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更新时间：2023-01-23 21:54:13
你为什么要这么做 runOnUiThread 在 doInBackground GetProductDetails的方法。该方法是专门有做长期运行的操作关闭主UI线程。如果您想更新UI，然后做在 onPostExecute
请以下更改
/ **
*背景异步任务以获得完整的产品细节
* /
类GetProductDetails扩展的AsyncTask＆LT;字符串，字符串，字符串＆GT; {
JSONObject的JSON = NULL; / **
*启动后台线程显示进度对话框之前
* /
@覆盖
在preExecute保护无效（）{
super.on preExecute（）;
pDialog =新ProgressDialog（EditProductActivity.this）;
pDialog.setMessage（装载产品的详细信息，请稍候...）;
pDialog.setIndeterminate（假）;
pDialog.setCancelable（真）;
pDialog.show（）;
} / **
*获取产品的详细信息在后台线程
* /
保护字符串doInBackground（字符串... PARAMS）{ //检查成功标记
诠释成功;
尝试{
//大厦参数
清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
params.add（新BasicNameValuePair（PID，PID））; //通过HTTP请求获得产品的详细信息
//注意产品的详细信息URL会使用GET请求
JSON = jsonParser2.makeHtt prequest（
url_product_detials，GET，则params）; //检查你的日志，JSON响应
Log.d（单一产品详细信息，json.toString（））; }赶上（JSONException E）{
e.printStackTrace（）;
} 返回null;
} / **
*在完成后台任务之后辞退进度对话框
** /
保护无效onPostExecute（字符串FILE_URL）{
//关闭该对话框一旦得了所有细节
pDialog.dismiss（）; 如果（JSON！= NULL）{
// JSON的成功标签
成功= json.getInt（TAG_SUCCESS）;
如果（成功== 1）{
//成功接收产品的详细信息
JSONArray productObj = JSON
.getJSONArray（TAG_PRODUCT）; // JSON数组 //从JSON数组的第一个产品对象
的JSONObject产物= productObj.getJSONObject（0）; //与本产品的PID发现
//编辑文本
txtName的=（的EditText）findViewById（R.id.inputName）;
txtPrice =（EditText上）findViewById（R.id.inputPrice）;
txtDesc =（EditText上）findViewById（R.id.inputDesc）; //在显示的EditText产品数据
txtName.setText（product.getString（TAG_NAME））;
txtPrice.setText（product.getString（TAG_PRICE））;
txtDesc.setText（product.getString（TAG_DESCRIPTION））; }其他{
//产品具有pid未找到
}
} }
}
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
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
}
}
}
}