Я написал приложение, похожее на контакты в Android. У меня есть несколько элементов в моем списке, когда я нажимаю на них, я получаю информацию из базы данных и отображаю в другом представлении. Но когда я нажимаю на одно из имен в представлении списка, я получаю пустой экран (эмулятор выходит на экран) , Пожалуйста, помогите, я новичок в программировании Android. все предложения приветствуются

Благодарю вас

public class Contacts extends Activity implements OnClickListener {
    int NewContact_Request_Code = 1;
    Button newcontact;
    ListView listview;
    public static final String LOG_TAG = "Contacts";
    int mInt = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.contactview);
        // Set the content to contactview.xml

        // newcontact = NEW CONTACT button
        // listview = MyList List View
        newcontact = (Button) findViewById(R.id.baddcontact);
        listview = (ListView) findViewById(R.id.mylist);

        // Make a New Database
        DBContact info = new DBContact(this);
        // Open , get Information from database and close it
        info.open();
        String[] data = info.queryAll();
        info.close();
        // listview = getListView();
        listview.setTextFilterEnabled(true);
        // Display the names
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(Contacts.this,
                android.R.layout.simple_list_item_1, data);
        listview.setAdapter(adapter);
        listview.setOnItemClickListener(new OnItemClickListener() {

            public void onItemClick(AdapterView adapterView, View view,
                    int position, long id) {

                String nameclicked = adapterView.getItemAtPosition(position)
                        .toString();
                Intent viewintent = new Intent(Contacts.this, ViewContact.class);
                viewintent.putExtra("name_clicked", nameclicked);
                startActivity(viewintent);

            }
        });
        newcontact.setOnClickListener(this);

    }

    public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent newintent = new Intent(Contacts.this, AddNewContact.class);
        // start actiivity for result - to get the name of the new contact
        startActivityForResult(newintent, 0);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        // pass the value of the string via cursor and update the list
    }

}

ViewCOntact.class

public class ViewContact extends Activity implements OnClickListener {
    Button ViewPPhone, ViewHPhone, ViewOPhone, EditContact;
    TextView ViewName;
    TextView ViewPersonalPhone;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.viewcontact);
        Bundle extras = getIntent().getExtras();
       String name = extras.getString("name_clicked");
        Long l = Long.parseLong(name);
        DBContact getdetails = new DBContact(this);
        getdetails.open();
        String returnedname = getdetails.getName(l);
        String returnedpphone = getdetails.getPphone(l);
        String returnedhphone = getdetails.getHphone(l);
        String returnedophone = getdetails.getOphone(l);
        getdetails.close();
        ViewName.setText(returnedname);
        ViewPPhone.setText(returnedpphone);
        ViewHPhone.setText(returnedhphone);
        ViewOPhone.setText(returnedophone);

        EditContact = (Button) findViewById(R.id.bEditContact);
        EditContact.setOnClickListener(this);
        ViewPPhone = (Button) findViewById(R.id.ViewPersonalPhoneNumber);
        ViewPPhone.setOnClickListener(this);
        ViewHPhone = (Button) findViewById(R.id.ViewHomePhoneNumber);
        ViewHPhone.setOnClickListener(this);
        ViewOPhone = (Button) findViewById(R.id.ViewOfficePhoneNumber);
        ViewOPhone.setOnClickListener(this);

    }

    public void onClick(View view) {
        // TODO Auto-generated method stub
        switch (view.getId()) {
        case R.id.ViewPersonalPhoneNumber:
            Intent dialpersonalphone = new
            Intent(android.content.Intent.ACTION_DIAL,
            Uri.parse("returnedpphone"));
            startActivity(dialpersonalphone );
            break;

        case R.id.ViewHomePhoneNumber:
            Intent dialhome = new
            Intent(android.content.Intent.ACTION_DIAL,
            Uri.parse("returnedhphone"));
            startActivity(dialhome);
            break;

        case R.id.ViewOfficePhoneNumber:
            Intent dialoffice = new
            Intent(android.content.Intent.ACTION_DIAL,
            Uri.parse("returnedophone"));
            startActivity(dialoffice);
            break;

        case R.id.bEditContact:
            startActivity(new Intent("com.example.contactlist.EDITCONTACT"));
            break;
        }
    }

}

LogCat

09-26 02:52:11.527: W/dalvikvm(1605): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
09-26 02:52:11.558: E/AndroidRuntime(1605): FATAL EXCEPTION: main
09-26 02:52:11.558: E/AndroidRuntime(1605): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.contactlist/com.example.contactlist.ViewContact}: java.lang.NumberFormatException: Invalid long: ""
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.os.Looper.loop(Looper.java:137)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread.main(ActivityThread.java:4745)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at java.lang.reflect.Method.invokeNative(Native Method)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at java.lang.reflect.Method.invoke(Method.java:511)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at dalvik.system.NativeStart.main(Native Method)
09-26 02:52:11.558: E/AndroidRuntime(1605): Caused by: java.lang.NumberFormatException: Invalid long: ""
09-26 02:52:11.558: E/AndroidRuntime(1605):     at java.lang.Long.invalidLong(Long.java:125)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at java.lang.Long.parseLong(Long.java:346)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at java.lang.Long.parseLong(Long.java:319)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at com.example.contactlist.ViewContact.onCreate(ViewContact.java:24)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.Activity.performCreate(Activity.java:5008)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
09-26 02:52:11.558: E/AndroidRuntime(1605):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
09-26 02:52:11.558: E/AndroidRuntime(1605):     ... 11 more

