java Android ListView单击以创建新活动
我的应用程序获取产品的条形码id，并将产品所在市场的价格反馈给我。 在listview中，我有市场和价格。 当我单击listview元素时，我想继续执行新的活动，其中市场详细信息应打印到textview或其他内容。。 但是，当我单击元素时，emulator崩溃，如“不幸停止”
这里是我的java代码、php代码和日志； （我从上一个活动中提取条形码，并将市场名称发送到下一个活动，以执行必要的json、php、db查询）
public class Query_product extends ListActivity {
JSONArray products = null;
JSONParser jParser = new JSONParser();
String pid;
String market;
// Progress Dialog
private ProgressDialog pDialog;
ArrayList<HashMap<String, String>> productsList;
// Creating JSON Parser object
JSONParser jsonParser = new JSONParser();
// url to get all products list
private static final String url_market = "http://furkan.feramor.gen.tr/webservice/enucuz.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "barcode";
private static final String TAG_NAME = "name";
private static final String TAG_PRICE = "price";
private static final String TAG_DESCRIPTION = "description";
private static final String TAG_MARKET = "mname";
// products JSONArray
JSONArray product = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
productsList = new ArrayList<HashMap<String, String>>();
pid = getIntent().getExtras().getString(Constants.ID);
new GetProductDetails().execute();
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
// String mName = ((TextView) view.findViewById(R.id.marketName)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext() , Market_details.class);
in.putExtra("market", market);
Log.d("aaaaaa",market);
// starting new activity
startActivity(in);
}
});
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class GetProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Query_product.this);
pDialog.setMessage("Loading product details. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Getting product details in background thread
* */
protected String doInBackground(String... params) {
List<NameValuePair> params1 = new ArrayList<NameValuePair>();
params1.add(new BasicNameValuePair(TAG_PID, pid));
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_market, "GET", params1);
// Log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
market = c.getString(TAG_MARKET);
String price = c.getString(TAG_PRICE);
//////// String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_MARKET, market);
map.put(TAG_PRICE, price);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
menu.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} 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 products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(Query_product.this, productsList,
R.layout.list_item, new String[] { TAG_MARKET, TAG_PRICE }, new int[] {R.id.marketName, R.id.price });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
php:
<?php
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
if (isset($_GET["barcode"])) {
$barcode = $_GET['barcode'];
$result = mysql_query("SELECT *, markets.mname
FROM products
INNER JOIN markets ON products.marketid = markets.marketid
WHERE barcode = '$barcode'
ORDER BY price") or die (mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// looping through all results
// products node
$response["products"] = array();
while ($row = mysql_fetch_array($result)) {
// temp user array
$product = array();
$product["barcode"] = $row["barcode"];
$product["name"] = $row["name"];
$product["description"] = $row["description"];
$product["price"] = $row["price"];
$product["created_at"] = $row["created_at"];
$product["updated_at"] = $row["updated_at"];
$product["mname"]= $row["mname"];
// push single product into final response array
array_push($response["products"], $product);
}
// success
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
// no products found
$response["success"] = 0;
$response["message"] = "No products found";
// echo no users JSON
echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
// echoing JSON response
echo json_encode($response);
}
?>
市场详细信息java类：
public class Market_details extends Activity {
TextView txtMarketName, txtMarketLoc;
JSONArray markets = null;
String marketName;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// single product url
private static final String url_market_details = "http://furkan.feramor.gen.tr/webservice/marketinfo.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_MARKET = "mname";
private static final String TAG_MARKETLOC = "mloc";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.market_detail);
