我正在制作一个应用程序，在该应用程序中，我使用 JSON 将数据提取到 ListView 中，并允许用户以另一种形式（以 singleMenuItem 形式）查看所选项目。
我已经放置了一个按钮 - 添加到购物车。每当用户单击“添加到购物车”按钮时，所选项目需要显示在“查看购物车”表单中。对于添加到购物车的每个项目，将重复相同的过程。
我只想显示每个项目的标题和成本，对于那些我SingleMenuItem使用 Intent from ListViewForm 提取到表单中的项目，现在我想在查看购物车表单中显示如下：- 按操作顺序添加多个项目，问题是我不知道每次用户单击“添加到购物车”按钮时如何更新查看购物车表单。
目录（列表查看活动）代码：-
public class Catalogue extends Activity{
static String URL = "http:/--------/and/menu.json";
static String KEY_CATEGORY = "item";
static final String KEY_TITLE = "title";
static final String KEY_DESCRIPTION = "description";
static final String KEY_COST = "cost";
static final String KEY_THUMB_URL = "imageUri";
ListView list;
LazyAdapter adapter;
/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ArrayList<HashMap<String, String>> itemsList = new ArrayList<HashMap<String, String>>();
list=(ListView)findViewById(R.id.listView1);
adapter=new LazyAdapter(this, itemsList);
list.setAdapter(adapter);
Intent in = getIntent();
KEY_CATEGORY = in.getStringExtra("category");
try{
JSONArray jsonArray = json.getJSONArray(KEY_CATEGORY);
for(int i=0;i < jsonArray.length();i++){
HashMap<String, String> map = new HashMap<String, String>();
JSONObject jsonObject = jsonArray.getJSONObject(i);
map.put("id", String.valueOf(i));
map.put(KEY_TITLE, jsonObject.getString(KEY_TITLE));
map.put(KEY_DESCRIPTION, jsonObject.getString(KEY_DESCRIPTION));
map.put(KEY_COST, jsonObject.getString(KEY_COST));
map.put(KEY_THUMB_URL, jsonObject.getString(KEY_THUMB_URL));
itemsList.add(map);
}
return itemsList;
}catch(JSONException e) {
Log.e("log_tag", "Error parsing data "+e.toString());
}
return null;
}
@Override
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
list=(ListView)findViewById(R.id.listView1);
adapter=new LazyAdapter(Catalogue.this, itemsList);
list.setAdapter(adapter);
this.progressDialog.dismiss();
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
HashMap<String, String> map = itemsList.get(position);
Intent in = new Intent(Catalogue.this, SingleMenuItem.class);
in.putExtra(KEY_TITLE, map.get(KEY_TITLE));
in.putExtra(KEY_DESCRIPTION, map.get(KEY_DESCRIPTION));
in.putExtra(KEY_THUMB_URL, map.get(KEY_THUMB_URL));
in.putExtra(KEY_COST, map.get(KEY_COST));
startActivity(in);
}
});
ImageButton viewShoppingCart = (ImageButton) findViewById(R.id.ButtonViewCart);
viewShoppingCart.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent in = new Intent
(Catalogue.this, FinalOrder.class);
startActivity(in);
}
});
} }}
SingleMenuItem 活动代码
public class SingleMenuItem extends Activity{
static final String KEY_TITLE = "title";
static final String KEY_COST = "cost";
static final String KEY_THUMB_URL = "imageUri";
private EditText edit_qty_code;
private TextView txt_total;
private TextView text_cost_code;
private double itemamount = 0;
private double itemquantity = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.single);
Intent in = getIntent();
String title = in.getStringExtra(KEY_TITLE);
String thumb_url = in.getStringExtra(KEY_THUMB_URL);
final String cost = in.getStringExtra(KEY_COST);
ImageLoader imageLoader = new ImageLoader(getApplicationContext());
ImageView imgv = (ImageView) findViewById(R.id.single_thumb);
TextView txttitle = (TextView) findViewById(R.id.single_title);
TextView txtcost = (TextView) findViewById(R.id.single_cost);
TextView txtheader = (TextView) findViewById(R.id.actionbar);
txttitle.setText(title);
txtheader.setText(title);
txtcost.setText(cost);
imageLoader.DisplayImage(thumb_url, imgv);
ImageButton addToCartButton = (ImageButton) findViewById(R.id.img_add);
addToCartButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent in = new Intent
(SingleMenuItem.this, FinalOrder.class);
in.putExtra(KEY_TITLE, getIntent().getStringExtra(KEY_TITLE));
in.putExtra(KEY_COST, getIntent().getStringExtra(KEY_COST));
startActivity(in);
// Close the activity
finish();
}
});
}}
ViewCart 活动代码：-
public class FinalOrder extends Activity
{
static final String KEY_TITLE = "title";
static final String KEY_COST = "cost";
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view);
Intent in = getIntent();
String title1 = in.getStringExtra(KEY_TITLE);
String cost1 = in.getStringExtra(KEY_COST);
TextView txttitle1 = (TextView) findViewById(R.id.item_name);
TextView txtcost1 = (TextView) findViewById(R.id.item_cost);
txttitle1.setText(title1);
txtcost1.setText(cost1);
}
}