安卓 M ClassCastException : FrameLayout$LayoutParams cannot be cast to WindowManager$LayoutParams

Question

这段代码似乎适用于 android api 16 - 22，但不适用于 api 23。我只是想显示一个带有选项的弹出窗口，并使弹出窗口下方的背景变暗:

                WindowPopUp windowPopUp =
                        new WindowPopUp(mContext, mPlaces.get(position), position, fromSearch);
                windowPopUp.showAtLocation(v, Gravity.CENTER, 0, 0);
                View parent = (View) windowPopUp.getContentView().getParent();
                //dim the window in the background
                WindowManager wm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
                WindowManager.LayoutParams p = (WindowManager.LayoutParams) parent.getLayoutParams();
                p.flags = WindowManager.LayoutParams.FLAG_DIM_BEHIND;
                p.dimAmount = 0.4f;
                wm.updateViewLayout(parent, p);

运行此代码会导致错误:

                03-18 21:55:19.674 8814-8814/? E/AndroidRuntime: FATAL EXCEPTION: main
                                             Process: com.myapp, PID: 8814
                                             java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.view.WindowManager$LayoutParams
                                                 at com.bemyapp.adapter.OuterPlaceAdapter$5.onLongClick(OuterPlaceAdapter.java:400)
                                                 at android.view.View.performLongClick(View.java:5237)
                                                 at android.view.View$CheckForLongPress.run(View.java:21121)
                                                 at android.os.Handler.handleCallback(Handler.java:739)
                                                 at android.os.Handler.dispatchMessage(Handler.java:95)
                                                 at android.os.Looper.loop(Looper.java:148)
                                                 at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

出了什么问题？

据我所知，WindowManager.LayoutParams 扩展了 ViewGroup.LayoutParams，当我调用 parent.getLayoutParams() 时，它返回一个ViewGroup.LayoutParams 所以不应该有 classCastException。

Answer 1

只需再添加一个 .getParent() 即可访问容器。

 if (android.os.Build.VERSION.SDK_INT > 22) {
            container = (View) pwindow.getContentView().getParent().getParent();
        }else{
            container = (View) pwindow.getContentView().getParent();
        }