在android上需要帮助=（多年来一直被困在这个问题上！我的代码如图所示。
public class AllUsersActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> usersList;
// url to get all users list
private static String url_all_users = "http://10.0.2.2/android_connect/get_all_users.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_USERS = "users";
private static final String TAG_UID = "UserID";
private static final String TAG_FIRSTNAME = "FirstName";
// users JSONArray
JSONArray users = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_users);
// Hashmap for ListView
usersList = new ArrayList<HashMap<String, String>>();
// Loading users in Background Thread
new LoadAllusers().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String uid = ((TextView) view.findViewById(R.id.uid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
UserDetailsActivity.class);
// sending uid to next activity
in.putExtra(TAG_UID, uid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllusers extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllUsersActivity.this);
pDialog.setMessage("Loading users. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All users from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_users, "GET", params);
// Check your log cat for JSON reponse
Log.d("All users: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// users found
// Getting Array of users
users = json.getJSONArray(TAG_USERS);
// looping through All users
for (int i = 0; i < users.length(); i++) {
JSONObject c = users.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_UID);
String name = c.getString(TAG_FIRSTNAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_UID, id);
map.put(TAG_FIRSTNAME, name);
// adding HashList to ArrayList
usersList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all users
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllUsersActivity.this, usersList,
R.layout.list_item, new String[] { TAG_UID,
TAG_FIRSTNAME},
new int[] { R.id.uid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
谁能帮帮我吗！我得到的错误是Error Parsing Data Org.json.JSONException: Value cannot be convert to JSONObject
这是 JSON 字符串
Array{"Users":[{"UserID":"1","FirstName":"lalawee","Email":"12345","Password":null},{"UserID":"2","FirstName":"shadowblade721","Email":"12345","Password":null},{"UserID":"3","FirstName":"dingdang","Email":"12345","Password":null},{"UserID":"4","FirstName":"solidsnake0328","Email":"12345","Password":null}],"success":1}
错误是否存在于 JSON 解析器类中？
编辑：这里是输出上述数组的 php 脚本的代码。谁能告诉我在 json 字符串之前输出单词数组的 php 脚本有什么问题？抱歉，添麻烦了。我是编码新手。一直在关注在线教程，但现在坚持了几天。
<?php
/*
* Following code will list all the Users
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// get all Users from Users table
$result = mysql_query("SELECT * FROM Users") or die(mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// looping through all results
// Users node
$response["Users"] = array();
while ($row = mysql_fetch_array($result)) {
// temp user array
$user[] = array();
$user["UserID"] = $row["UserID"];
$user["FirstName"] = $row["FirstName"];
$user["Email"] = $row["Email"];
$user["Password"] = $row["Password"];
// push single User into final response array
array_push($response["Users"], $user);
}
// success
$response["success"] = 1;
echo $response;
// echoing JSON response
echo json_encode($response);
}
else {
// no Users found
$response["success"] = 0;
$response["message"] = "No Users found";
// echo no users JSON
echo json_encode($response);
}
?>