对Fragment的封装和fragment的显示隐藏回退栈管理

废话不多说，直接上代码

package test.bwie.jiyun.com.ins7566.ipandatv.widget.manger;import android.os.Bundle;import android.support.v4.app.FragmentManager;import android.support.v4.app.FragmentTransaction;import test.bwie.jiyun.com.ins7566.ipandatv.App;import test.bwie.jiyun.com.ins7566.ipandatv.base.BaseFragment;import static test.bwie.jiyun.com.ins7566.ipandatv.App.lastFragment;/** * Created by suyun on 2017/7/28. */public class FragmentBuilder {    private FragmentManager fragmentManager;    private BaseFragment baseFragment;    private FragmentTransaction fragmentTransaction;    private String simpleName;    private FragmentBuilder() {        init();    }    private static FragmentBuilder fragmentBuilder;    public static synchronized FragmentBuilder getInstance() {        if (fragmentBuilder == null) {            fragmentBuilder = new FragmentBuilder();        }        return fragmentBuilder;    }    private void init() {        //初始化并得到fragmentManger管理者对象        fragmentManager = App.activity.getSupportFragmentManager();    }    public FragmentBuilder start(Class<? extends BaseFragment> baseclass, int ViewID) {        //开始事务        fragmentTransaction = fragmentManager.beginTransaction();        //要跳转fragment的类        simpleName = baseclass.getSimpleName();        //用tag标记        baseFragment = (BaseFragment) fragmentManager.findFragmentByTag(simpleName);        if (baseFragment == null) {            try {                baseFragment = baseclass.newInstance();            } catch (InstantiationException e) {                e.printStackTrace();            } catch (IllegalAccessException e) {                e.printStackTrace();            }            //添加到事务            fragmentTransaction.add(ViewID, baseFragment, simpleName);        }        if (lastFragment != null) {            fragmentTransaction.hide(lastFragment);        }        //展示当前页面        fragmentTransaction.show(baseFragment);        //添加到回退栈        fragmentTransaction.addToBackStack(simpleName);        return this;    }    //传参    public FragmentBuilder setParms(Bundle bundle) {        baseFragment.setParams(bundle);        return this;    }    public BaseFragment builder() {        //赋给上一个页面        lastFragment = baseFragment;        //提交事务        fragmentTransaction.commit();        return baseFragment;    }    //清空    public static void clean() {        fragmentBuilder = null;    }}

这个里面完全封装了fragment的跳转，切换，显示隐藏，回退栈管理