Activity中fragment管理(回退)

需求场景:

1.一个注册功能包含一个activity和两个fragment(输入手机号,输入登录密码)2.InputRegisterPhoneFragment-点击下一步>InputLoginPasswordFragment 点击back键->InputRegisterPhoneFragment点击back键->退出注册界面

涉及的类

activity:RegisterActivityfragment:InputRegisterPhoneFragment、InputLoginPasswordFragment

显示fragment

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();ft.replace(R.id.mContainer, InputRegisterPhoneFragment());//这一句很重要目的是添加到Fragment返回栈ft.addToBackStack(null);ft.commit();

点击返回键回调

@Overridepublic void onBackPressed() {    if (getSupportFragmentManager().getBackStackEntryCount() == 1) {        finish();    } else {        super.onBackPressed();    }}