查您在manifiest文件中添加你的活动 – 2012-02-26 19:40:37

我已经加入这两项活动清单 – LetsamrIt 2012-02-26 19:51:21

@ user1121443：如果您的意思是您的清单中有'DBDemoActivity'条目，那么您不应该有。它是一个'SQLiteOpenHelper'而不是'Activity'，所以不应该被命名为一个，并且在清单文件中不应该有任何地方的任何条目。 – Squonk 2012-02-26 19:56:08

清单文件应包含定义每活动内的应用程序。
因此您的清单应该包含如下：

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

和不应包含

<activity 
     android:name=".DBDemoActivity"> 
    </activity>

来源

2012-04-24 10:27:13 GAMA

该应用程序。在数据库中插入一行时发生崩溃

回答

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