Question

我试图理解内存泄漏的概念。我尝试了这个代码并尝试了几种从相关帖子中找到的方法，但我无法解决问题。需要帮助来了解此代码中发生内存泄漏的位置。我的申请只有2项活动

//第一项活动

package com.pace.mat;

import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MATDemoActivity extends Activity implements OnClickListener {

    private Dialog dialog1;
    private Button btnSubmit;
    private Context myClassContext;
    private ImageView RedImage,BlueImage,Yellow,Orange,Green;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myClassContext = this;

        RedImage = (ImageView) findViewById(R.id.Red);
        BlueImage = (ImageView) findViewById(R.id.Blue);
        Yellow = (ImageView) findViewById(R.id.Yellow);
        Orange = (ImageView) findViewById(R.id.Orange);
        Green = (ImageView) findViewById(R.id.Green);

       RedImage.setImageResource(R.drawable.red);
       BlueImage.setImageResource(R.drawable.blue);
       Yellow.setImageResource(R.drawable.yellow);
       Orange.setImageResource(R.drawable.orange);
       Green.setImageResource(R.drawable.green);

        btnSubmit = (Button)findViewById(R.id.btnSubmitAtFirst);
        btnSubmit.setOnClickListener(this);

    }

    public void onClick(View arg0) {
        // TODO Auto-generated method stub
        if(arg0 == (View)btnSubmit)
        {
            dialog1=new Dialog(myClassContext); 
            Window window = dialog1.getWindow(); 
            window.setBackgroundDrawableResource(android.R.color.transparent); 
            window.requestFeature(window.FEATURE_NO_TITLE);                     
            dialog1.setContentView(R.layout.progress_indicator); 
            dialog1.show();     

            // Doing a network intensive task

            if(dialog1 !=null)
            {
                dialog1 = null;
                myClassContext =  null;
                window = null;
            }

            Intent i = new Intent(MATDemoActivity.this,SecondActivity.class);
            startActivity(i);
        }
    }

    @Override
    public void onStop() {    
        super.onStop();  
        myClassContext =  null;
        dialog1 = null;
        RedImage = null;
        BlueImage = null;
        Yellow = null;
        Orange = null;

        Green=null;
        this.finish();   
    }       

    @Override
    public void onPause() {
        super.onPause();
         myClassContext =  null;
            dialog1 = null;
            RedImage = null;
            BlueImage = null;
            Yellow = null;

            Orange = null;
            Green=null;
         this.finish(); 
    }           

    @Override
    public void onDestroy() {
        super.onDestroy();
         myClassContext =  null;
            dialog1 = null;
            RedImage = null;
            BlueImage = null;

            Yellow = null;
            Orange = null;
            Green=null;
        this.finish();
    }

}

//第二项活动

package com.pace.mat;

import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class SecondActivity extends Activity implements OnClickListener {

    private Dialog dialog1;
    private Button btnSubmit;
    private Context myClassContext1;
    private ImageView RedImage,BlueImage,Yellow,Orange,Green;

     /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.secondactivity);

        myClassContext1 = this;

        RedImage = (ImageView) findViewById(R.id.Red);
        BlueImage = (ImageView) findViewById(R.id.Blue);
        Yellow = (ImageView) findViewById(R.id.Yellow);
        Orange = (ImageView) findViewById(R.id.Orange);
        Green = (ImageView) findViewById(R.id.Green);

       RedImage.setImageResource(R.drawable.red);
       BlueImage.setImageResource(R.drawable.blue);
       Yellow.setImageResource(R.drawable.yellow);
       Orange.setImageResource(R.drawable.orange);
       Green.setImageResource(R.drawable.green);

        btnSubmit = (Button)findViewById(R.id.btnSubmitAtFirst);
        btnSubmit.setOnClickListener(this);
    }

    public void onClick(View v) {
        // TODO Auto-generated method stub
        if(v == (View)btnSubmit)
        {
            dialog1=new Dialog(myClassContext1); 
            Window window = dialog1.getWindow(); 
            window.setBackgroundDrawableResource(android.R.color.transparent); 
            window.requestFeature(window.FEATURE_NO_TITLE);                     
            dialog1.setContentView(R.layout.progress_indicator); 
            dialog1.show();     

