尽管使用了 WeakReference，AlertDialog 仍会泄漏

Question

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。

详情：

我有一个 Activity，线程和处理程序带有对 activity 的 WeakReference。在我开始我的线程之前，我在我的 activity class 中创建了 ProgressDialog dialog。线程任务有一个对 MyHandler 对象的引用。当用户在我的 activity 中关闭 dialog 时，onCancelListener 调用线程的 interrupt()。我的线程安全地完成任务并将消息 DOWNLOAD_STATE.CANCELLED 发送到主线程 activity。然后我用 MyHandler

中的代码创建 AlertDialog

问题：

问题是当用户在关闭 alert（取消线程）后且在创建新的 AlertDialog 之前（在 MyHandler class 内）立即按下后退按钮时。花了大约一秒钟。当用户此时不按回键时，一切正常。

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

正常情况是当用户按下后退按钮时，activity 被销毁（activity onBackKeyPressed 的效果），但为什么 handleMessage 没有停止并创建 AlertDialog？

我的经纪人class:

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：

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)

Answer 1

Activity com.mycompany.mooz.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@42723848 that was originally added here

通常在 Activity 暂停且对话框仍在屏幕上时发生。如果引用不为空且对话框 isShowing

，请保留对您的对话框的引用并在 onPause 中调用关闭

  if (mDialog != null && mDialog.isShowing()) {
        mDialog.dismiss();
  }

android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@427329e0 is not valid; is your activity running?

当您在 Activity 暂停时尝试显示对话框时，通常会发生这种情况。为了避免检查 isFinishing 标志

  if (activity != null && !activity.isFinishing()) {
      // show dialog
  }

尽管使用了 WeakReference，AlertDialog 仍会泄漏

AlertDialog leaks despite using a WeakReference

android

android-alertdialog

weak-references

详情：

问题：