我正在开发一个Android应用程序...我在MySql中开发了一个表，并且表中的值为1-10的某些结果，并且所有值都单独输入...
在我的Android应用程序中显示特定值时，必须从表中获取该值的结果...但它无法正常工作...消息变得像“遗憾的应用程序已关闭”...我在这里添加我的代码...请检查代码，如果发现任何错误请帮助.....
Activity.java
public class FirstResult extends Activity
{
String pid;
TextView txtName;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// single product url
private static final String url_product_detials = "http://iascpl.com/app/get_product_details.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCT = "product";
//private static final String TAG_PID = "pid";
//private static final String TAG_NUMBER = "number";
//private static final String TAG_PRICE = "price";
private static final String TAG_DESCRIPTION = "description";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.firstresult_xm);
TextView txt1 = (TextView) findViewById (R.id.textView2);
txt1.setText(getIntent().getStringExtra("name10"));
pid = txt1.getText().toString();
new GetProductDetails().execute();
}
/**
* Background Async Task to Get complete product details
* */
class GetProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(FirstResult.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) {
// 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("pid", pid));
// getting product details by making HTTP request
// Note that product details url will use GET request
JSONObject json = jsonParser.makeHttpRequest(
url_product_detials, "GET", params);
// check your log for json response
Log.d("Single Product Details", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully received product details
JSONArray productObj = json
.getJSONArray(TAG_PRODUCT); // JSON Array
// get first product object from JSON Array
JSONObject product = productObj.getJSONObject(0);
// product with this pid found
// Edit Text
txtName = (TextView) findViewById(R.id.textView3);
// display product data in EditText
txtName.setText(product.getString(TAG_DESCRIPTION));
}else{
// product with pid not found
}
} 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();
}
}
}
php文件
<?php
/*
* Following code will get single product details
* A product is identified by product id (pid)
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// check for post data
if (isset($_GET["pid"])) {
$pid = $_GET['pid'];
// get a product from products table
$result = mysql_query("SELECT *FROM prediction WHERE pid = $pid");
if (!empty($result)) {
// check for empty result
if (mysql_num_rows($result) > 0) {
$result = mysql_fetch_array($result);
$product = array();
$product["pid"] = $result["pid"];
$product["number"] = $result["number"];
// $product["price"] = $result["price"];
$product["description"] = $result["description"];
$product["created_at"] = $result["created_at"];
$product["updated_at"] = $result["updated_at"];
// success
$response["success"] = 1;
// user node
$response["product"] = array();
array_push($response["product"], $product);
// echoing JSON response
echo json_encode($response);
} else {
// no product found
$response["success"] = 0;
$response["message"] = "No product found";
// echo no users JSON
echo json_encode($response);
}
} else {
// no product found
$response["success"] = 0;
$response["message"] = "No product found";
// echo no users JSON
echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
我的Logcat
11-05 11:44:12.701: E/AndroidRuntime(7643): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
11-05 11:44:12.701: E/AndroidRuntime(7643): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
11-05 11:44:12.701: E/AndroidRuntime(7643): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
11-05 11:44:12.701: E/AndroidRuntime(7643): at com.example.numero.JSONParser.makeHttpRequest(JSONParser.java:63)
11-05 11:44:12.701: E/AndroidRuntime(7643): at com.example.numero.FirstResult$GetProductDetails$1.run(FirstResult.java:105)
11-05 11:44:12.701: E/AndroidRuntime(7643): at android.os.Handler.handleCallback(Handler.java:725)
11-05 11:44:12.701: E/AndroidRuntime(7643): at android.os.Handler.dispatchMessage(Handler.java:92)
11-05 11:44:12.701: E/AndroidRuntime(7643): at android.os.Looper.loop(Looper.java:137)
11-05 11:44:12.701: E/AndroidRuntime(7643): at android.app.ActivityThread.main(ActivityThread.java:5041)
11-05 11:44:12.701: E/AndroidRuntime(7643): at java.lang.reflect.Method.invokeNative(Native Method)
11-05 11:44:12.701: E/AndroidRuntime(7643): at java.lang.reflect.Method.invoke(Method.java:511)
11-05 11:44:12.701: E/AndroidRuntime(7643): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
11-05 11:44:12.701: E/AndroidRuntime(7643): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
11-05 11:44:12.701: E/AndroidRuntime(7643): at dalvik.system.NativeStart.main(Native Method)
11-05 11:52:08.052: E/Trace(7805): error opening trace file: No such file or directory (2)
11-05 11:56:14.171: E/AndroidRuntime(7805): FATAL EXCEPTION: main
11-05 11:56:14.171: E/AndroidRuntime(7805): android.os.NetworkOnMainThreadException
11-05 11:56:14.171: E/AndroidRuntime(7805): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
11-05 11:56:14.171: E/AndroidRuntime(7805): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
11-05 11:56:14.171: E/AndroidRuntime(7805): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
11-05 11:56:14.171: E/AndroidRuntime(7805): at java.net.InetAddress.getAllByName(InetAddress.java:214)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
11-05 11:56:14.171: E/AndroidRuntime(7805): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
11-05 11:56:14.171: E/AndroidRuntime(7805): at com.example.numero.JSONParser.makeHttpRequest(JSONParser.java:63)
11-05 11:56:14.171: E/AndroidRuntime(7805): at com.example.numero.FirstResult$GetProductDetails$1.run(FirstResult.java:105)
11-05 11:56:14.171: E/AndroidRuntime(7805): at android.os.Handler.handleCallback(Handler.java:725)
11-05 11:56:14.171: E/AndroidRuntime(7805): at android.os.Handler.dispatchMessage(Handler.java:92)
11-05 11:56:14.171: E/AndroidRuntime(7805): at android.os.Looper.loop(Looper.java:137)
11-05 11:56:14.171: E/AndroidRuntime(7805): at android.app.ActivityThread.main(ActivityThread.java:5041)
11-05 11:56:14.171: E/AndroidRuntime(7805): at java.lang.reflect.Method.invokeNative(Native Method)
11-05 11:56:14.171: E/AndroidRuntime(7805): at java.lang.reflect.Method.invoke(Method.java:511)
11-05 11:56:14.171: E/AndroidRuntime(7805): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
11-05 11:56:14.171: E/AndroidRuntime(7805): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
11-05 11:56:14.171: E/AndroidRuntime(7805): at dalvik.system.NativeStart.main(Native Method)
11-05 11:56:25.961: E/Trace(7893): error opening trace file: No such file or directory (2)
答案 0 :(得分：1)
您需要发布问题的堆栈跟踪。您将在logcat视图中找到它。另外，在旁注上：
runOnUiThread（new Runnable（）{ public void run（）{
这在这个地方根本没有任何意义，因为你基本上运行一个后台线程，然后你同步它并在主线程上运行它。这取决于您的设置，因为Android不允许在主/ UI线程上进行网络操作，因此无法正常工作。
添加LogCat后编辑：
这正是我提到的。 Android不允许您在UI线程上运行网络流量。从runOnBackground中删除runOnUiThread的东西。 现在要设置数据，你可以两件事中的两件：
添加设置textView的runOnUiThread部分。类似的东西：
runOnUiThread(new Runnable() {
public void run() {
TextView tv = findViewById...
tv.setText(...
}
}
返回您需要的对象。这实际上是AsyncTask的工作原理： 在你的AsyncTask的runOnBackground中，你可以这样做：
return product.getString(TAG_DESCRIPTION)
然后，在onPostExecute中，您将获得该String并将其设置为TextView。
答案 1 :(得分：1)
runOnUiThread(new Runnable() {
@Override
public void run()
{
// TODO Auto-generated method stub
try {
txt3.setText(product.getString(TAG_DESCRIPTION));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}else{
// product with pid not found
}
在
之后添加此行/ get first product object from JSON Array
JSONObject product = productObj.getJSONObject(0);
// product with this pid found
// Edit Text
txtName = (TextView) findViewById(R.id.textView3);
将解决问题