            // Uploading an Image to network 

            if(dialog1 !=null)
            {
                dialog1 = null;
                myClassContext1 =  null;
                window = null;
            }

            Intent i = new Intent(this,MATDemoActivity.class);
            startActivity(i);
        }
    }

    @Override
    public void onStop() {    
        super.onStop();  

        this.finish();   
    }       

    @Override
    public void onPause() {
        super.onPause();

         this.finish(); 
    }           

    @Override
    public void onDestroy() {
        super.onDestroy();
         myClassContext1 =  null;
            dialog1 = null;
            RedImage = null;
            BlueImage = null;

            Yellow = null;
            Orange = null;
            Green=null;
        this.finish();
    }

}

//当我从第一次活动到第二次活动时记录CAT数据

05-17 12:12:43.323: E/WindowManager(2264): Activity com.pace.mat.SecondActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f63b88 that was originally added here
05-17 12:12:43.323: E/WindowManager(2264): android.view.WindowLeaked: Activity com.pace.mat.SecondActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f63b88 that was originally added here
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.ViewRoot.<init>(ViewRoot.java:247)
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.Window$LocalWindowManager.addView(Window.java:424)
05-17 12:12:43.323: E/WindowManager(2264):  at android.app.Dialog.show(Dialog.java:241)
05-17 12:12:43.323: E/WindowManager(2264):  at com.pace.mat.SecondActivity.onClick(SecondActivity.java:54)
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.View.performClick(View.java:2408)
05-17 12:12:43.323: E/WindowManager(2264):  at android.view.View$PerformClick.run(View.java:8816)
05-17 12:12:43.323: E/WindowManager(2264):  at android.os.Handler.handleCallback(Handler.java:587)
05-17 12:12:43.323: E/WindowManager(2264):  at android.os.Handler.dispatchMessage(Handler.java:92)
05-17 12:12:43.323: E/WindowManager(2264):  at android.os.Looper.loop(Looper.java:123)
05-17 12:12:43.323: E/WindowManager(2264):  at android.app.ActivityThread.main(ActivityThread.java:4627)
05-17 12:12:43.323: E/WindowManager(2264):  at java.lang.reflect.Method.invokeNative(Native Method)
05-17 12:12:43.323: E/WindowManager(2264):  at java.lang.reflect.Method.invoke(Method.java:521)
05-17 12:12:43.323: E/WindowManager(2264):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-17 12:12:43.323: E/WindowManager(2264):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-17 12:12:43.323: E/WindowManager(2264):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

您的代码似乎没有任何内存泄漏。并且大多数时候内存泄漏是由于保持对Context的长期引用。

这是Romain Guy的一篇好文章，它将帮助您详细了解内存泄漏。 check it out

希望它会有所帮助。

编辑：根据您更新了您的问题

看了你的日志后，似乎没有内存泄漏，它的窗口泄露异常。在完成活动之前关闭或关闭对话框。这将解决您的问题。

Answer 2

看起来你正在重复地呼叫另一个活动，就像你循环进入活动并切换它们一样。

MATDemoActivity来电

Intent i = new Intent(MATDemoActivity.this,SecondActivity.class); 
            startActivity(i);

然后从你呼叫的SecondActivity

Intent i = new Intent(this,MATDemoActivity.class);   
        startActivity(i);

您也在重新创建每个活动中的所有对象，而不是在两个活动之间共享它们。

尝试修复这些问题并查看是否有效。

Answer 3

从日志中，我认为问题的原因是您显示了一个对话框但没有将其关闭，然后您将对话框指定为null并启动另一个活动。

if(dialog1 !=null)
{
    dialog1 = null;
    myClassContext1 =  null;
    window = null;
}

因此活动将泄漏对话框（对话框是窗口）。无论如何，如果你不需要显示对话框，你应该将其解雇。

Android内存泄漏代码

3 个答案: