我有一个片段中的项目列表视图。当我点击其中一个项目时，它将打开另一个活动并显示该项目的详细信息。但是当加载进度条时，整个应用程序崩溃了。
EditProductActivity.java
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
JSONParser2 jsonParser2 = new JSONParser2();
// single product url
private static final String url_product_detials = "http://gemini888.tk/android_connect/get_product_details.php";
// url to update product
private static final String url_update_product = "http://gemini888.tk/android_connect/update_product.php";
// url to delete product
private static final String url_delete_product = "http://gemini888.tk/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 = jsonParser2.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 = (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 = jsonParser2.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(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 = jsonParser2.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();
}
}
}
刚刚做了一个正确的对齐
logcat：
04-22 05:41:18.881: D/All Products:(1262): {"success":1,"products": [{"created_at":"2015-04-15 21:52:09","pid":"1","updated_at":"0000-00-00 00:00:00","price":"1111.00","description":"good","name":"iphone "},{"created_at":"2015-04-18 02:41:49","pid":"13","updated_at":"0000-00-00 00:00:00","price":"60.00","description":"cheapo","name":"Samsung "},{"created_at":"2015-04-18 03:26:40","pid":"14","updated_at":"0000-00-00 00:00:00","price":"1000.00","description":"bad\n","name":"xiaomi"},{"created_at":"2015-04-21 05:56:55","pid":"15","updated_at":"0000-00-00 00:00:00","price":"500.00","description":"new","name":"Acer "},{"created_at":"2015-04-22 02:58:09","pid":"16","updated_at":"0000-00-00 00:00:00","price":"500.00","description":"??\n\n","name":"??"}]}
04-22 05:41:35.551: D/dalvikvm(1262): GC_FOR_ALLOC freed 253K, 9% free 3667K/3992K, paused 383ms, total 393ms
04-22 05:41:39.991: D/AndroidRuntime(1262): Shutting down VM
04-22 05:41:39.991: W/dalvikvm(1262): threadid=1: thread exiting with uncaught exception (group=0xb2a54ba8)
04-22 05:41:40.211: E/AndroidRuntime(1262): FATAL EXCEPTION: main
04-22 05:41:40.211: E/AndroidRuntime(1262): Process: mygp.gptrade, PID: 1262
04-22 05:41:40.211: E/AndroidRuntime(1262): android.os.NetworkOnMainThreadException
04-22 05:41:40.211: E/AndroidRuntime(1262): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
04-22 05:41:40.211: E/AndroidRuntime(1262): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
04-22 05:41:40.211: E/AndroidRuntime(1262): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
04-22 05:41:40.211: E/AndroidRuntime(1262): at java.net.InetAddress.getAllByName(InetAddress.java:214)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
04-22 05:41:40.211: E/AndroidRuntime(1262): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
04-22 05:41:40.211: E/AndroidRuntime(1262): at mygp.gptrade.JSONParser2.makeHttpRequest(JSONParser2.java:62)
04-22 05:41:40.211: E/AndroidRuntime(1262): at mygp.gptrade.EditProductActivity$GetProductDetails$1.run(EditProductActivity.java:131)
04-22 05:41:40.211: E/AndroidRuntime(1262): at android.os.Handler.handleCallback(Handler.java:733)
04-22 05:41:40.211: E/AndroidRuntime(1262): at android.os.Handler.dispatchMessage(Handler.java:95)
04-22 05:41:40.211: E/AndroidRuntime(1262): at android.os.Looper.loop(Looper.java:136)
04-22 05:41:40.211: E/AndroidRuntime(1262): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-22 05:41:40.211: E/AndroidRuntime(1262): at java.lang.reflect.Method.invokeNative(Native Method)
04-22 05:41:40.211: E/AndroidRuntime(1262): at java.lang.reflect.Method.invoke(Method.java:515)
04-22 05:41:40.211: E/AndroidRuntime(1262): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-22 05:41:40.211: E/AndroidRuntime(1262): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-22 05:41:40.211: E/AndroidRuntime(1262): at dalvik.system.NativeStart.main(Native Method)
04-22 05:41:47.031: I/Process(1262): Sending signal. PID: 1262 SIG: 9
答案 0 :(得分：1)
为什么你在runOnUiThread的{{1}}方法中执行doInBackground。该方法具体用于从主UI线程执行长时间运行操作。如果您想更新用户界面，请在GetProductDetails
进行以下更改
onPostExecute答案 1 :(得分：0)
onCreate 中添加了此代码
if (android.os.Build.VERSION.SDK_INT > 9)
{
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}