问题
i have a listView of item in a fragment. when i click one of the item, it will open another activity and show the details of the item. but when the progress bar is loading then the whole app crashed.
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();
}
}
}
just made a proper alignment
the 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
回答1:
Why are you doing runOnUiThread in the doInBackground method of GetProductDetails. The method is specifically there to do long running operation off the main UI thread. If you want to update the UI then do it in onPostExecute
Make the following change
/**
* Background Async Task to Get complete product details
*/
class GetProductDetails extends AsyncTask<String, String, String> {
JSONObject json = null;
/**
* 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) {
// 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
json = jsonParser2.makeHttpRequest(
url_product_detials, "GET", params);
// check your log for json response
Log.d("Single Product Details", json.toString());
} 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();
if (json != null) {
// 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
}
}
}
}
回答2:
i solved my problem.
i add this code in onCreate
if (android.os.Build.VERSION.SDK_INT > 9)
{
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
来源：https://stackoverflow.com/questions/29793846/onitemclicked-from-fragment-to-activity