Java – how to create a new activity, I can choose to add a new project from the database?

I created the database after this tutorial, and I created a button in the main activity that takes the user to another activity where they will add some new projects But I don't know how to use ArrayList to do this because I want to add a new item to the listview I want something like this in my application Any help will be belittled

This is the code of the database:

public class DatabaseHandler extends sqliteOpenHelper {

    // All Static variables
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "itemManager";

    // Contacts table name
    private static final String TABLE_ITEMS = "items";

    // Contacts Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_TITLE = "title";
    private static final String KEY_PRICE = "price";

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

    // Creating Tables
    @Override
    public void onCreate(sqliteDatabase db) {
        String CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + "("
                + KEY_ID + " INTEGER PRIMARY KEY," + KEY_TITLE + " TEXT,"
                + KEY_PRICE + " TEXT" + ")";
        db.execsql(CREATE_ITEMS_TABLE);
    }

    // Upgrading database
    @Override
    public void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) {
        // Drop older table if existed
        db.execsql("DROP TABLE IF EXISTS " + TABLE_ITEMS);

        // Create tables again
        onCreate(db);
    }
    /**
     * All CRUD(Create,Read,Update,Delete) Operations
     */

    // Adding new item
    void addItem(Item item) {
        sqliteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_TITLE,item.getTitle()); // Title Name
        values.put(KEY_PRICE,item.getPrice()); // Price

        // Inserting Row
        db.insert(TABLE_ITEMS,values);
        db.close(); // Closing database connection
    }

    // Getting item
    Item getItem(int id) {
        sqliteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_ITEMS,new String[] { KEY_ID,KEY_TITLE,KEY_PRICE },KEY_ID + "=?",new String[] { String.valueOf(id) },null);
        if (cursor != null)
            cursor.moveToFirst();

        Item item = new Item(Integer.parseInt(cursor.getString(0)),cursor.getString(1),cursor.getString(2));
        // return item
        return item;
    }

    // Getting All Items
    public List<Item> getAllItems() {
        List<Item> itemsList = new ArrayList<Item>();
        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_ITEMS;

        sqliteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery,null);

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Item item = new Item();
                item.setID(Integer.parseInt(cursor.getString(0)));
                item.setTitle(cursor.getString(1));
                item.setPrice(cursor.getString(2));
                // Adding contact to list
                itemsList.add(item);
            } while (cursor.moveToNext());
        }

        // return items list
        return itemsList;
    }

    // Updating single item
    public int updateItem(Item item) {
        sqliteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_TITLE,item.getTitle());
        values.put(KEY_PRICE,item.getPrice());

        // updating row
        return db.update(TABLE_ITEMS,values,KEY_ID + " = ?",new String[] { String.valueOf(item.getID()) });
    }

    // Deleting single item
    public void deleteItem(Item item) {
        sqliteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_ITEMS,new String[] { String.valueOf(item.getID()) });
        db.close();
    }

    // Getting items Count
    public int getItemsCount() {
        String countQuery = "SELECT  * FROM " + TABLE_ITEMS;
        sqliteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery,null);
        cursor.close();

        // return count
        return cursor.getCount();
    }

}

This is the code for mainactivity:

public class MainActivity extends BaseActivity {

    Button addItem;
    private Toolbar toolbar;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        FrameLayout frameLayout = (FrameLayout)findViewById(R.id.frame_container);

         // inflate the custom activity layout
        LayoutInflater layoutInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View activityView = layoutInflater.inflate(R.layout.activity_main,false);

        frameLayout.addView(activityView);

        // Setting toolbar
        toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        DatabaseHandler db = new DatabaseHandler(this);

        addItem = (Button) findViewById(R.id.button1);
        addItem.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,AddActivity.class);
                startActivity(intent);

            }
        });
    }
}

This is my main activity layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mainContent"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <include
        android:id="@+id/app_bar"
        layout="@layout/app_bar" />

    <Button
        android:id="@+id/button1"
        style="@style/MyCustomButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:text="@string/button" />

    <ListView
        android:id="@+id/list"
        android:layout_margin="5dp"
        android:layout_below="@+id/relativeLayout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/button1"
        android:layout_centerHorizontal="true"
        android:divider="@color/list_divider_row"
        android:dividerHeight="10.0sp"
        android:listSelector="@drawable/list_row_selector" >
    </ListView>

    <RelativeLayout
        android:id="@+id/relativeLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/listView1"
        android:layout_alignRight="@+id/listView1"
        android:layout_below="@+id/app_bar"
        android:padding="10dp" >

        <TextView
            android:id="@+id/item_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="4dp"
            android:text="Items"
            android:textColor="#474747"
            android:textSize="16sp" />

        <TextView
            android:id="@+id/item_count"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_marginLeft="5dp"
            android:layout_marginTop="4dp"
            android:layout_toRightOf="@+id/item_text"
            android:text="(2)"
            android:textColor="#474747"
            android:textSize="14sp" />

        <TextView
            android:id="@+id/total_amount"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:text="Rs. 5700"
            android:textColor="#000000"
            android:textSize="20dp" />

    </RelativeLayout>

</RelativeLayout>

Solution

In short, you need to pass the "results" of adding the project back to the main activity Then, if an item is added, the adapter should be called to update the adapter data

// Your prevIoUs code       
addItem = (Button) findViewById(R.id.button1);
        addItem.setOnClickListener(new View.OnClickListener() {

            @Override 
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,AddActivity.class);
                startActivityForResult(intent,ADD_ITEM_REQ_CODE);

            } 
        }); 

// Then handle the result
public void onActivityResult(int reqCode,int resultCode,Intent data){
  if (reqCode == ADD_ITEM_REQ_CODE && resultCode == RESULT_OK){
    // get your ListView adapter and update data
    mlistadapter.notifyDataSetChanged();
  }
}

For the second activity, the activity adding the project should call setresult (result_ok) when the project is successfully added, otherwise call setresult (result_canceled)

Your code also has other functions, such as where do you populate the listview? Usually, you can get the instance through findviewbyid and set the adapter for the listview with the corresponding data

To be honest, I think you should look at these tutorials again, especially these: http://developer.android.com/training/basics/intents/result.html http://developer.android.com/guide/topics/ui/layout/listview.html