关于彻底解决PopupWindow View not attached to window manager 的方法

最近做项目遇到的问题，出现这类问题基本上都是activity还没启动就show popupwindow 或 activity已经finish还dismiss，这样就会 造成这样的问题

android.view.WindowManagerGlobal.findViewLocked(WindowManagerGlobal.java:406)
android.view.WindowManagerGlobal.updateViewLayout(WindowManagerGlobal.java:295)
android.view.WindowManagerImpl.updateViewLayout(WindowManagerImpl.java:74)
android.widget.PopupWindow.update(PopupWindow.java:1425)
android.widget.PopupWindow$1.onScrollChanged(PopupWindow.java:139)
android.view.ViewTreeObserver.dispatchOnScrollChanged(ViewTreeObserver.java:884)

出现这类问题的预防方法有

if(this != null && !this.isFinishing())
    stepWindow.showAsDropDown(bottomLeftBtn, stepWindowPoint.x, stepWindowPoint.y);

show之前判断activity是否finished

还有在每个popupwindow调用时增加

@Override
protected void onDestroy() {
    if(this != null && !this.isFinishing()) {
        mSharePopupWindow.dismiss();
        mSharePopupWindow = null;
    }

}

当初曾经想要在onPause里

    if(this != null && !this.isFinishing()) {
        mSharePopupWindow.dismiss();

}

但是发现适得其反，出现了问题，