Android FragmentTabs.java中的TabListener构造函数
在Android API示例中,我在TabListener类中看到了以下构造函数代码:Android FragmentTabs.java中的TabListener构造函数,android,constructor,fragment,android-actionbar,Android,Constructor,Fragment,Android Actionbar,在Android API示例中,我在TabListener类中看到了以下构造函数代码: // Check to see if we already have a fragment for this tab, probably // from a previously saved state. If so, deactivate it, because our // initial state is that a tab isn't shown.
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn't shown.
mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
if (mFragment != null && !mFragment.isDetached()) {
FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
ft.detach(mFragment);
ft.commit();
}
有人能告诉我在什么情况下if子句可以返回true吗?我想不出这种情况。谢谢。当您将手机从纵向转向横向或向后时 当前活动选项卡将不会分离
我只是通过在该子句中添加断点来测试它。非常感谢您的帮助!另一方面,我认为当我打开设备时,完整的活动及其片段会被破坏,然后重建。配置更改后,碎片怎么可能仍然存在?似乎系统会自动销毁,但在重新创建活动时会重新创建所有碎片。但我仍然不确定是否需要额外的代码,是否正确。。。