Question

I have made an app in which i am using Two Tabs,

First Tab, to show list of Products [Menu Tab]

Second Tab, to show products added by you [Cart Tab]

Here i am allowing user to add products to cart, update quantity for product and show total amount of all the Items.

In my code i am facing very small problem but i am not getting any way for last two days to resolve this.

Problem:

Whenever i do click on Cart Tab to view products, those i have selected to buy and then again move back to Menu Tab to select few more products to buy and then again do click on Cart Tab to view all products i have selected, Here i am able to view Selected Product but not able to view updated quantity and not getting any change in Total Amount [Getting total of all previous added items only, not for those i have added second time…]

Please tell me where i am missing, to get updated quantity and to get change in total price, what code i need to add and where i need to add in my ViewCartActivity class

ViewCartActivity.Java:

    public class ViewCartActivity extends Activity {

    TextView mTxtViewGrandTotal;
    String mGrandTotal ;


    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.viewcartactivity);

        ListView mLstView1 = (ListView) findViewById(R.id.listView1);
        mTxtViewGrandTotal = (TextView) findViewById(R.id.mTxtViewGrandTotalValue);

        ViewCartAdapter mViewCartAdpt = new ViewCartAdapter(ViewCartActivity.this);
        mLstView1.setAdapter(mViewCartAdpt);

        if (Constants.mItem_Detail.size() > 0) 
        {
            Double mGTotal = Double.parseDouble(Constants.mItem_Detail.get(0).get(SingleProductActivity.KEY_TOTAL));
            for (int i = 1; i < Constants.mItem_Detail.size(); i++) {   
                mGTotal = mGTotal + Double.parseDouble(Constants.mItem_Detail.get(i).get(SingleProductActivity.KEY_TOTAL));
            }

            mGrandTotal = String.valueOf(mGTotal);
            mTxtViewGrandTotal.setText(mGrandTotal);



            ImageButton mImgViewCart = (ImageButton) findViewById(R.id.back_btn);
            mImgViewCart.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {
                    // TODO Auto-generated method stub

                        Intent mViewCartIntent = new Intent(ViewCartActivity.this, com.version.bajrang.january.menu.ArrowsActivity.class);
                        startActivity(mViewCartIntent);


                }
            });     
        }
    }   

    @Override
    protected void onResume() {
    // TODO Auto-generated method stub
    System.out.println("onResume list current size "+Constants.mItem_Detail.size());
    super.onResume();
    }
}

In Logcat, i am getting:

onResume list current size 3 [Number of Records]

TabActivity.Java:

    private void setTabs()
{
    addTab("Order", R.drawable.tab_order, CategoryActivity.class);
    addTab("Cart", R.drawable.tab_cart, ViewCartActivity.class);
}

@Override
    public void onBackPressed() {
    // Code to update product Quantity
    super.onBackPressed();
    Constants.mItem_Detail.clear();
}

ViewCartAdapter.Java:

 public class ViewCartAdapter extends BaseAdapter {

Activity activity;
LayoutInflater inflater;

public ViewCartAdapter(Activity a) {
    // TODO Auto-generated constructor stub
    activity = a;
    inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
    // TODO Auto-generated method stub
    return Constants.mItem_Detail.size();
}
public Object getItem(int position) {
    //return position;
    return Constants.mItem_Detail.get(position);
}
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;

}
public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View vi = convertView;
    if (convertView == null)
        vi = inflater.inflate(R.layout.viewcartlist, null);
    TextView title = (TextView) vi.findViewById(R.id.title);
    TextView qty = (TextView) vi.findViewById(R.id.qty);
    TextView cost = (TextView) vi.findViewById(R.id.cost);

    HashMap<String, String> item = new HashMap<String, String>();
    item = Constants.mItem_Detail.get(position);
    // Setting all values in listview
    title.setText(item.get(SingleProductActivity.TAG_NAME));
    qty.setText(item.get(SingleProductActivity.KEY_QTY));
    cost.setText(item.get(SingleProductActivity.TAG_DURATION));
    return vi;
}   
   }

Answer 1

Rakesh you have written everything needed in your program, just need to move from onCreate() to onResume() Method in ViewCartActivity

Like this:

 public class ViewCartActivity extends Activity 
 {

TextView mTxtViewGrandTotal;
String mGrandTotal ;


@Override
protected void onCreate(Bundle savedInstanceState) 
{
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.viewcartactivity);

    ListView mLstView1 = (ListView) findViewById(R.id.listView1);
    mTxtViewGrandTotal = (TextView) findViewById(R.id.mTxtViewGrandTotalValue);

    ViewCartAdapter mViewCartAdpt = new ViewCartAdapter(ViewCartActivity.this);
    mLstView1.setAdapter(mViewCartAdpt);

        ImageButton mImgViewCart = (ImageButton) findViewById(R.id.back_btn);
        mImgViewCart.setOnClickListener(new OnClickListener() 
        {

            public void onClick(View v) {
                // TODO Auto-generated method stub

                    Intent mViewCartIntent = new Intent(ViewCartActivity.this, com.version.bajrang.january.menu.ArrowsActivity.class);
                    startActivity(mViewCartIntent);

            }
        });     
    }


@Override
protected void onResume() 
{
    super.onResume();
    System.out.println("onResume list current size " + Constants.mItem_Detail.size());

    if (Constants.mItem_Detail.size() == 0) 
    {
    return;
    }

    Double mGTotal = Double.parseDouble(Constants.mItem_Detail.get(0).get(SingleProductActivity.KEY_TOTAL));
    for (int i = 1; i < Constants.mItem_Detail.size(); i++) 
    {   
        mGTotal = mGTotal + Double.parseDouble(Constants.mItem_Detail.get(i).get(SingleProductActivity.KEY_TOTAL));
    }
    mGrandTotal = String.valueOf(mGTotal);
    mTxtViewGrandTotal.setText(mGrandTotal);
     }
   }