如何修复:致命异常:main android.os.NetworkOnMainThreadException [英] how to fix: FATAL EXCEPTION:main android.os.NetworkOnMainThreadException
本文介绍了如何修复:致命异常:main android.os.NetworkOnMainThreadException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有problems在android 18版上运行我的代码.我使用了AsyncTask但仍然出现错误，请帮助.我是编程的菜鸟，所以请原谅我的错误
i am having probelms running my code on android version 18. i have used the AsyncTask but still getting an error, plz help. I am a noob to programming so please excuse my errors
package com.example.androidhive;
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.Button;
import android.widget.EditText;
public class EditProductActivity extends Activity {
EditText txtName;
EditText txtPrice;
EditText txtDesc;
EditText txtCreatedAt;
Button btnSave;
Button btnDelete;
String pid;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// single product url
private static final String url_product_detials = "http://10.0.2.2/android_connect/get_product_details.php";
// url to update product
private static final String url_update_product = "http://10.0.2.2/android_connect/update_product.php";
// url to delete product
private static final String url_delete_product = "http://10.0.2.2/android_connect/delete_product.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_NAME = "name";
private static final String TAG_PRICE = "price";
private static final String TAG_DESCRIPTION = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_product);
// save button
btnSave = (Button) findViewById(R.id.btnSave);
btnDelete = (Button) findViewById(R.id.btnDelete);
// 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(EditProductActivity.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);
setContentView(R.layout.edit_product);
// product with this pid found
// Edit Text
txtName = (EditText) findViewById(R.id.inputName);
txtPrice = (EditText) findViewById(R.id.inputPrice);
txtDesc = (EditText) findViewById(R.id.inputDesc);
// display product data in EditText
txtName.setText(product.getString(TAG_NAME));
txtPrice.setText(product.getString(TAG_PRICE));
txtDesc.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();
}
}
/**
* 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(EditProductActivity.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 name = txtName.getText().toString();
String price = txtPrice.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, name));
params.add(new BasicNameValuePair(TAG_PRICE, price));
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 updated
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(EditProductActivity.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();
}
}
}
我得到的错误是:
10-27 17:01:52.858: E/AndroidRuntime(2001): FATAL EXCEPTION: main
10-27 17:01:52.858: E/AndroidRuntime(2001): android.os.NetworkOnMainThreadException
10-27 17:01:52.858: E/AndroidRuntime(2001): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
10-27 17:01:52.858: E/AndroidRuntime(2001): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
10-27 17:01:52.858: E/AndroidRuntime(2001): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
10-27 17:01:52.858: E/AndroidRuntime(2001): at libcore.io.IoBridge.connect(IoBridge.java:112)
10-27 17:01:52.858: E/AndroidRuntime(2001): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
10-27 17:01:52.858: E/AndroidRuntime(2001): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
10-27 17:01:52.858: E/AndroidRuntime(2001): at java.net.Socket.connect(Socket.java:842)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
10-27 17:01:52.858: E/AndroidRuntime(2001): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
10-27 17:01:52.858: E/AndroidRuntime(2001): at com.example.androidhive.JSONParser.makeHttpRequest(JSONParser.java:62)
10-27 17:01:52.858: E/AndroidRuntime(2001): at com.example.androidhive.EditProductActivity$GetProductDetails$1.run(EditProductActivity.java:137)
10-27 17:01:52.858: E/AndroidRuntime(2001): at android.os.Handler.handleCallback(Handler.java:730)
10-27 17:01:52.858: E/AndroidRuntime(2001): at android.os.Handler.dispatchMessage(Handler.java:92)
10-27 17:01:52.858: E/AndroidRuntime(2001): at android.os.Looper.loop(Looper.java:137)
10-27 17:01:52.858: E/AndroidRuntime(2001): at android.app.ActivityThread.main(ActivityThread.java:5103)
10-27 17:01:52.858: E/AndroidRuntime(2001): at java.lang.reflect.Method.invokeNative(Native Method)
10-27 17:01:52.858: E/AndroidRuntime(2001): at java.lang.reflect.Method.invoke(Method.java:525)
10-27 17:01:52.858: E/AndroidRuntime(2001): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
10-27 17:01:52.858: E/AndroidRuntime(2001): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-27 17:01:52.858: E/AndroidRuntime(2001): at dalvik.system.NativeStart.main(Native Method)
布局xml布局如下所示:
and the layout xml layout looks like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<!-- Name Label -->
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="10dip"
android:paddingRight="10dip"
android:paddingTop="10dip"
android:text="@string/Product_Name2"
android:textSize="17sp" />
<!-- Input Name -->
<EditText android:id="@+id/inputName"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/inputName2"
android:layout_margin="5dip"
android:layout_marginBottom="15dip"
android:singleLine="true"/>
<!-- Price Label -->
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="10dip"
android:paddingRight="10dip"
android:paddingTop="10dip"
android:text="@string/Price2"
android:textSize="17sp" />
<!-- Input Price -->
<EditText android:id="@+id/inputPrice"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:layout_marginBottom="15dip"
android:singleLine="true"
android:inputType="numberDecimal"/>
<!-- Description Label -->
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="10dip"
android:paddingRight="10dip"
android:paddingTop="10dip"
android:text="@string/Description2"
android:textSize="17sp" />
<!-- Input description -->
<EditText android:id="@+id/inputDesc"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/inputDesc2"
android:layout_margin="5dip"
android:layout_marginBottom="15dip"
android:lines="4"
android:gravity="top"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<!-- Button Create Product -->
<Button
android:id="@+id/btnSave"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/Save_Changes" />
<!-- Button Create Product -->
<Button
android:id="@+id/btnDelete"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/Delete" />
</LinearLayout>
</LinearLayout>
推荐答案
在 GetProductDetails 类中只使用 try catch.删除 runOnUiThread() .
In the GetProductDetails class use only try catch. remove the runOnUiThread() .
这篇关于如何修复:致命异常:main android.os.NetworkOnMainThreadException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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