我正在使用适配器从listview中检索数据

时间:2016-07-01 01:17:10

标签: android listview custom-adapter

我可以在我的menuactivity中显示toast,但现在我需要从listview获取所选数据并将其显示在另一页面上。我已经尝试了很多方法并搜索它但我似乎无法得到它。

menuactivity:

    public class MenuActivity extends Activity {


    private String server = "http://172.16.156.56";
    private String sql_table = "orders";
    private ListView list;
    private TextView txtOrder, txtMember, txtPrice;
    private Button btnAdd;
    ArrayList<String> rows;

    ListView listView1;
    Button btnSubmit;
    ArrayList<CustomItem> itemList, selectedList;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_menu);


        list=(ListView) findViewById(R.id.listView);
        btnAdd = (Button)findViewById(R.id.button);
        rows = new ArrayList<String>();


        itemList=new ArrayList<CustomItem>();
        itemList.add(new CustomItem("Fried Rice","description","1","Quantity"));
        itemList.add(new CustomItem("Fried Noodle","description","2","Quantity"));
        itemList.add(new CustomItem("Prawn noodle","description","3","Quantity"));
        itemList.add(new CustomItem("Chicken Rice","description","4","Quantity"));

        int[] prgmImages={R.drawable.friedrice,R.drawable.friednoodle,R.drawable.pnoodle,R.drawable.chickenrice};

        listView1 = (ListView) findViewById(R.id.listView);
        final CustomLVAdapter customLVAdapter = new CustomLVAdapter(this, itemList,prgmImages);
        listView1.setAdapter(customLVAdapter);


        txtOrder = (TextView) findViewById(R.id.txt1);
        txtMember = (TextView) findViewById(R.id.txt2);
        txtPrice = (TextView) findViewById(R.id.txt3);


        btnSubmit = (Button) findViewById(R.id.button);


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



                StringBuffer responseText = new StringBuffer();
                selectedList = new ArrayList<CustomItem>();
                int total = 0;
                for (int i = 0; i < itemList.size(); i++) {
                    CustomItem object = itemList.get(i);
                    if (object.isSelected()) {
                        responseText.append(object.getItem() + "," + object.getQty() + ",");//item
                        selectedList.add(object);
                        //calculate price
                        total = total + Integer.parseInt(object.getQty()) * Integer.parseInt(object.getPrice());

                    }


                }
                Add(responseText.toString(), "5565", String.valueOf(total));


                Intent i = new Intent(v.getContext(), ReceiptActivity.class);



                startActivity(i);




                Toast.makeText(getApplicationContext(), responseText + " $" + total,
                        Toast.LENGTH_SHORT).show();


                SelectAll();
                //store in database

                //go to ReceiptActivity - membership, item, totalprice

            }
        });


    }





    public void Add(final String item, final String membership, final String price)
    {
        RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
        String url = server + "/insertorder.php";
        StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
            }
        }) {
            protected Map<String, String> getParams() {
                Map<String, String> MyData = new HashMap<String, String>();
                MyData.put("item",item );
                MyData.put("membership",membership );
                MyData.put("price",price );

                return MyData;
            }
        };
        MyRequestQueue.add(MyStringRequest);
        SelectAll();
    }
    public void SelectAll()
    {
        RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
        String url = server + "/fetchorder.php";
        StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    JSONObject jsonResponse = new JSONObject(response);
                    JSONArray jsonMainNode = jsonResponse.optJSONArray(sql_table);
                    rows.clear();
                    for(int i=0; i < jsonMainNode.length(); i++)
                    {
                        JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
                        String order       = jsonChildNode.optString("item").toString();
                        String membership     = jsonChildNode.optString("membership").toString();
                        String price = jsonChildNode.optString("price").toString();

                        rows.add(order + ", " + membership + ", " + price );
                    }
                    ArrayAdapter<String> adapter = new ArrayAdapter<String>(MenuActivity.this,
                            android.R.layout.simple_list_item_1, rows);
                    list.setAdapter(adapter);

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() { //Create an error listener to handle errors appropriately.
            @Override
            public void onErrorResponse(VolleyError error) {
                //This code is executed if there is an error.
            }
        });
        MyRequestQueue.add(MyStringRequest);
    }



