尽管使用了WeakReference，AlertDialog仍然泄漏

问题描述

我在处理程序中创建AlertDialog时遇到问题，因为它会导致内存泄漏或其他错误。

细节：

我有一个Activity，Thread和Handler与对活动的WeakReference。 在开始线程之前，我在活动类中创建ProgressDialog dialog 。 线程任务具有对MyHandler对象的引用。 当用户在我的活动中关闭dialog时，onCancelListener会调用线程的interrupt（）。 我的线程安全地完成了任务，并向主活动线程发送了消息DOWNLOAD_STATE.CANCELLED。 然后我在MyHandler中使用代码MyHandler

问题：

问题是，当用户在解除alert （取消线程）并在创建新的AlertDialog之前（在MyHandler类内部）按下后退按钮。 花了大约第二秒。 当用户此时不回压时，一切正常。

它在这里泄漏（在MyHandler类内部）： new AlertDialog.Builder(activity).setMessage("update cancelled").setPositiveButton("OK", null).show();

正常的情况是，当用户按下“后退”按钮时，活动被销毁（活动onBackKeyPressed的效果），但是为什么不停止AlertDialog并创建AlertDialog呢？

我的处理程序类：

static class MyHandler extends Handler {

    WeakReference<MainActivity> activityRef;
    MyHandler(MainActivity activity)
    {
        this.activityRef=new WeakReference<MainActivity>(activity);
    }

    @Override
    public void handleMessage(Message msg) {

        MainActivity activity=activityRef.get();
        if(activity==null)
            return;

        if (msg.arg1==DownloadTask.DOWNLOAD_STATE.FINISHED.ordinal())
        {
            activity.dialog.dismiss();
            Toast.makeText(activity, "updated", Toast.LENGTH_LONG).show();
        }

        else if( msg.arg1== DownloadTask.DOWNLOAD_STATE.CANCELLED.ordinal())
        {
            new AlertDialog.Builder(activity).setMessage("update cancelled").setPositiveButton("OK", null).show();
        }

        else if(msg.arg1==DownloadTask.DOWNLOAD_STATE.ERROR.ordinal())
        {

              activity.dialog.dismiss();
            new AlertDialog.Builder(activity).setMessage(activity.getString(R.string.no_connection_info)).setPositiveButton("OK", null).show();
        }

    }
}

内部线程的可运行状态：

if(Thread.interrupted()) 
        {
            Message msg=handler.obtainMessage();
            msg.arg1=DOWNLOAD_STATE.CANCELLED.ordinal();
            msg.arg2=counter;
            msg.obj=cities.length;
            handler.sendMessage(msg);

            return;
        }

错误堆栈跟踪1：

android.view.WindowLeaked: Activity com.mycompany.mooz.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@42723848 that was originally added here
        at android.view.ViewRootImpl.<init>(ViewRootImpl.java:403)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:311)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:224)
        at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:149)
        at android.view.Window$LocalWindowManager.addView(Window.java:554)
        at android.app.Dialog.show(Dialog.java:277)
        at android.support.v7.app.AlertDialog$Builder.show(AlertDialog.java:902)
        at com.mycompany.mooz.MainActivity$MyHandler.handleMessage(MainActivity.java:55)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4921)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
        at dalvik.system.NativeStart.main(Native Method)

错误堆栈跟踪2：

android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@427329e0 is not valid; is your activity running?
        at android.view.ViewRootImpl.setView(ViewRootImpl.java:700)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:345)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:224)
        at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:149)
        at android.view.Window$LocalWindowManager.addView(Window.java:554)
        at android.app.Dialog.show(Dialog.java:277)
        at android.support.v7.app.AlertDialog$Builder.show(AlertDialog.java:902)
        at com.mycompany.mooz.MainActivity`enter code here`$MyHandler.handleMessage(MainActivity.java:55)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4921)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
        at dalvik.system.NativeStart.main(Native Method)