Android異常一、異步任務導致的窗口句柄泄漏問題(轉)

05-05 10:36:41.009: E/WindowManager(4243): Activity com.tao.MyActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405241b0 that was originally added here
05-05 10:36:41.009: E/WindowManager(4243): android.view.WindowLeaked: Activity com.tao.MyActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405241b0 that was originally added here
05-05 10:36:41.009: E/WindowManager(4243):     at android.view.ViewRoot.<init>(ViewRoot.java:265)
05-05 10:36:41.009: E/WindowManager(4243):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
05-05 10:36:41.009: E/WindowManager(4243):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
05-05 10:36:41.009: E/WindowManager(4243):     at android.view.Window$LocalWindowManager.addView(Window.java:424)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.Dialog.show(Dialog.java:241)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ProgressDialog.show(ProgressDialog.java:107)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ProgressDialog.show(ProgressDialog.java:95)
05-05 10:36:41.009: E/WindowManager(4243):     at com.unifable.activity.MySecretaryActivity.onCreate(MySecretaryActivity.java:50)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
05-05 10:36:41.009: E/WindowManager(4243):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-05 10:36:41.009: E/WindowManager(4243):     at android.os.Looper.loop(Looper.java:130)
05-05 10:36:41.009: E/WindowManager(4243):     at android.app.ActivityThread.main(ActivityThread.java:3683)
05-05 10:36:41.009: E/WindowManager(4243):     at java.lang.reflect.Method.invokeNative(Native Method)
05-05 10:36:41.009: E/WindowManager(4243):     at java.lang.reflect.Method.invoke(Method.java:507)
05-05 10:36:41.009: E/WindowManager(4243):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:906)
05-05 10:36:41.009: E/WindowManager(4243):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:664)
05-05 10:36:41.009: E/WindowManager(4243):     at dalvik.system.NativeStart.main(Native Method)

這是在做一個項目的時候遇到的問題：在第一界面的Activity中，為了避免程序假死帶來的糟糕的用戶體驗，采用異步任務AsyncTask來訪問網絡，與服務器進行交互，並用
ProgressDialog控件來告知用戶當前的程序進度。

在網上查了下別人的資料。才終於明白了原因。
上面的異常的意思是：存在窗口句柄的泄漏，即未能及時的銷毀某個PhoneWindow.

為什么會出現這樣的情況，因為，在異步任務里面已經發生了嚴重的錯誤，而導致Activity的強制關閉。Activity強制關閉了，可是ProgressDialog並沒有dismiss()掉，所以出現了
窗口句柄的泄漏。 而且，更嚴重的是，這個異常會覆蓋我們在AsyncTask里面發生的真正異常，這往往會誤導我們，把過多的精力放在查找所謂的內存泄漏的上面，而不是查找AsyncTask
中出現的錯誤。

參照別人的解決方法：
本解決方法並不能真正的解決問題，但是在一定程度上可以將真正導致錯誤的異常信息顯露出來。即重寫Activity的onDestory()方法，在該方法中調用dismiss()來解除對ProgressDialog
的引用。

　 本文轉自http://blog.csdn.net/lonelyroamer/article/details/7536962