如何在每次單擊按鈕時使用自定義適配器將項目添加到列表視圖？

Question

我想要做的是看起來像添加到購物車的東西，但在我的Android應用程序，首先我已添加到購物車活動 ，其中有我需要的所有值，當我按下按鈕我發送我的數據為額外的購物車 列表活動，它顯示在行上，每次按下某個項目上的按鈕，它清除陣列，只顯示一行！ 但我真正需要做的是每當我按下按鈕我希望它添加到以前的項目並顯示所有..這是我的添加到購物車活動：

public class AddToCart extends Activity{

    EditText quantity=null;
    TextView total=null;
    TextView name=null;
    TextView price=null;
    TextView ava=null;
    double totalprice=0.0;

    ArrayList<String> listOfItemNames = new ArrayList<String>();
    List<listClass>testList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.info);
        Intent test = getIntent();



        Intent intent = getIntent();
        final String itemprice = intent.getStringExtra("price");
        final String itemname = intent.getStringExtra("item");
        final String itemava = intent.getStringExtra("ava");
        final int imagehandler=intent.getIntExtra("image", 0);
        Log.e("image handler",imagehandler+"");
         name=(TextView)findViewById(R.id.textView2);
         price=(TextView)findViewById(R.id.textView4);
         total=(TextView)findViewById(R.id.textView7);
         ava=(TextView)findViewById(R.id.textView9);
        quantity=(EditText)findViewById(R.id.editText1);
        Button addtocart=(Button)findViewById(R.id.button1);
        ImageView imageview=(ImageView)findViewById(R.id.imageView1);

        name.setText(itemname);
        price.setText(itemprice);
        ava.setText(itemava);
        imageview.setImageResource(imagehandler);



            addtocart.setOnClickListener(new OnClickListener() {


                @Override
                public void onClick(View v) {
                    final String quantityvalue=quantity.getText().toString();
                    CharSequence currentavaiable=ava.getText();
                    int currentava=Integer.parseInt((String) currentavaiable);
                    Editable checked = quantity.getText();
                    String checkquantity=checked.toString();
                    Log.e("checked ",checked+"");
                    Log.e("check quantity",checkquantity);
                    try{

                if(checkquantity==null){
                    Toast.makeText(AddToCart.this,"please enter quantity for your item", Toast.LENGTH_LONG).show();
                }

                else{
                    int x=0;
                    double y=0.0;
//                  String xvalue=quantity.getText().toString();
                     x = Integer.parseInt(quantityvalue);
                     Log.e("x",x+"");
                     y = Double.parseDouble(itemprice);
                    Log.e("x",x+"");
                    Log.e("y",y+"");
                     totalprice=x*y;
                    total.setText(totalprice+"");
                    Toast.makeText(AddToCart.this,"your item added succesfully !", Toast.LENGTH_LONG).show();

                }

                Intent newintent=new Intent(AddToCart.this,CartList.class);
                newintent.putExtra("itemname",itemname);
                newintent.putExtra("itemprice",itemprice);
                newintent.putExtra("itemquantity",quantityvalue);
                newintent.putExtra("totalprice",totalprice);
                newintent.putExtra("image", imagehandler);

                startActivity(newintent);
                }//view
                    catch(Exception e){
                        e.printStackTrace();
                    }
                }
            });
    }
}

這是購物車清單類：

public class CartList extends Activity {  
    ListView list;

    List<CartItems> detailsList = new ArrayList<CartItems>();
    ArrayList<String> listtest=new ArrayList <String>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.cart_list);





        initializeComponents();

        detailsList = SetAdapterList();

        CustomAdapter adapter=new CustomAdapter(this,detailsList);

        list.setAdapter(adapter);




    }


    private void initializeComponents()
    {
        list=(ListView)findViewById(R.id.listView1);
    }







    private List<CartItems> SetAdapterList() 
    {
        // TODO Auto-generated method stub

        CartItems details;

