Question

我正在使用自定义适配器类，并希望向其添加TextView并在简单的Activity

中显示

User_cart.java  it is my activity

public class User_Cart extends FragmentActivity 
{
    CartAdapter adapter;
    ListView listview;
    ArrayList<HashMap<String, String>> arraylist;
    public static String DISH_NAME;
    public static String DISH_COST;
    public static String DISH_QUANTITY;
    Button order_btn;
    TextView result;
    Double quantitySTRtemp, costSTRtemp, totalSTR, subtotalSTR;
    private CoordinatorLayout coordinatorLayout;
    DatabaseHandler db = new DatabaseHandler(this);


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.user_cart);
        result = (TextView) findViewById(R.id.subtotalET);

        order_btn = (Button) findViewById(R.id.orderBT);

        arraylist = new ArrayList<HashMap<String, String>>();

        List<Order> orders = db.getAllOrders();

        Log.d("tot", "" + db.getOrdersCount());
//db.deleteall();
        for (Order cn : orders) {

            String log = "Id: " + cn.getID() + " ,Name: " + cn.getName() + " ,Cost: " + cn.getCost() + " Quantoty: " + cn.getQuantity();
            // Writing Contacts to log
           /* DISH_NAME = cn.getName();
            DISH_COST = cn.getCost();
            DISH_QUANTITY = cn.getQuantity();*/

            Log.d("Name: ", log);
            HashMap<String, String> map = new HashMap<String, String>();
            map.put("name", cn.getName());
            map.put("cost", cn.getCost());
            map.put("quantity", cn.getQuantity());
            arraylist.add(map);
            //  listview.getSelectedItem();

        }
        listview = (ListView) findViewById(R.id.userlistview);
        // Pass the results into ListViewAdapter.java
        adapter = new CartAdapter(User_Cart.this, arraylist);
        // Set the adapter to the ListView
        listview.setAdapter(adapter);
        Toolbar toolbar = (Toolbar) findViewById(R.id.menus_toolbar);
        toolbar.setNavigationIcon(R.mipmap.backbutton);
        calculateSum();
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onBackPressed();
            }
        });

        order_btn.setOnClickListener(new View.OnClickListener() {
            boolean showText = false;

            @Override
            public void onClick(View v) {

                Toast.makeText(User_Cart.this, "Thank You For order", Toast.LENGTH_LONG).show();
                db.deleteall();
                Intent intent = new Intent(User_Cart.this, MainActivity.class);


                startActivity(intent);

            }
        });
    }
    @Override
    public void onBackPressed() {

        //FragmentManager fm = User_Cart.this.getSupportFragmentManager();
        // fm.popBackStack();
        //getFragmentManager().popBackStackImmediate();
        super.onBackPressed();
    }

    public void calculateSum() {
        double sum = 0;
        List<Order> orders = db.getAllOrders();
        for (Order cn : orders) {


            try {
                //quantitySTR = new Double(et_dish_quan.getText().toString());
                quantitySTRtemp = Double.valueOf(cn.getQuantity());
            } catch (NumberFormatException e) {
                quantitySTRtemp = 0.0; // your default value
            }

            try {
                //costSTR = new Double(et_menucost.getText().toString());
                costSTRtemp =Double.valueOf(cn.getCost());
            } catch (NumberFormatException e) {
                costSTRtemp = 0.0; // your default value
            }
            Double resultSTR = quantitySTRtemp * costSTRtemp;


            sum = sum + (resultSTR);
        }
       Log.d("sum",""+sum);
    }

**CartAdapter.java**

 public View getView(final int position, View convertView, ViewGroup parent) 
{
        // Declare Variables

        final TextView et_menuname, et_menucost, et_dish_quan;
        Button btn_increment, btn_decrement;
        final TextView totalET, costET, QuantityET;
        ImageView img_dishtype;
        final String rupee;
        rupee = context.getString(R.string.Rs);
        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View itemView = inflater.inflate(R.layout.usercustomlistview, parent, false);
        resultp = data.get(position);
        btn_increment = (Button) itemView.findViewById(R.id.increment_btn);
        btn_decrement = (Button) itemView.findViewById(R.id.decrement_btn);
        totalET = (TextView) itemView.findViewById(R.id.ptotal);
        et_menuname = (TextView) itemView.findViewById(R.id.Dish_NameET);
        et_menucost = (TextView) itemView.findViewById(R.id.dish_costET);
        et_dish_quan = (TextView) itemView.findViewById(R.id.Dish_quantityET);

        et_menuname.setText(resultp.get("name"));
        et_menucost.setText(resultp.get("cost"));
        et_dish_quan.setText(resultp.get("quantity"));
        try {
            //quantitySTR = new Double(et_dish_quan.getText().toString());
            quantitySTR = Double.parseDouble(et_dish_quan.getText().toString());
        } catch (NumberFormatException e) {
            quantitySTR = 1.0; // your default value
        }
        try {
            //costSTR = new Double(et_menucost.getText().toString());
            costSTR = Double.parseDouble(et_menucost.getText().toString());
        } catch (NumberFormatException e) {
            costSTR = 1.0; // your default value
        }
        resultSTR = costSTR * quantitySTR;

        stringdouble = Double.toString(resultSTR);
        totalET.setText(stringdouble);

        empname = (resultp.get("name"));

        btn_increment.setOnClickListener(new View.OnClickListener() {
            boolean showText = false;

