java - 泄漏了最初在此处添加的窗口 com.android.internal.policy.impl.PhoneWindow$DecorView{b5596468 V.E..... R.....ID 0,0-456,144}

Question

当我尝试从当前 Activity 开始新 Activity 时出现泄漏错误，并且我认为当前 Activity 在开始新 Activity 之前已正确关闭，所以您能帮忙指出我的代码哪里出了问题吗？

package com.example.mediastore;

import java.util.ArrayList;
import java.util.List;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import com.example.mediastore.JSONParser;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.InputFilter.LengthFilter;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class LoginActivity extends Activity {

    Button login;
    EditText inputusername;
    EditText inputpassword;
    private static String url_users = "http://10.0.2.2/mediastore/android/usersLogin.php";
    private ProgressDialog pDialog;
    JSONParser jsonParser = new JSONParser();
    private static final String TAG_SUCCESS = "success";
    boolean startActivity;

    @Override
    public void finish()
    {
        if (pDialog != null && pDialog.isShowing())
        {
             pDialog.dismiss();
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {

        this.requestWindowFeature(Window.FEATURE_NO_TITLE);

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        login = (Button) findViewById(R.id.loginbtn);
        inputusername = (EditText) findViewById(R.id.username);
        inputpassword = (EditText) findViewById(R.id.password);



        login.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

               if(v == login) {
                    login.setBackgroundDrawable(getResources().getDrawable(R.drawable.button2));
               }
               String u = inputusername.getText().toString();
               String p = inputpassword.getText().toString();

                if(u.equals("")||p.equals(""))
                    Toast.makeText(getApplicationContext(), "Please fill these two fields", Toast.LENGTH_SHORT).show();
                else{
                    new userLogin().execute();
                }
            }
        });
    }

    class userLogin extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(LoginActivity.this);
            pDialog.setMessage("Logging user..");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }


        /**
         * Creating product
         * */
        @SuppressLint("ShowToast")
        protected String doInBackground(String... args) {
            String username = inputusername.getText().toString();
            String password = inputpassword.getText().toString();

            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("username", username));
            params.add(new BasicNameValuePair("password", password));

            // getting JSON Object
            // Note that create product url accepts POST method
            JSONObject json = jsonParser.makeHttpRequest(url_users,
                    "POST", params);

            // check log cat for response
            Log.d("Login Response", json.toString());

            // check for success tag
            try {
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // successfully created product
                    startActivity = true;

                    // closing this screen
                    finish();
                } else {
                    // failed to create 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 done

            pDialog.dismiss();

            if(startActivity){  
                Intent i = new Intent(getApplicationContext(), UserViewActivity.class);
                startActivity(i);
            }

        }
    }

}

这是日志猫:

10-04 10:50:27.129: E/WindowManager(1629): Activity com.example.mediastore.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b5596468 V.E..... R.....ID 0,0-456,144} that was originally added here
10-04 10:50:27.129: E/WindowManager(1629): android.view.WindowLeaked: Activity com.example.mediastore.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b5596468 V.E..... R.....ID 0,0-456,144} that was originally added here
10-04 10:50:27.129: E/WindowManager(1629):  at android.view.ViewRootImpl.<init>(ViewRootImpl.java:354)
10-04 10:50:27.129: E/WindowManager(1629):  at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:216)
10-04 10:50:27.129: E/WindowManager(1629):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
10-04 10:50:27.129: E/WindowManager(1629):  at android.app.Dialog.show(Dialog.java:281)
10-04 10:50:27.129: E/WindowManager(1629):  at com.example.mediastore.LoginActivity$userLogin.onPreExecute(LoginActivity.java:93)
10-04 10:50:27.129: E/WindowManager(1629):  at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
10-04 10:50:27.129: E/WindowManager(1629):  at android.os.AsyncTask.execute(AsyncTask.java:534)
10-04 10:50:27.129: E/WindowManager(1629):  at com.example.mediastore.LoginActivity$1.onClick(LoginActivity.java:75)
10-04 10:50:27.129: E/WindowManager(1629):  at android.view.View.performClick(View.java:4202)
10-04 10:50:27.129: E/WindowManager(1629):  at android.view.View$PerformClick.run(View.java:17340)
10-04 10:50:27.129: E/WindowManager(1629):  at android.os.Handler.handleCallback(Handler.java:725)
10-04 10:50:27.129: E/WindowManager(1629):  at android.os.Handler.dispatchMessage(Handler.java:92)
10-04 10:50:27.129: E/WindowManager(1629):  at android.os.Looper.loop(Looper.java:137)
10-04 10:50:27.129: E/WindowManager(1629):  at android.app.ActivityThread.main(ActivityThread.java:5039)
10-04 10:50:27.129: E/WindowManager(1629):  at java.lang.reflect.Method.invokeNative(Native Method)
10-04 10:50:27.129: E/WindowManager(1629):  at java.lang.reflect.Method.invoke(Method.java:511)
10-04 10:50:27.129: E/WindowManager(1629):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
10-04 10:50:27.129: E/WindowManager(1629):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
10-04 10:50:27.129: E/WindowManager(1629):  at dalvik.system.NativeStart.main(Native Method)

