我想创建一个显示用户订单的ListView。在下面的代码中,我得到了"成功"的作品,但我无法显示订单数组。
public void getOrderList() {
SharedPreferences sharedPreferences = getSharedPreferences("UserData", Context.MODE_PRIVATE);
final String hpno = sharedPreferences.getString("hpno", DEFAULT);
final OrderAdapter orderAdapter = new OrderAdapter(this, R.layout.row_layout);
orderIdListView.setAdapter(orderAdapter);
Response.Listener<String> responseListener = new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
boolean success = jsonResponse.getBoolean("success");
if (success) {
JSONArray orderList = new JSONArray(response);
for (int i = 0; i < orderList.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
JSONObject object = orderList.getJSONObject(i);
map.put("order_id", "Order Number: " + object.getString("order_id"));
orderAdapter.add(map);
}
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(ViewOrderActivity.this);
builder.setMessage("Order(s) Failed to be retrieved")
.setNegativeButton("Retry", null)
.create()
.show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
};
ViewOrderRequest viewOrderRequest = new ViewOrderRequest(hpno, responseListener);
RequestQueue queue = Volley.newRequestQueue(ViewOrderActivity.this);
queue.add(viewOrderRequest);
}
订单适配器:
public class OrderAdapter extends ArrayAdapter {
List list = new ArrayList();
public OrderAdapter(Context context, int resource) {
super(context, resource);
}
public void add(Order order) {
list.add(order);
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.add(position);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row;
row = convertView;
OrderHolder orderHolder;
if (row == null) {
LayoutInflater layoutInflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = layoutInflater.inflate(R.layout.row_layout, parent, false);
orderHolder = new OrderHolder();
orderHolder.orderIdText = (TextView) row.findViewById(R.id.orderIdText);
row.setTag(orderHolder);
} else {
orderHolder = (OrderHolder) row.getTag();
}
Order order = (Order) this.getItem(position);
orderHolder.orderIdText.setText(order.getOrder_id());
return row;
}
static class OrderHolder {
TextView orderIdText;
}
}
我的PHP代码:
<?php
require "init.php";
$hpno = $_POST['hpno'];
$statement = mysqli_prepare($con, "SELECT * FROM `Order` WHERE hpno = ?") or die(mysqli_error($con));
mysqli_stmt_bind_param($statement, "s", $hpno);
mysqli_stmt_execute($statement);
mysqli_stmt_store_result($statement);
mysqli_stmt_bind_result($statement, $order_id, $total_price, $quantity, $payment_status, $hpno, $menu_id, $ordered_on);
$response = array();
$response["success"] = false;
while(mysqli_stmt_fetch($statement)){
$response["success"] = true;
array_push($response, array("order_id"=>$order_id, "total_price"=>$total_price, "quantity"=>$quantity));
}
echo json_encode($response);
?>
JSON返回:
{
"success": true,
"0": {
"order_id": 21,
"total_price": 6,
"quantity": 1
},
"1": {
"order_id": 22,
"total_price": 18,
"quantity": 3
},
"2": {
"order_id": 23,
"total_price": 25,
"quantity": 5
},
"3": {
"order_id": 24,
"total_price": 35,
"quantity": 5
}
}
LOGCAT:
04-19 22:43:17.280 15452-15452/wqyap762.rprqs W/System.err: org.json.JSONException: Value {"success":true,"0":{"order_id":21,"total_price":6,"quantity":1},"1":{"order_id":22,"total_price":18,"quantity":3},"2":{"order_id":23,"total_price":25,"quantity":5},"3":{"order_id":24,"total_price":35,"quantity":5}} of type org.json.JSONObject cannot be converted to JSONArray
错误来自以下行:
JSONArray orderList = new JSONArray(response);
我一直在使用许多方法从数据库中检索,但都不起作用。
您的JSON格式不正确。如果你想让你的代码按预期工作,你的JSON应该是:
{
"success": true,
"values": [ {
"order_id": 21,
"total_price": 6,
"quantity": 1
},
{
"order_id": 22,
"total_price": 18,
"quantity": 3
},
{
"order_id": 23,
"total_price": 25,
"quantity": 5
},
{
"order_id": 24,
"total_price": 35,
"quantity": 5
}]
}
你的代码类似于:
JSONArray orderList = new JSONArray(response.getJSONArray("values"));
首先,您需要通知适配器的更改
if (success) {
JSONArray orderList = new JSONArray(response);
for (int i = 0; i < orderList.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
JSONObject object = orderList.getJSONObject(i);
map.put("order_id", "Order Number: " + object.getString("order_id"));
orderAdapter.add(map);
}
oderAdapter.notifyDataSetChanged();
}
其次,这个错误很容易理解,您正试图将json解析为JSONObject类型的JSONArray。
正如@Benoit所说,当你从数据库中获取数据时,你应该改变你的响应,并在他写时以数组的形式获得值
这里有一个问题,它解释了如何将数据库结果解析为json数组
如何从mysql数据库构建JSON数组