Android 无法将文本从编辑 TextView 保存到数据库

Question

在我的应用程序中，我允许用户向某些号码发送警报消息。用户可以在 EditText 中编写自己选择的任何文本，也可以从 spinner 的预定义文本中选择文本。早些时候我将文本保存到 SharedPreferences 但现在我希望它在 SQLite 中。我能够将联系电话保存到用户想要发送的数据库中消息，但我无法将消息保存到数据库。我希望当用户输入自己的文本或从 spinner 中选择任何文本后，他按下保存按钮并将文本保存到数据库中。请帮助。P.S _ 我认为在从数据库调用方法到按钮 onclick 时遇到了问题。请查看我的代码并建议我该怎么做。

主 Activity .java

public class MainActivity extends Activity implements LocationListener {
    String separator = "; ";
    private Button btn_cntct;
    private EditText message;
    LinearLayout linearLayoutSec;
    private Button GPSState;
    Button b_alert;
    Button b_save_message;
    public int REQUESTCODE = 1;
    int temp;
    ScrollView ScrView;
    Context c = MainActivity.this;
    Button AlertMessages;
    private static ArrayList<ContactItems> selectedContactList = new ArrayList<ContactItems>();
    static CustomAdapter adapter;
    public static String[] myvalue = new String[1];
    Spinner spinner;
    static String[] alert = { " ", "I am in danger", "Help Me", "Watch Out",
            "Look For Me", "Cover ME" };
    MySQLiteHelper dbHelper;
    String savedMessage;
    Button save;

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    message = (EditText) findViewById(R.id.et_message);
    // message.setFocusable(false);
    dbHelper = new MySQLiteHelper(this);
    String dis = dbHelper.getMsg();
    if (dis != null) {
        message.setText(dis);
    }

    bsave = (Button) findViewById(R.id.b_save);
    bsave.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String str = message.getText().toString();
            dbHelper.updateMsg(str);

        }
    });




    spinner = (Spinner) findViewById(R.id.Spin_alert_message);

    ArrayAdapter<String> adp = new ArrayAdapter<String>(
            getApplicationContext(), android.R.layout.simple_spinner_item,
            alert);
    spinner.setAdapter(adp);

    spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int position, long id) {

            String selectedItem = alert[position];
            message.setText(selectedItem);

            // loads the text that has been stored to SP and set it to
            // EditText
            //message.setText(pref.getString("AutoSave", ""));
            // to bring cursor to front
            message.setSelection(message.getText().length());



        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
        }
    });

    /************************** saving custom message *****************************/

    // for saving text that user can change as per need

    ListView contactlist = (ListView) findViewById(R.id.contactListitems);
    Resources res = getResources();
    adapter = new CustomAdapter(MainActivity.this, selectedContactList, res,MainActivity.this);
    contactlist.setAdapter(adapter);

        /********************************* GPS *******************************/

        // checking if GPS is already on or not.
        // If not then displaying the alert dialog
        // requesting user to On GPS.
        GPSState = (Button) findViewById(R.id.bGPSstate);
        boolean isGPSEnabled = false; //
        // Declaring a Location Manager
        LocationManager locationManager;

        locationManager = (LocationManager) getApplicationContext()
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        if (!isGPSEnabled) {
            // no GPS provider is enabled
            // displaying GPS status on the button and and opening GPS settings

            GPSState.setText("GPS is off.turn it on");
            GPSState.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    startActivityForResult(
                            new Intent(
                                    android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS),
                            REQUESTCODE);

                }
            });
            // setting up the dialog box for GPS Settings

            // creating alertdialog
            AlertDialog.Builder builder = new AlertDialog.Builder(c);

            builder.setTitle("Settings");
            builder.setMessage("Enable GPS for the Application");

            builder.setPositiveButton("GPS Setting",

            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    startActivity(new Intent(
                            android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));

                    dialog.dismiss();

                }

            });

            builder.setNegativeButton("Cancel",
                    new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog, int which) {

                            new AlertDialog.Builder(MainActivity.this)
                                    .setTitle("How to use Application")
                                    .setMessage(
                                            "You must enable the GPS in order to use this application. Press Activate and then press Power Button twice in order to send the alert message to the selected contacts")
                                    .setNeutralButton(
                                            "OK",
                                            new DialogInterface.OnClickListener() {

                                                @Override
                                                public void onClick(
                                                        DialogInterface dialog,
                                                        int which) {
                                                    // do something // for //
                                                    // returning back to // //
                                                    // application
                                                    dialog.cancel();

                                                }
                                            }).show();
                            dialog.dismiss();

                        }
                    });

            builder.show();