БАЗА ДАННЫХ

public class DBContact {

    public static final String KEY_ROWID = "_id";
    public static final String KEY_NAME = "Name";
    public static final String KEY_PERSONALPHONE = "Personalnumber";
    public static final String KEY_HOMEPHONE = "Homenumber";
    public static final String KEY_OFFICEPHONE = "Officenumber";

    private static final String DATABASE_NAME = "Contacts";
    private static final String DATABASE_TABLE = "ContactList";
    private static final int DATABASE_VERSION = 1;

    // Instance of the class DbHelper
    private DbHelper ourHelper;
    private final Context ourContext;
    private SQLiteDatabase ourDatabase;

    public static final String[] KEYS_ALL = { DBContact.KEY_ROWID,
            DBContact.KEY_NAME, DBContact.KEY_PERSONALPHONE,
            DBContact.KEY_HOMEPHONE, DBContact.KEY_OFFICEPHONE };

    private static class DbHelper extends SQLiteOpenHelper {

        private static final String DATABASE_CREATE = "create table ContactList (_id integer primary key autoincrement, "
                + "Name text not null, Personalnumber text not null, Homenumber text not null, Officenumber text not null); ";

        public DbHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            // TODO Auto-generated constructor stub
        }

        @Override
        public void onCreate(SQLiteDatabase ourDatabase) {
            // TODO Auto-generated method stub
            try {
                ourDatabase.execSQL(DATABASE_CREATE);
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }           

        @Override
        public void onUpgrade(SQLiteDatabase ourDatabase, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub
            ourDatabase.execSQL("DROP TABLE IF EXISTS ContactList");
            onCreate(ourDatabase);

        }

    }

    // Context of constructor withhin our Class
    public DBContact(Context c) {
        ourContext = c;
    }

    // Opens the database
    public DBContact open() throws SQLException {
        // Constructor for DB Helper class takes in a Context
        // Context is passed in is "ourContext" for within our class

        ourHelper = new DbHelper(ourContext);
        // Passes in DB Name and Version
        // ourDatabase is of type SQLite DataBase
        ourDatabase = ourHelper.getWritableDatabase();
        return this;
    }

    // Closes the database connection
    public void close() {
        // refer to our DbHelper and close the SQLite DataBase Helper
        ourHelper.close();
        ourHelper = null;
        ourDatabase = null;
    }

    // Deletes the Row
    public boolean deleteRow(long rowId) {
        return ourDatabase.delete(DATABASE_TABLE, DBContact.KEY_ROWID + "="
                + rowId, null) > 0;
    }

    public String[] queryAll() {
        String[] columns = new String[] { KEY_NAME };
        Cursor cursor = ourDatabase.query(DATABASE_TABLE, columns, null, null,
                null, null, null);
        if (cursor != null) {
            try {
        final int nameColumnIndex = cursor.getColumnIndex(KEY_NAME);
        List<String> names = new ArrayList<String>();
        cursor.moveToFirst();
        while (cursor.moveToNext()) {
            names.add(cursor.getString(nameColumnIndex));
        }
        return names.toArray(new String[names.size()]);
    } finally {
        cursor.close();
   }
        }
        return null;
        //return columns;

    }

    /*public Cursor queryAll(){
    String[] columns = new String[] {KEY_NAME};
        return   ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
    if(data == null){
        columns[0] = "NO CONTACTS PRESENT";
        return columns;
    }else{
        return columns;
    }


    }*/


    public long newRow(String name, String pphone, String hphone, String ophone) {
        // TODO Auto-generated method stub
        ContentValues newvalue = new ContentValues();
        newvalue.put(KEY_NAME, name);
        newvalue.put(KEY_PERSONALPHONE, pphone);
        newvalue.put(KEY_HOMEPHONE, hphone);
        newvalue.put(KEY_OFFICEPHONE, ophone);
        return ourDatabase.insert(DATABASE_TABLE, null, newvalue);

    }



    public String getName(Long l) {
        // TODO Auto-generated method stub
        String[] columns = new String[] { KEY_ROWID, KEY_NAME,
                KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
        Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
                + 1, null, null, null, null);
        if (c != null) {
            c.moveToFirst();
            String name = c.getString(1);
            return name;
        }
        return null;
    }

    public String getPphone(Long l) {
        // TODO Auto-generated method stub
        String[] columns = new String[] { KEY_ROWID, KEY_NAME,
                KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
        Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
                + 1, null, null, null, null);
        if (c != null) {
            c.moveToFirst();
            String Pphone = c.getString(2);
            return Pphone;

        }
        return null;
    }

    public String getHphone(Long l) {
        // TODO Auto-generated method stub
        String[] columns = new String[] { KEY_ROWID, KEY_NAME,
                KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
        Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
                + 1, null, null, null, null);
        if (c != null) {
            c.moveToFirst();
            String Hphone = c.getString(3);
            return Hphone;

        }
        return null;
    }

    public String getOphone(Long l) {
        // TODO Auto-generated method stub
        String[] columns = new String[] { KEY_ROWID, KEY_NAME,
                KEY_PERSONALPHONE, KEY_HOMEPHONE, KEY_OFFICEPHONE };
        Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
                + 1, null, null, null, null);
        if (c != null) {
            c.moveToFirst();
            String Ophone = c.getString(4);
            return Ophone;

        }
        return null;
    }
}