FLAG_NEEDS_MENU_KEY cannot be resolved or is not a field 报错，程序无法运行

把getWindow().setFlags(WindowManager.LayoutParams.FLAG_NEEDS_MENU_KEY,
                WindowManager.LayoutParams.FLAG_NEEDS_MENU_KEY);这句话 换成

 try {  
            getWindow().addFlags(WindowManager.LayoutParams.class.getField("FLAG_NEEDS_MENU_KEY").getInt(null));  
        }catch (NoSuchFieldException e) {  
            // Ignore since this field won't exist in most versions of Android  
        }catch (IllegalAccessException e) {  
            Log.w("feelyou.info", "Could not access FLAG_NEEDS_MENU_KEY in addLegacyOverflowButton()", e);  
        }  
就ok了 ，亲测。