            @Override
            public void onClick(View v) {
                resultp = data.get(position);


                counter += 1;
                showText = true;
                if (counter == 1 || counter < 1) {
                    et_dish_quan.setText("1");
                } else {
                    et_dish_quan.setText(String.valueOf(counter));
                }

                try {
                    quantitySTR = new Double(et_dish_quan.getText().toString());
                } catch (NumberFormatException e) {
                    quantitySTR = 1.0; // your default value
                }
                try {
                    costSTR = new Double(et_menucost.getText().toString());
                } catch (NumberFormatException e) {
                    costSTR = 1.0; // your default value
                }
                resultSTR = costSTR * quantitySTR;
                final String stringdouble = Double.toString(resultSTR);
                totalET.setText(stringdouble);
                //db.updateOrder(TABLE_ORDERS, cv, "_id=" + id, null);
               tempcost = Double.toString(costSTR);
               tempquan = Double.toString(counter);

                db.addOrder(new Order(empname, tempcost, tempquan));
            }
        });
        btn_decrement.setOnClickListener(new View.OnClickListener() {
            boolean showText = false;

            @Override
            public void onClick(View v) {
                resultp = data.get(position);
                counter--;
                showText = true;
                if (counter == 1 || counter < 1) {
                    et_dish_quan.setText("1");
                } else {
                    et_dish_quan.setText(String.valueOf(counter));
                }
                try {
                    quantitySTR = new Double(et_dish_quan.getText().toString());
                } catch (NumberFormatException e) {
                    quantitySTR = 1.0; // your default value
                }
                try {
                    costSTR = new Double(et_menucost.getText().toString());
                } catch (NumberFormatException e) {
                    costSTR = 1.0; // your default value
                }
                resultSTR = costSTR * quantitySTR;
                final String stringdouble = Double.toString(resultSTR);
                totalET.setText(stringdouble);
                tempcost = Double.toString(costSTR);
               tempquan = Double.toString(counter);

                db.addOrder(new Order(empname,tempcost,tempquan));
                Log.d("Insert: ", "Inserting ..");
                //uc.calculateSum();

            }

        });
        return itemView;
    }

litiview项目的总和（resultSTR）。我想做resutstr的添加。我得到了成本和数量的总价值。

Answer 1

//Your Activity class will be like this:-

    public class MainActivity extends AppCompatActivity {
    ArrayList<String> listValues;
    ListView listView;
    TextView textView;
      @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            listview=(ListView)findViewById(R.id.list);
            textView=(TextView)findViewById(R.id.textView);
            listValues=new ArrayList<String>();
            listValues.add("1");
            listValues.add("2");
            listValues.add("3");
            listView= (ListView) findViewById(R.id.list);
            customAdapter= new CustomAdapter(MainActivity.this, R.layout.myview, listValues);
            listView.setAdapter(customAdapter);
    }

    //Create a method like below in your activity class

        public void updateValue(String amount)
        {
        textView.setText(amount);
        }

您的适配器将是这样的： -

    private ArrayList<Currency> values;
    private Context context;
    public CustomAdapter(Context context, int textViewResourceId,
                           ArrayList<String> values) {
            super(context, textViewResourceId, values);
            this.values=values;
            this.context=context;
    }

     @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View row = inflater.inflate(R.layout.spinner, parent, false);
            tempValues = null;
            tempValues = values.get(position);
            TextView label = (TextView) row.findViewById(R.id.tvLabel);
            Button button=(Button)row.findViewById(R.id.convert);
            label.setText(values.get(position));
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    int calculatedValue=Integer.parseInt(label.getText().toString())*2;
                    if(context instanceof MainActivity)
                    {
    //Update your calculated value in activity textview    
    ((MainActivity)context).update(String.valueOf(calculatedValue));
                }
            }
        });
        return row;
    }

Answer 2

制作如下界面：

   public interface ChangeItemInterface {

        public void doChange(float anyValue);

    }

在适配器中，

初始化接口对象，如：

ChangeItemInterface changeItemInterface;

在适配器构造函数中，

this.changeItemInterface = context;

在适配器中，从任何视图单击：

AnyView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                 // Do total here and that value pass to the Activity via interface method like below

                 this.changeItemInterface.doChange(<AnyValue>);
                 // It will go to the Your Activity Overided method which is explained below this


            }
        });

在您的活动中实现此界面，如：

     public class YourActivity extends Activity implements ChangeItemInterface{

        /// You'll get override method of your interface, here your call back will come when from adapter click happen
         @Override
            public void doChange(float anyValue) {

              /// Here you can update any value in your activity !

              /// Here you can pass total value and update in your activity class
            }

        }

希望这能帮助您解决问题！

是否可以将TextView添加到适配器类并将结果存储在活动类中

2 个答案: