当我运行我的Android应用程序时，我遇到了android.os.NetworkOnMainThreadException错误。我还在清单文件中添加了 INTERNET 权限，但它仍然显示此错误。请帮助建议该怎么做。谢谢。
This is my logcat
03-06 11:40:55.721: W/dalvikvm(2142): threadid=1: thread exiting with uncaught exception (group=0x40014760)
03-06 11:40:55.740: E/AndroidRuntime(2142): FATAL EXCEPTION: main
03-06 11:40:55.740: E/AndroidRuntime(2142): android.os.NetworkOnMainThreadException
03-06 11:40:55.740: E/AndroidRuntime(2142): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1077)
03-06 11:40:55.740: E/AndroidRuntime(2142): at dalvik.system.BlockGuard$WrappedNetworkSystem.connect(BlockGuard.java:368)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:208)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:431)
03-06 11:40:55.740: E/AndroidRuntime(2142): at java.net.Socket.connect(Socket.java:901)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:143)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
03-06 11:40:55.740: E/AndroidRuntime(2142): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
03-06 11:40:55.740: E/AndroidRuntime(2142): at com.example.testexternaldatabase.JSONParser.makeHttpRequest(JSONParser.java:62)
03-06 11:40:55.740: E/AndroidRuntime(2142): at com.example.testexternaldatabase.EditTicketActivity$GetProductDetails$1.run(EditTicketActivity.java:135)
03-06 11:40:55.740: E/AndroidRuntime(2142): at android.os.Handler.handleCallback(Handler.java:587)
03-06 11:40:55.740: E/AndroidRuntime(2142): at android.os.Handler.dispatchMessage(Handler.java:92)
03-06 11:40:55.740: E/AndroidRuntime(2142): at android.os.Looper.loop(Looper.java:132)
03-06 11:40:55.740: E/AndroidRuntime(2142): at android.app.ActivityThread.main(ActivityThread.java:4025)
03-06 11:40:55.740: E/AndroidRuntime(2142): at java.lang.reflect.Method.invokeNative(Native Method)
03-06 11:40:55.740: E/AndroidRuntime(2142): at java.lang.reflect.Method.invoke(Method.java:491)
03-06 11:40:55.740: E/AndroidRuntime(2142): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
03-06 11:40:55.740: E/AndroidRuntime(2142): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-06 11:40:55.740: E/AndroidRuntime(2142): at dalvik.system.NativeStart.main(Native Method)This is my get_message_details.php file. This file is to accept input as a JSON Array and the messages table will be updated.
<?php
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
$_GET["pid"] = "1";
// check for post data
if (isset($_GET["pid"])) {
$message_id = $_GET['pid'];
// get a message from messages table
$result = mysql_query("SELECT *FROM messages WHERE message_id = '".$message_id."'");
if (!empty($result)) {
// check for empty result
if (mysql_num_rows($result) > 0) {
$result = mysql_fetch_array($result);
$message = array();
$message["message_id"] = $result["message_id"];
$message["subject"] = $result["subject"];
$message["type"] = $result["type"];
$message["description"] = $result["description"];
$response["success"] = 1;
// user node
$response["message"] = array();
array_push($response["message"], $message);
// echoing JSON response
echo json_encode($response);
} else {
// no message found
$response["success"] = 0;
$response["message"] = "No message found";
// echo no users JSON
echo json_encode($response);
}
} else {
// no message found
$response["success"] = 0;
$response["message"] = "No message found";
// echo no users JSON
echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
// echoing JSON response
echo json_encode($response);
}
?>
This is my EditTicketActivity.java class.package com.example.testexternaldatabase;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.*;
public class EditTicketActivity extends Activity {
EditText txtSubject;
EditText txtType;
EditText txtDesc;
Button btnSave;
Button btnDelete;
String pid;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
static GetIPAddress getIPaddress = new GetIPAddress();
// single product url
private static String url_product_details = getIPaddress.getIP()+"get_message_details.php";;
// url to update product
private static String url_update_product = getIPaddress.getIP()+"update_message.php";
// url to delete product
private static String url_delete_product = getIPaddress.getIP()+"delete_message.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCT = "message";
private static final String TAG_PID = "message_id";
private static final String TAG_NAME = "subject";
private static final String TAG_PRICE = "type";
private static final String TAG_DESCRIPTION = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_ticket);
//url_product_details = getIPaddress.getIP()+"get_message_details.php";
//url_update_product = getIPaddress.getIP()+"update_message.php";
//url_delete_product = getIPaddress.getIP()+"delete_message.php";
// save button
btnSave = (Button)findViewById(R.id.editticket_save);
btnDelete = (Button)findViewById(R.id.editticket_delete);
// getting product details from intent
Intent i = getIntent();
// getting product id (pid) from intent
pid = i.getStringExtra(TAG_PID);
// Getting complete product details in background thread
new GetProductDetails().execute();
// save button click event
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// starting background task to update product
new SaveProductDetails().execute();
}
});
// Delete button click event
btnDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// deleting product in background thread
new DeleteProduct().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(EditTicketActivity.this);
pDialog.setMessage("Loading Tickets. 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_details, "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 messageObj = json
.getJSONArray(TAG_PRODUCT); // JSON Array
// get first product object from JSON Array
JSONObject message = messageObj.getJSONObject(0);
// product with this pid found
// Edit Text
txtSubject = (EditText) findViewById(R.id.editticket_subject);
txtType = (EditText) findViewById(R.id.editticket_type);
txtDesc = (EditText) findViewById(R.id.editticket_description);
// display product data in EditText
txtSubject.setText(message.getString(TAG_NAME));
txtType.setText(message.getString(TAG_PRICE));
txtDesc.setText(message.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();
}
}
/**
* Background Async Task to Save product Details
* */
class SaveProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(EditTicketActivity.this);
pDialog.setMessage("Saving product ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Saving product
* */
protected String doInBackground(String... args) {
// getting updated data from EditTexts
String subject = txtSubject.getText().toString();
String type = txtType.getText().toString();
String description = txtDesc.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair(TAG_PID, pid));
params.add(new BasicNameValuePair(TAG_NAME, subject));
params.add(new BasicNameValuePair(TAG_PRICE, type));
params.add(new BasicNameValuePair(TAG_DESCRIPTION, description));
// sending modified data through http request
// Notice that update product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_update_product,
"POST", params);
// check json success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully updated
Intent i = getIntent();
// send result code 100 to notify about product update
setResult(100, i);
finish();
} else {
// failed to update product
}
} 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 product uupdated
pDialog.dismiss();
}
}
/*****************************************************************
* Background Async Task to Delete Product
* */
class DeleteProduct extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(EditTicketActivity.this);
pDialog.setMessage("Deleting Product...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Deleting product
* */
protected String doInBackground(String... args) {
// 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
JSONObject json = jsonParser.makeHttpRequest(
url_delete_product, "POST", params);
// check your log for json response
Log.d("Delete Product", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// product successfully deleted
// notify previous activity by sending code 100
Intent i = getIntent();
// send result code 100 to notify about product deletion
setResult(100, i);
finish();
}
} 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 product deleted
pDialog.dismiss();
}
}
}在这里做错了什么，我该如何解决它？:)谢谢！！
不应Asynctask doInBackground()方法中使用 UI 元素。将所有 UI 更新代码移动到AsyncTask onPostExecute()方法
您可以参考的示例
AsyncTask 安卓示例