        } else {
            GPSState.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    startActivityForResult(
                            new Intent(
                                    android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS),
                            REQUESTCODE);
                }
            });
        }

        // defining button elements for picking contacts from phone-book
        btn_cntct = (Button) findViewById(R.id.bpickperson);
        btn_cntct.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if (selectedContactList.size() < 4) {
                    // TODO Auto-generated method stub
                    // using Intent for fetching contacts from phone-book
                    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                    intent.setType(ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE);
                    startActivityForResult(intent, REQUESTCODE);
                } else {
                    // print toast for not allowing user to add more contacts
                    Toast.makeText(getApplicationContext(),
                            "You Can Only Add 4 Contacts ", Toast.LENGTH_SHORT)
                            .show();
                }

            }

        });

    }

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

    // calling onActivityResult when contacts has been selected from the
    // phone-book, giving back the REQUESTCODE i started it with, the RC it
    // returned with
    // any additional data from it.
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        boolean isGPSEnabled = false;
        GPSState = (Button) findViewById(R.id.bGPSstate);
        LocationManager locationManager;
        locationManager = (LocationManager) getApplicationContext()
                .getSystemService(LOCATION_SERVICE);
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
        if (!isGPSEnabled)
            GPSState.setText("GPS is off.Turn it on");
        else
            GPSState.setText("GPS is on");

        if (data != null) {
            Uri uri = data.getData();
            Log.i("data", uri.toString());
            if (uri != null) {
                Cursor c = null;
                try {
                    c = getContentResolver()
                            .query(uri,
                                    new String[] {
                                            ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
                                            ContactsContract.CommonDataKinds.Phone.NUMBER,
                                            ContactsContract.CommonDataKinds.Phone.TYPE },
                                    null, null, null);

                    if (c != null && c.moveToFirst()) {
                        final ContactItems item = new ContactItems(
                                c.getString(0), c.getString(1), c.getInt(2));
                        item.setName(c.getString(0));
                        item.setNumber(c.getString(1));
                        item.setType(c.getInt(2));
                        selectedContactList.add(item);

                        Set<ContactItems> s = new TreeSet<ContactItems>(
                                new Comparator<ContactItems>() {

                                    @Override
                                    public int compare(ContactItems o1,
                                            ContactItems o2) {
                                        // for preventing duplicacy of contacts
                                        // and calling toast
                                        if (o1.number.equals(o2.number)) {

                                            Toast.makeText(
                                                    getApplicationContext(),
                                                    "Selected Number Already Exists",
                                                    Toast.LENGTH_SHORT).show();
                                        } else {


                                        }
                                        return o1.getNumber().compareTo(
                                                o2.getNumber());

                                    }
                                });

                        s.addAll(selectedContactList);
                        selectedContactList.clear();
                        selectedContactList.addAll(s);
                        adapter.notifyDataSetChanged();
                        // save the task list to preference

                        dbHelper.insertContact(item);
                    }
                } finally {
                    if (c != null) {
                        c.close();
                    }
                }
            }
        }

    }

    @Override
    public void onLocationChanged(Location arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderDisabled(String arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
        // TODO Auto-generated method stub

    }

    /*
     * @Override public void onSaveInstanceState(Bundle outState) {
     * super.onSaveInstanceState(outState); // You put the content of your list,
     * which is this.mCachedData, in the // state
     * outState.putParcelableArrayList("ABC", selectedContactList); }
     */
    @Override
    public void onResume() {
        super.onResume();
        boolean isGPSEnabled = false;
        GPSState = (Button) findViewById(R.id.bGPSstate);
        LocationManager locationManager;
        locationManager = (LocationManager) getApplicationContext()
                .getSystemService(LOCATION_SERVICE);
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
        if (!isGPSEnabled)
            GPSState.setText("GPS is off.Turn it on");
        else
            GPSState.setText("GPS is on");
    }

}// final parentheses

MySQLiteHelper.java

public class MySQLiteHelper extends SQLiteOpenHelper {

      public static final String TABLE_NAME = "userdetails";
      public static final String TABLE_NAME_MSG = "usermessage";
      public static final String COLUMN_ID = "_id";
      public static final String COLUMN_NUMBER = "NUMBER";
      public static final String COLUMN_NAME = "name";
      public static final String COLUMN_TYPE = "type";
      public static final String COLUMN_ID_MSG = "_id";
      public static final String COLUMN_MSG = "message";
      private static final String DATABASE_NAME = "userInformation.db";

      private static final int DATABASE_VERSION = 1;
      private static final String LOG = "DatabaseHelper";