// getting market name from intent
marketName = getIntent().getExtras().getString("market");
Log.d("bbbbbbb",marketName);
// Getting market details in background thread
new GetMarketDetails().execute();
}
/**
* Background Async Task to Get complete product details
* */
class GetMarketDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
Log.d("CCC","A");
super.onPreExecute();
pDialog = new ProgressDialog(Market_details.this);
pDialog.setMessage("Loading market details. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
Log.d("DDD","");
}
/**
* Getting product details in background thread
* */
protected String doInBackground(String... params) {
Log.d("EEE","");
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
// Check for success tag
int success;
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("mname", marketName));
Log.d("FFF","");
// getting product details by making HTTP request
// Note that product details url will use GET request
JSONObject json = jsonParser.makeHttpRequest(
url_market_details, "GET", params);
Log.d("GGG","");
// check your log for json response
Log.d("Single Market Details", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully received product details
Log.d("HHHH","");
markets = json.getJSONArray(TAG_PRODUCTS);
for (int i = 0; i < markets.length(); i++) {
JSONObject c = markets.getJSONObject(i);
String marketname = c.getString(TAG_MARKET);
String marketloc = c.getString(TAG_MARKETLOC);
Log.d("ccccccc",marketname);
txtMarketName = (TextView) findViewById(R.id.marketname);
txtMarketLoc = (TextView) findViewById(R.id.marketloc);
txtMarketName.setText(marketname);
txtMarketLoc.setText(marketloc);
Log.d("KKKK","");
}
}else{
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once got all details
pDialog.dismiss();
}
}
}
这里是merketinfo。php:
<?php
/*
* Following code will get single market details
* A market is identified by market id (pid)
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// check for post data
if (isset($_POST["mname"])) {
$mname= $_POST['mname'];
// get a market from markets table
$result = mysql_query("SELECT * FROM markets WHERE mname = '$mname");
if (!empty($result)) {
// check for empty result
if (mysql_num_rows($result) > 0) {
$result = mysql_fetch_array($result);
$market = array();
$market["marketid"] = $result["marketid"];
$market["mname"] = $result["mname"];
$market["mtelno"] = $result["mtelno"];
$market["mloc"] = $result["mloc"];
// success
$response["success"] = 1;
// user node
$response["market"] = array();
array_push($response["markets"], $market);
// echoing JSON response
echo json_encode($response);
} else {
// no market found
$response["success"] = 0;
$response["message"] = "No market found";
// echo no users JSON
echo json_encode($response);
}
} else {
// no market found
$response["success"] = 0;
$response["message"] = "No market found";
// echo no users JSON
echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
// echoing JSON response
echo json_encode($response);
}
?>
这是我的日志：
12-24 17:17:15.783: D/libEGL(832): loaded /system/lib/egl/libEGL_emulation.so
12-24 17:17:15.793: D/(832): HostConnection::get() New Host Connection established 0x2a1dce88, tid 832
12-24 17:17:15.853: D/libEGL(832): loaded /system/lib/egl/libGLESv1_CM_emulation.so
12-24 17:17:15.873: D/libEGL(832): loaded /system/lib/egl/libGLESv2_emulation.so
12-24 17:17:15.973: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:17:15.993: D/OpenGLRenderer(832): Enabling debug mode 0
12-24 17:32:12.384: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:32:39.856: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:32:40.604: D/dalvikvm(832): GC_FOR_ALLOC freed 74K, 8% free 2946K/3176K, paused 293ms, total 394ms
12-24 17:32:46.194: D/dalvikvm(832): GC_FOR_ALLOC freed 37K, 6% free 3107K/3304K, paused 71ms, total 97ms
12-24 17:32:46.223: I/dalvikvm-heap(832): Grow heap (frag case) to 4.260MB for 1127536-byte allocation
12-24 17:32:46.393: D/dalvikvm(832): GC_FOR_ALLOC freed 1K, 5% free 4206K/4408K, paused 162ms, total 162ms
12-24 17:32:47.024: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:32:47.376: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:32:47.603: I/Choreographer(832): Skipped 44 frames! The application may be doing too much work on its main thread.
12-24 17:32:48.414: I/Choreographer(832): Skipped 41 frames! The application may be doing too much work on its main thread.
