场景:使用Fragment实现切页。
类结构:
一:Activity
Activity中使用getSupportFragmentManager().beginTransaction()来填充一个Fragment(管理用的FragmentA)
Activity部分代码:
FragmentA fragment = FragmentA.newInstant(null); getSupportFragmentManager().beginTransaction().add(R.id.f_tab_fragment,fragment).commit();
XML:
<FrameLayout android:id="@+id/fl_container" android:layout_width="match_parent" android:layout_above="@+id/f_tab_fragment" android:layout_height="match_parent"/> <FrameLayout android:id="@+id/f_tab_fragment" android:layout_width="match_parent" android:layout_height="52dp" android:layout_alignParentBottom="true"/>
二:FragmentA
加载一个主FragmentA,作为管理其它子叶片FragmentX。
现在比如有两个子叶片FragmentB、FragmentC.
FragmentA 使用FragmentManager和FragmentTransaction管理FragmentB、FragmentC的切换
FragmentA代码:
public class FragmentA extends BaseFragment { private static final String TAB_HOME = com.timediffproject.module.home.MyMainFragment.class.getName(); private static final String TAB_TEST = com.timediffproject.module.home.TestFragment.class.getName(); private BaseFragment mLastShowFragment; private static TabFragment fragment; public static TabFragment newInstant(Bundle bundle){ if (fragment == null){ fragment = new TabFragment(); fragment.setArguments(bundle); } return fragment; } @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); initTabInfo(); } private void initTabInfo(){ FragmentManager fm = getFragmentManager(); if (fm == null){ return; } FragmentTransaction ft = fm.beginTransaction(); BaseFragment home = (BaseFragment) fm.findFragmentByTag(TAB_HOME); if (home != null){ ft.hide(home); } BaseFragment test = (BaseFragment) fm.findFragmentByTag(TAB_TEST); if (test != null){ ft.hide(test); } ft.commit(); } @Nullable @Override public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) { return inflater.inflate(R.layout.fragment_tab,container,false); } @Override public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); view.findViewById(R.id.btn_change_home).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { switchTo(TAB_HOME,null); } }); view.findViewById(R.id.btn_change_test).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { switchTo(TAB_TEST,null); } }); switchTo(TAB_HOME,null); } //切换Fragment的方式(FragmentB、FragmentC) //tab为Fragment的类名(如:FragmentB.class.getName()) //R.id.fl_container是在Activity的布局里,不是在FragmentA的布局里 private void switchTo(String tab, Bundle bundle){ //初始化管理Fragment的类 FragmentManager fm = getFragmentManager(); if (fm == null){ return; } FragmentTransaction ft = fm.beginTransaction(); //从FragmentManager里寻找类名为tab的Fragment BaseFragment fragment = (BaseFragment)fm.findFragmentByTag(tab); if (fragment == null){ fragment = (BaseFragment) Fragment.instantiate(getActivity(),tab); fragment.setArguments(bundle); ft.add(R.id.fl_container,fragment,tab); }else{ ft.show(fragment); } //隐藏现在正显示的Fragment if (mLastShowFragment != null) { ft.hide(mLastShowFragment); } //记录最后点击的Fragment mLastShowFragment = fragment; ft.commitAllowingStateLoss(); } }
XML:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="52dp"> <Button android:id="@+id/btn_change_home" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="切换home" /> <Button android:id="@+id/btn_change_test" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="切换test" /> </LinearLayout>
三:FragmentX(FragmentB、FragmentC)
子页的逻辑根据具体业务自己定义,实现与一般Fragmeng一样
例如:
public class TestFragment extends BaseFragment { @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {return inflater.inflate(R.layout.fragment_test,container,false); } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); } }
到这里,就可以简单的实现-用底部Tab切换Fragment实现切页的功能
附图:
PS:实现过程中出现的错误
正确方式: 有关的fragment的初始化布局应该加上false,与父类布局建立关系。
原因:不加的话这个inflater出来的view系统会绑定一个未知父类,这时候当你把这个fragment又作为子页绑定给Activity或者另一个fragment时,就会出现以上错误。
@Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { //这里正确的写法是: //return inflater.inflate(R.layout.fragment_test,container,false); return inflater.inflate(R.layout.fragment_test,container); }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。