新错误:

10-04 14:02:14.414: E/JSON Parser(1909): Error parsing data org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
10-04 14:02:14.434: W/dalvikvm(1909): threadid=13: thread exiting with uncaught exception (group=0xb4d01908)
10-04 14:02:14.494: E/AndroidRuntime(1909): FATAL EXCEPTION: AsyncTask #3
10-04 14:02:14.494: E/AndroidRuntime(1909): java.lang.RuntimeException: An error occured while executing doInBackground()
10-04 14:02:14.494: E/AndroidRuntime(1909):     at android.os.AsyncTask$3.done(AsyncTask.java:299)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.FutureTask.run(FutureTask.java:239)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.lang.Thread.run(Thread.java:856)
10-04 14:02:14.494: E/AndroidRuntime(1909): Caused by: java.lang.NullPointerException
10-04 14:02:14.494: E/AndroidRuntime(1909):     at com.example.mediastore.LoginActivity$userLogin.doInBackground(LoginActivity.java:123)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at com.example.mediastore.LoginActivity$userLogin.doInBackground(LoginActivity.java:1)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at android.os.AsyncTask$2.call(AsyncTask.java:287)
10-04 14:02:14.494: E/AndroidRuntime(1909):     at java.util.concurrent.FutureTask.run(FutureTask.java:234)
10-04 14:02:14.494: E/AndroidRuntime(1909):     ... 4 more
10-04 14:02:19.734: E/WindowManager(1909): Activity com.example.mediastore.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b55038e8 V.E..... R.....ID 0,0-456,144} that was originally added here
10-04 14:02:19.734: E/WindowManager(1909): android.view.WindowLeaked: Activity com.example.mediastore.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b55038e8 V.E..... R.....ID 0,0-456,144} that was originally added here
10-04 14:02:19.734: E/WindowManager(1909):  at android.view.ViewRootImpl.<init>(ViewRootImpl.java:354)
10-04 14:02:19.734: E/WindowManager(1909):  at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:216)
10-04 14:02:19.734: E/WindowManager(1909):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
10-04 14:02:19.734: E/WindowManager(1909):  at android.app.Dialog.show(Dialog.java:281)
10-04 14:02:19.734: E/WindowManager(1909):  at com.example.mediastore.LoginActivity$userLogin$1.run(LoginActivity.java:99)
10-04 14:02:19.734: E/WindowManager(1909):  at android.os.Handler.handleCallback(Handler.java:725)
10-04 14:02:19.734: E/WindowManager(1909):  at android.os.Handler.dispatchMessage(Handler.java:92)
10-04 14:02:19.734: E/WindowManager(1909):  at android.os.Looper.loop(Looper.java:137)
10-04 14:02:19.734: E/WindowManager(1909):  at android.app.ActivityThread.main(ActivityThread.java:5039)
10-04 14:02:19.734: E/WindowManager(1909):  at java.lang.reflect.Method.invokeNative(Native Method)
10-04 14:02:19.734: E/WindowManager(1909):  at java.lang.reflect.Method.invoke(Method.java:511)
10-04 14:02:19.734: E/WindowManager(1909):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
10-04 14:02:19.734: E/WindowManager(1909):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
10-04 14:02:19.734: E/WindowManager(1909):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

尝试将 finish() 仅放在 startActivity(i) 之后；在你的 onPostExecute 方法中。

我经历过调用 finish 也会删除全局声明的变量以及后台发生的许多其他事情。

编辑 1.

同时删除 super.onPreExecute();并将这段代码放在 onPreExecute 中:

    Handler h= new Handler();
    h.post(new Runnable() {
          @Override
          public void run() {
        pDialog = new ProgressDialog(LoginActivity.this);
        pDialog.setMessage("Logging user..");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
      }
    });

可能会有一两个拼写错误，所以不要复制/粘贴，而是自己在 Eclipse 中输入。