12-24 17:32:53.764: D/All Products:(832): {"success":1,"products":[{"mname":"KAS","created_at":"2013-12-24 14:17:13","barcode":"12345","updated_at":"0000-00-00 00:00:00","price":"2.00","description":"iyi","name":"mete"}]}
12-24 17:32:58.234: D/aaaaaa(832): KAS
12-24 17:32:59.014: D/bbbbbbb(832): KAS
12-24 17:32:59.024: D/CCC(832): A
12-24 17:32:59.683: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:33:00.404: W/EGL_emulation(832): eglSurfaceAttrib not implemented
12-24 17:33:00.923: D/AndroidRuntime(832): Shutting down VM
12-24 17:33:00.923: W/dalvikvm(832): threadid=1: thread exiting with uncaught exception (group=0x41465700)
12-24 17:33:01.586: E/AndroidRuntime(832): FATAL EXCEPTION: main
12-24 17:33:01.586: E/AndroidRuntime(832): 安卓.os.NetworkOnMainThreadException
12-24 17:33:01.586: E/AndroidRuntime(832): at 安卓.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
12-24 17:33:01.586: E/AndroidRuntime(832): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
12-24 17:33:01.586: E/AndroidRuntime(832): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
12-24 17:33:01.586: E/AndroidRuntime(832): at java.net.InetAddress.getAllByName(InetAddress.java:214)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-24 17:33:01.586: E/AndroidRuntime(832): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-24 17:33:01.586: E/AndroidRuntime(832): at com.example.ssa.JSONParser.makeHttpRequest(JSONParser.java:62)
12-24 17:33:01.586: E/AndroidRuntime(832): at com.example.ssa.Market_details$GetMarketDetails$1.run(Market_details.java:102)
12-24 17:33:01.586: E/AndroidRuntime(832): at 安卓.os.Handler.handleCallback(Handler.java:730)
12-24 17:33:01.586: E/AndroidRuntime(832): at 安卓.os.Handler.dispatchMessage(Handler.java:92)
12-24 17:33:01.586: E/AndroidRuntime(832): at 安卓.os.Looper.loop(Looper.java:137)
12-24 17:33:01.586: E/AndroidRuntime(832): at 安卓.app.ActivityThread.main(ActivityThread.java:5103)
12-24 17:33:01.586: E/AndroidRuntime(832): at java.lang.reflect.Method.invokeNative(Native Method)
12-24 17:33:01.586: E/AndroidRuntime(832): at java.lang.reflect.Method.invoke(Method.java:525)
12-24 17:33:01.586: E/AndroidRuntime(832): at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
12-24 17:33:01.586: E/AndroidRuntime(832): at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:553)
12-24 17:33:01.586: E/AndroidRuntime(832): at dalvik.system.NativeStart.main(Native Method)
12-24 17:33:01.924: D/dalvikvm(832): GC_FOR_ALLOC freed 174K, 7% free 4602K/4932K, paused 277ms, total 296ms
12-24 17:33:09.916: D/libEGL(871): loaded /system/lib/egl/libEGL_emulation.so
12-24 17:33:10.089: D/(871): HostConnection::get() New Host Connection established 0x2a1e0260, tid 871
12-24 17:33:10.164: D/libEGL(871): loaded /system/lib/egl/libGLESv1_CM_emulation.so
12-24 17:33:10.184: D/libEGL(871): loaded /system/lib/egl/libGLESv2_emulation.so
12-24 17:33:10.416: W/EGL_emulation(871): eglSurfaceAttrib not implemented
12-24 17:33:10.435: D/OpenGLRenderer(871): Enabling debug mode 0
# 1 楼答案
问题出在您的“市场详细信息”类中，其中： 受保护的字符串doInBackground（字符串…参数）{
。。。等等 使用doInBackground的原因是在后台线程中进行网络调用，但调用runOnUIThread会导致networkonmainthread异常。您不能使用网络（这是jsonParser.makeHttpRequest（url\u market\u details，“GET”，params）；在这种情况下，函数调用）只需删除runOnUI部分，并将所有代码移到doInBackground中即可
# 2 楼答案
我认为您不应该在}方法中调用
AsyncTask{runOnUiThread，这是在Market_details中我将在
doInBackground中完成所有繁重的网络工作，并在post方法中更新UI