      // Database creation sql statement
      private static final String DATABASE_CREATE_TABLE_CONTACTS = "create table "
          + TABLE_NAME + "(" + COLUMN_ID
          + " integer primary key autoincrement, " + COLUMN_NAME
          + " text not null,"+COLUMN_NUMBER+"  text not null,"+COLUMN_TYPE+" text not null);";
      private static final String DATABASE_CREATE_TABLE_MSG = "create table "
              + TABLE_NAME_MSG + "(" + COLUMN_ID_MSG
              + " integer primary key autoincrement, " + COLUMN_MSG    + " text not null);";
      private static final String DATABASE_INSERT_MSG = "insert into  "
              + TABLE_NAME_MSG + "(" + COLUMN_MSG+") VALUES('enter your message');";


      public MySQLiteHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
      }

      @Override
      public void onCreate(SQLiteDatabase database) {
        database.execSQL(DATABASE_CREATE_TABLE_CONTACTS);
        database.execSQL(DATABASE_CREATE_TABLE_MSG);
        database.execSQL(DATABASE_INSERT_MSG);

      }

      @Override
      public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(MySQLiteHelper.class.getName(),
            "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
      }

      public long insertContact(ContactItems contItem) {
            SQLiteDatabase db = this.getWritableDatabase();

            ContentValues values = new ContentValues();
            values.put(COLUMN_NAME, contItem.getName());
            values.put(COLUMN_NUMBER, contItem.getNumber());
            values.put(COLUMN_TYPE, contItem.getType());

            // insert row
            long result = db.insert(TABLE_NAME, null, values);

            // assigning tags to todo
            /*for (long tag_id : tag_ids) {
                createTodoTag(todo_id, tag_id);
            }*/

            return result;
        }


      public ArrayList<ContactItems> getAllContacts() {
          ArrayList<ContactItems> contactList = new ArrayList<ContactItems>();
            String selectQuery = "SELECT  * FROM " + TABLE_NAME;

            Log.e(LOG, selectQuery);

            SQLiteDatabase db = this.getReadableDatabase();
            Cursor c = db.rawQuery(selectQuery, null);

            // looping through all rows and adding to list
            if (c.moveToFirst()) {
                do {
                    ContactItems conItems = new ContactItems();
                    conItems.setName(c.getString((c.getColumnIndex(COLUMN_NAME))));
                    conItems.setNumber((c.getString(c.getColumnIndex(COLUMN_NUMBER))));
                    conItems.setType(Integer.parseInt(c.getString(c.getColumnIndex(COLUMN_TYPE))));

                    // adding to todo list
                    contactList.add(conItems);
                } while (c.moveToNext());
            }

            return contactList;
        }

    public void updateMsg(String msg) {
        // TODO Auto-generated method stub
        // String selectQuery = "update  " + TABLE_NAME_MSG+" set "+COLUMN_MSG+" = '"+msg+"' where "+COLUMN_ID_MSG+" = 1";
          ContentValues values = new ContentValues();
            values.put(COLUMN_MSG, msg);
          SQLiteDatabase db = this.getReadableDatabase();
         db.update(TABLE_NAME_MSG, values, null, null);

    }
    public String getMsg() {
        String message ="";
          String selectQuery = "SELECT  * FROM " + TABLE_NAME_MSG;

          SQLiteDatabase db = this.getReadableDatabase();
            Cursor c = db.rawQuery(selectQuery, null);
            if (c.moveToFirst()) {
                do {
                    message = c.getString(c.getColumnIndex(COLUMN_MSG));
                } while (c.moveToNext());
            }

        // TODO Auto-generated method stub
            Log.e(LOG, "message = "+message);
        return message;

    }

    public int removeData(String number) {
        // TODO Auto-generated method stub

          SQLiteDatabase db = this.getReadableDatabase();
           //db.drawQuery(deleteQuery, null);
          return db.delete(TABLE_NAME, COLUMN_NUMBER + "='" + number+"'", null) ;

    }

    } 

自定义适配器.java

public class CustomAdapter extends BaseAdapter {

    /*********** Declare Used Variables *********/
    private Activity activity;
    private ArrayList<ContactItems> data;
    private static LayoutInflater inflater = null;
    public Resources res;

    MySQLiteHelper dbHelper;
    // ListModel tempValues=null;
    int i = 0;
    String selectedNum = " ";
    Context contxt;

    /************* CustomAdapter Constructor *****************/
    public CustomAdapter(Activity a, ArrayList<ContactItems> d,
            Resources resLocal,Context context) {

        /********** Take passed values **********/
        activity = a;
        data = d;
        res = resLocal;
        contxt= context;
        dbHelper= new MySQLiteHelper(contxt);

        /*********** Layout inflator to call external xml layout () ***********/
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }

    /******** What is the size of Passed Arraylist Size ************/
    public int getCount() {

        if (data.size() <= 0)
            return 1;
        return data.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    /********* Create a holder Class to contain inflated xml file elements *********/
    public static class ViewHolder {

        public TextView text;
        public TextView textNumber;

        public ImageView image;

    }

    /****** Depends upon data size called for each row , Create each ListView row *****/
    @SuppressLint("DefaultLocale")
    public View getView(int position, View convertView, ViewGroup parent) {
        final int pos = position;
        View vi = convertView;
        ViewHolder holder;
        // check if converView is null, if it is null it probably means
        if (convertView == null) {

            /****** Inflate tabitem.xml file for each row ( Defined below ) *******/
            vi = inflater.inflate(R.layout.contactlistitem, null);

            /****** View Holder Object to contain tabitem.xml file elements ******/
            // if it is not null, just reuse it from the recycler
            holder = new ViewHolder();
            holder.text = (TextView) vi.findViewById(R.id.contactname);
            holder.textNumber = (TextView) vi.findViewById(R.id.contactnumber);
            holder.image = (ImageView) vi.findViewById(R.id.deleteimage);

            /************ Set holder with LayoutInflater ************/
            vi.setTag(holder);
        } else
            holder = (ViewHolder) vi.getTag();

        if (data.size() <= 0) {

            holder.text.setText("Add");
            holder.textNumber.setText(" ");
            holder.image.setVisibility(View.GONE);

        } else {
            /***** Get each Model object from Arraylist ********/

            /************ Set Model values in Holder elements ***********/

            holder.text.setText("" + data.get(position).getName());

            holder.textNumber.setText("" + data.get(position).getNumber());
            holder.image.setVisibility(View.VISIBLE);
            holder.image.setImageResource(res.getIdentifier("delete_button",
                    null, null));

            holder.image.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    AlertDialog.Builder build = new AlertDialog.Builder(
                            activity);
                    build.setTitle("Delete");
                    build.setMessage("Are You Sure");
                    build.setPositiveButton("Delete",
                            new DialogInterface.OnClickListener() {

                                @Override
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // TODO Auto-generated method stub

                                    dbHelper.removeData(data.get(pos).getNumber());
                                    data.remove(pos);
                                    MainActivity.adapter.notifyDataSetChanged();
                                    dialog.dismiss();
                                }
                            });

                    /*
                     * data.remove(pos);
                     * MainActivity.adapter.notifyDataSetChanged();
                     */
                    build.setNegativeButton("Cancel",
                            new DialogInterface.OnClickListener() {

                                @Override
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // TODO Auto-generated method stub
                                    dialog.dismiss();
                                }
                            });
                    build.show();
                }

            });
            /******** Set Item Click Listner for LayoutInflater for each row *******/

        }
        // return the view for a single item in the listview
        return vi;
    }

}

ContactItems.java

public class ContactItems implements Parcelable {
    String name = "";
    String number = "";
    int type = 0;

    public ContactItems(String name, String number, int type) {
        super();
        this.name = name;
        this.number = number;
        this.type = type;
    }

    public ContactItems(Parcel source) {
        // TODO Auto-generated constructor stub

        this.name = source.readString();
        this.number = source.readString();
        this.type = source.readInt();
    }
    public ContactItems() {
        // TODO Auto-generated constructor stub

        super();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getNumber() {
        return number;
    }

    public void setNumber(String number) {
        this.number = number;
    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }

    @Override
    public int describeContents() {
        // TODO Auto-generated method stub
        return 0;
    }

    public static final Parcelable.Creator<ContactItems> CREATOR = new Parcelable.Creator<ContactItems>() {

        @Override
        public ContactItems createFromParcel(Parcel source) {
            return new ContactItems(source);
        }

        @Override
        public ContactItems[] newArray(int size) {
            return new ContactItems[size];
        }

    };

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        // TODO Auto-generated method stub
        dest.writeString(name);
        dest.writeString(number);
        dest.writeInt(type);

    }

Answer 1

只需在单击按钮时调用将消息插入或更新到数据库中的方法，在调用该方法之前，只需将 EditText 的值获取到某个变量中，并将该变量作为参数传递到数据库中.

尝试如下:

 save.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View arg0) {

            String str = message.getText().toString(); 
             dbHelper.updateMsg(str);
        }
    });

已编辑:

public boolean updateMsg(String msg) {

          ContentValues values = new ContentValues();
            values.put(COLUMN_MSG, msg);
          SQLiteDatabase db = this.getReadableDatabase();
       return  db.update(TABLE_NAME_MSG, values, COLUMN_ID_MSG +"=1"+, null)>0;

    }