         List<CartItems> detailsList = new ArrayList<CartItems>();

         try{
         Intent newintent = getIntent();
         final String itemname = newintent.getStringExtra("itemname");
        final String itemprice = newintent.getStringExtra("itemprice");
        final String itemquantity = newintent.getStringExtra("itemquantity");
        final double totalprice = newintent.getDoubleExtra("totalprice", 0.0);
        String totprice=String.valueOf(totalprice);
//      ArrayList <String> itemnames=new ArrayList<String>();
         listtest.add(itemname);
         Log.e("listtest",listtest+"");
        final int imagehandler=newintent.getIntExtra("image", 0);
        Log.e("image handler",imagehandler+"");
        for(int i = 0; i< listtest.size(); i++)
        {
        details = new CartItems(itemname,itemprice,itemquantity,totprice,imagehandler);
        detailsList.add(details);
        }


         }
         catch(Exception e){
             e.printStackTrace();
         }      
            return detailsList;
    }   

}

這是我的自定義適配器：

public class CustomAdapter extends ArrayAdapter<CartItems> {

    Context context;
    List<CartItems>Clist = new ArrayList<CartItems>();

    public CustomAdapter(Context context, List<CartItems> detailsList) {
        super(context, R.layout.single_row, R.id.textView1, detailsList);
        // TODO Auto-generated constructor stub

        this.context=context;
        this.Clist = detailsList;


    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        LayoutInflater inflater=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View row=inflater.inflate(R.layout.single_row, parent,false);
        ImageView myimage=(ImageView) row.findViewById(R.id.imageView1);
        TextView items=(TextView)row.findViewById(R.id.textView1);
        TextView totalprice=(TextView)row.findViewById(R.id.textView2);



        items.setText(Clist.get(position).getItemName());
        totalprice.setText(Clist.get(position).getTotalPrice());
        myimage.setImageResource(Clist.get(position).getImage());

        return row;
    }

}

這是我的itemcart類：

public class CartItems {

    private String itemName;
    private String itemPrice;
    private String Quantity;
    private String totalPrice;
    private int image;

    public CartItems(String itemname,String itemprice, String quantity, String totalprice2, int image){
        this.itemName=itemname;
        this.itemPrice=itemprice;
        this.Quantity=quantity;
        this.totalPrice=totalprice2;
        this.image=image;
    }
//getter and setters 
}

請有人可以幫幫我嗎？ 我很絕望!!

Answer 1

你正在重置你的arraylist everyime。 相反，每次選擇項目時都會向其添加項目。 跟着這些步驟：

1）將你的setadapter函數更改為return item，而不是itemlist。

private CartItems SetAdapterList() 
    {
        // TODO Auto-generated method stub

        CartItems details;
      try{
         Intent newintent = getIntent();
         final String itemname = newintent.getStringExtra("itemname");
        final String itemprice = newintent.getStringExtra("itemprice");
        final String itemquantity = newintent.getStringExtra("itemquantity");
        final double totalprice = newintent.getDoubleExtra("totalprice", 0.0);
        String totprice=String.valueOf(totalprice);
//      ArrayList <String> itemnames=new ArrayList<String>();
         listtest.add(itemname);
         Log.e("listtest",listtest+"");
        final int imagehandler=newintent.getIntExtra("image", 0);
        Log.e("image handler",imagehandler+"");
        for(int i = 0; i< listtest.size(); i++)
        {
        details = new CartItems(itemname,itemprice,itemquantity,totprice,imagehandler);

        }


         }
         catch(Exception e){
             e.printStackTrace();
         }      
            return details;
    }   

2）獲得此值后，只需將其添加到您的arraylist。 像這樣：

CartItems item = SetAdapterList();
detailsList.add(item);

現在，當您填充listView時，detailsList也將包含所有先前選擇的項目。 如果要重置，只需清除detailsList。

Answer 2

1）將新項添加到您的detailsList。

2）為適配器調用notifyDataSetChanged() 。