java - Activity 已泄漏窗口 com.android.internal.policy.impl.PhoneWindows$DecorView{42d9a800

Question

我正在编写一个从数据库获取数据的应用程序，但我收到此错误:

02-10 11:37:08.779  19458-19458/com.familiestvw.whatson E/WindowManager﹕ Activity com.familiestvw.whatson.AllVenuesActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{42d9a800 V.E..... R......D 0,0-1026,288} that was originally added here
android.view.WindowLeaked: Activity com.familiestvw.whatson.AllVenuesActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{42d9a800 V.E..... R......D 0,0-1026,288} that was originally added here
        at android.view.ViewRootImpl.<init>(ViewRootImpl.java:450)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:258)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:73)
        at android.app.Dialog.show(Dialog.java:287)
        at com.familiestvw.whatson.AllVenuesActivity$LoadAllVenues.onPreExecute(AllVenuesActivity.java:74)
        at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
        at android.os.AsyncTask.execute(AsyncTask.java:534)
        at com.familiestvw.whatson.AllVenuesActivity.onCreate(AllVenuesActivity.java:53)
        at android.app.Activity.performCreate(Activity.java:5372)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
        at android.app.ActivityThread.access$700(ActivityThread.java:159)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5419)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
        at dalvik.system.NativeStart.main(Native Method)

这是我的 Java 代码，很抱歉它的整个 Activity ，但我真的不知道错误发生在哪里，甚至不知道它是什么，我对 android 有点陌生:

package com.familiestvw.whatson;


public class AllVenuesActivity extends ListActivity {

// Progress Dialog
private ProgressDialog pDialog;

// Creating JSON Parser object
JSONParser jParser = new JSONParser();

ArrayList<HashMap<String, String>> venuesList;

// url to get all venues list
private static String url_all_venues = "http://10.0.2.2/android_connect/get_all_venues.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_VENUES = "venues";
private static final String TAG_VENUE_ID = "Venue_ID";
private static final String TAG_VENUE_NAME = "Venue_Name";

// venues JSONArray
JSONArray venues = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.all_venues);

    // Hashmap for ListView
    venuesList = new ArrayList<HashMap<String, String>>();

    // Loading venues in Background Thread
    new LoadAllVenues().execute();

    // Get listview
    ListView lv = getListView();
    }

/**
 * Background Async Task to Load all venues by making HTTP Request
 * */
class LoadAllVenues extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AllVenuesActivity.this);
        pDialog.setMessage("Loading venues. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All venues from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_all_venues, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("All Venues: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // venues found
                // Getting Array of Venues
                venues = json.getJSONArray(TAG_VENUES);

                // looping through All Venues
                for (int i = 0; i < venues.length(); i++) {
                    JSONObject c = venues.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_VENUE_ID);
                    String name = c.getString(TAG_VENUE_NAME);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_VENUE_ID, id);
                    map.put(TAG_VENUE_NAME, name);

                    // adding HashList to ArrayList
                    venuesList.add(map);
                }
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after getting all products
        pDialog.dismiss();
        // updating UI from Background Thread
        runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */
                ListAdapter adapter = new SimpleAdapter(
                        AllVenuesActivity.this, venuesList,
                        R.layout.list_item, new String[] { TAG_VENUE_ID,
                        TAG_VENUE_NAME},
                        new int[] { R.id.Venue_ID, R.id.Venue_Name });
                // updating listview
                setListAdapter(adapter);
            }
        });

    }

 }
}

有什么想法吗？？

Answer 1

当您试图关闭任何不再创建或不存在的对话框时，通常会发生这种情况。

可能的原因是

• 您的 Activity 已不存在，但您的任务仍在运行并试图关闭对话框。

• 您的应用在 doInBackgrond 中的某处崩溃。

检查 yopur JsonObject "c"的值，最好为 JsonObject 添加 null 检查或代码中可能出现 NullPointerException 的任何地方(此处为 doInbackground)。

onPostExcute 在主/UI 线程中运行，而不是在后台线程中运行。

编辑:

用这个替换你的 doInBackground 代码并确保你没有在任务运行之间切换 Activity :

protected String doInBackground(String... args) {
    // Building Parameters
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    // getting JSON string from URL
    JSONObject json = jParser.makeHttpRequest(url_all_venues, "GET", params);

    if(json!=null){
    // Check your log cat for JSON reponse
        Log.d("All Venues: ", json.toString());
        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
            // venues found
            // Getting Array of Venues
                venues = json.getJSONArray(TAG_VENUES);
                // looping through All Venues
                if(venues !=null){
                    for (int i = 0; i < venues.length(); i++) {
                        JSONObject c = venues.getJSONObject(i);
                        // Storing each json item in variable
                        if(c!=null){
                            String id = c.getString(TAG_VENUE_ID);
                            String name = c.getString(TAG_VENUE_NAME);
                        }
                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();
                        // adding each child node to HashMap key => value
                        map.put(TAG_VENUE_ID, id);
                        map.put(TAG_VENUE_NAME, name);
                         // adding HashList to ArrayList
                        venuesList.add(map);
                    }   
                }
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
    return null;
}