}

收据活动(我想显示结果的页面)

public class ReceiptActivity extends Activity {
static public String txtOrder = "";
TextView foodorder;
ArrayList<CustomItem> itemList, selectedList;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_receipt);


    CustomLVAdapter item = (CustomLVAdapter) parent.getItemAtPosition(position);

    TextView foodorder = (TextView)findViewById(R.id.foodorder);
    foodorder.setText("Order:" +strOrder+" ");

自定义适配器

 public class CustomLVAdapter extends BaseAdapter {

    private Context context;
    LayoutInflater inflater;
    private ArrayList<CustomItem> objectList;
    private int[] imageId;
    public static ArrayList<CustomItem> arl_food=new ArrayList<>();

    private class ViewHolder {
        TextView txt1,txt2,txt3;
        CheckBox ckBox;
        ImageView image;

        NumberPicker np;
    }




    public CustomLVAdapter(Context context, ArrayList<CustomItem> objectList,int[]prgmImages){
        this.context = context;
        this.inflater = LayoutInflater.from(context);
        this.objectList = objectList;
        this.imageId = prgmImages;


    }

    public int getCount(){
        return objectList.size();
    }

    public CustomItem getItem (int position) {
        return objectList.get(position);
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;


        if (convertView == null) {
            holder = new ViewHolder();
            convertView = inflater.inflate(R.layout.row_checkbox_textview, null);
            holder.txt1 = (TextView) convertView.findViewById(R.id.txt1);
            holder.txt2 = (TextView) convertView.findViewById(R.id.txt2);
            holder.txt3 = (TextView) convertView.findViewById(R.id.txt3);
            holder.image=(ImageView) convertView.findViewById(R.id.image);
            holder.ckBox = (CheckBox) convertView.findViewById(R.id.ckBox);
            holder.np  = (NumberPicker) convertView.findViewById(R.id.numberPicker);
            holder.np.setMinValue(0);
            holder.np.setMaxValue(10);






            convertView.setTag(holder);

            holder.ckBox.setOnClickListener(new View.OnClickListener() {
                                                public void onClick(View v) {
                                                    CheckBox cb = (CheckBox) v;
                                                    CustomItem object = (CustomItem) cb.getTag();
                                                    Toast.makeText(context,
                                                            "You have selected:  " + object.getItem() +
                                                                    "Price: " + object.getPrice() +
                                                                    "Qty: " + object.getQty(),
                                                            Toast.LENGTH_LONG).show();
                                                    object.setSelected(cb.isChecked());

                                                }
                                            }
            );

            holder.np.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
                @Override
                public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
                    NumberPicker p = picker;
                    CustomItem object = (CustomItem) p.getTag();
                    object.setQty(String.valueOf(newVal));

                }
            });
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        CustomItem object = objectList.get(position);
        holder.txt1.setText(object.getItem());
        holder.txt2.setText(object.getDesc());
        holder.txt3.setText(object.getPrice());

        holder.np.setTag(object);
        holder.image.setImageResource(imageId[position]);
        holder.ckBox.setChecked(object.isSelected());
        holder.ckBox.setTag(object);

        return convertView;
    }
}

1 个答案:

答案 0 :(得分:0)

单击提交按钮时,您似乎已经开始活动了。现在你所要做的就是在你正在创造的意图中传递一些额外的东西。

因此,当你做出意图时,你也应该这样做:

...
Intent i = new Intent(v.getContext(), ReceiptActivity.class);
i.putExtra("PRICE", price);
i.putExtra("MEMBERSHIP", membership);
i.putExtra("ITEM", item);
startActivity(i);
...

然后在您的新活动中,您将在onCreate方法中读出额外内容,如下所示:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_receipt);
    int price = getIntent().getStringExtra("PRICE");
    String membership = getIntent().getStringExtra("MEMBERSHIP");
    CustomItem item = getIntent().getStringExtra("ITEM");
    ...

一个警告!看起来您使用对象CustomItem表示您的项目。为了将其作为额外传递,它必须实现Parcelable。实现Parcelable时,您将定义如何将对象及其字段转换为“parcel”以及如何将“parcel”转回到对象中。它的google docs give a pretty good example

我撒了谎,另一个警告!我建议您在ReceiptActivity中为附加组件“public static final String”创建密钥。这样你就可以更轻松地管理它们。