fragment 花屏

[CQU_Mr_wang]

最近在做一个项目，主界面里面放了5个fragment，fragment切换采用了add-hide-show方式，能正常使用，但一旦程序运行后，长时间不操作，导致屏幕自然息屏，过一段时间再进去程序，界面就会出现花屏现象，那几个fragment全部重叠在一起。查了下资料，应该是fragment长时间不用被回收导致的问题，但是没有找到解决方案，下面是程序主界面代码，求各位大牛帮忙！！！谢谢!

package com.example.mrwang.xbjzw;

import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.baidu.mapapi.SDKInitializer;
import com.example.mrwang.xbjzw.Fragment.InformationFragment;
import com.example.mrwang.xbjzw.Fragment.JobFragment;
import com.example.mrwang.xbjzw.Fragment.PageFragment;
import com.example.mrwang.xbjzw.Fragment.PersonFragment;
import com.example.mrwang.xbjzw.Fragment.SearchFragment;

//应用主界面  里面分了5个Fragment
public class MainActivity extends BaseActivity implements View.OnClickListener {
    private RelativeLayout layout_page, layout_information, layout_job,layout_search,layout_person;
    private FrameLayout layout_fragment;
    private TextView tv_page, tv_information, tv_job,tv_search,tv_person;
    private ImageView iv_page, iv_information, iv_job,iv_search,iv_person;
    private FragmentManager fragmentManager;
    private PageFragment pageFragment;
    private InformationFragment informationFragment;
    private JobFragment jobFragment;
    private SearchFragment searchFragment;
    private PersonFragment personFragment;
    private Fragment indexFragment;
    Toolbar toolbar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SDKInitializer.initialize(getApplicationContext());
        setContentView(R.layout.activity_main);
        initView();

        fragmentManager = getFragmentManager();
        setTabSelection(0);
    }
    private void initView() {
        toolbar = (android.support.v7.widget.Toolbar) this.findViewById(R.id.toolbar);
        toolbar.setTitle("主页"); // 标题的文字需在setSupportActionBar之前，不然会无效
        toolbar.setTitleTextColor(Color.WHITE);
        this.setSupportActionBar(toolbar);
        layout_fragment = (FrameLayout) findViewById(R.id.layout_fragment);

        layout_fragment = (FrameLayout) findViewById(R.id.layout_fragment);

        layout_page = (RelativeLayout) findViewById(R.id.layout_page);
        layout_information = (RelativeLayout) findViewById(R.id.layout_information);
        layout_job = (RelativeLayout) findViewById(R.id.layout_job);
        layout_search = (RelativeLayout) findViewById(R.id.layout_search);
        layout_person = (RelativeLayout) findViewById(R.id.layout_person);

        tv_page = (TextView) findViewById(R.id.tv_page);
        tv_information = (TextView) findViewById(R.id.tv_information);
        tv_job = (TextView) findViewById(R.id.tv_job);
        tv_search = (TextView) findViewById(R.id.tv_search);
        tv_person = (TextView) findViewById(R.id.tv_person);

        iv_page = (ImageView) findViewById(R.id.iv_page);
        iv_information = (ImageView) findViewById(R.id.iv_information);
        iv_job = (ImageView) findViewById(R.id.iv_job);
        iv_search = (ImageView) findViewById(R.id.iv_search);
        iv_person = (ImageView) findViewById(R.id.iv_person);

        layout_page.setOnClickListener(this);
        layout_information.setOnClickListener(this);
        layout_job.setOnClickListener(this);
        layout_search.setOnClickListener(this);
        layout_person.setOnClickListener(this);
    }
    private void setTabSelection(int index) {
        clearSelection();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        hideFragments(transaction);
        switch (index){
            case 0:
                this.getSupportActionBar().setTitle("首页");
                iv_page.setBackgroundResource(R.drawable.page_press);
                tv_page.setTextColor(getResources().getColor(R.color.bottom_press));
                if (pageFragment == null) {
                    pageFragment = new PageFragment();
                    transaction.add(R.id.layout_fragment, pageFragment,"PAGE");
                } else {
                    indexFragment = fragmentManager.findFragmentByTag("PAGE");
                    transaction.show(indexFragment);
                }
                break;
            case 1:
                this.getSupportActionBar().setTitle("工程信息");
                iv_information.setBackgroundResource(R.drawable.information_press);
                tv_information.setTextColor(getResources().getColor(R.color.bottom_press));
                if (informationFragment == null) {
                    informationFragment = new InformationFragment();
                    transaction.add(R.id.layout_fragment, informationFragment,"INFORMATION");
                } else {
                    
                    indexFragment = fragmentManager.findFragmentByTag("INFORMATION");
                    transaction.show(indexFragment);
                }
                break;
            case 2:
                this.getSupportActionBar().setTitle("求职招聘");
                iv_job.setBackgroundResource(R.drawable.job_press);
                tv_job.setTextColor(getResources().getColor(R.color.bottom_press));
                if (jobFragment == null) {
                    jobFragment = new JobFragment();
                    transaction.add(R.id.layout_fragment, jobFragment,"JOB");
                } else {
                    indexFragment = fragmentManager.findFragmentByTag("JOB");
                    transaction.show(indexFragment);
                }
                break;
            case 3:
                this.getSupportActionBar().setTitle("搜索查询");
                iv_search.setBackgroundResource(R.drawable.search_press);
                tv_search.setTextColor(getResources().getColor(R.color.bottom_press));
                if (searchFragment == null) {
                    searchFragment = new SearchFragment();
                    transaction.add(R.id.layout_fragment, searchFragment,"SEARCH");
                } else {
                    indexFragment = fragmentManager.findFragmentByTag("SEARCH");
                    transaction.show(indexFragment);
                }
                break;
            case 4:
                this.getSupportActionBar().setTitle("个人中心");
                iv_person.setBackgroundResource(R.drawable.person_press);
                tv_person.setTextColor(getResources().getColor(R.color.bottom_press));
                if (personFragment == null) {
                    personFragment = new PersonFragment();
                    transaction.add(R.id.layout_fragment, personFragment,"PERSON");
                } else {
                    transaction.remove(personFragment);
                    personFragment = new PersonFragment();
                    transaction.add(R.id.layout_fragment, personFragment);
                    //transaction.show(personFragment);
                }
                break;
            default:
                break;
        }
        transaction.commit();
    }

    private void clearSelection() {
        iv_page.setBackgroundResource(R.drawable.page);
        tv_page.setTextColor(getResources().getColor(R.color.bottom_font_color));
        iv_information.setBackgroundResource(R.drawable.information);
        tv_information.setTextColor(getResources().getColor(R.color.bottom_font_color));
        iv_job.setBackgroundResource(R.drawable.job);
        tv_job.setTextColor(getResources().getColor(R.color.bottom_font_color));
        iv_search.setBackgroundResource(R.drawable.search);
        tv_search.setTextColor(getResources().getColor(R.color.bottom_font_color));
        iv_person.setBackgroundResource(R.drawable.person);
        tv_person.setTextColor(getResources().getColor(R.color.bottom_font_color));
    }

    private void hideFragments(FragmentTransaction transaction) {
        if (pageFragment != null) {
            transaction.hide(pageFragment);
        }
        if (informationFragment != null) {
            transaction.hide(informationFragment);
        }
        if (jobFragment != null) {
            transaction.hide(jobFragment);
        }
        if (searchFragment != null) {
            transaction.hide(searchFragment);
        }
        if (personFragment != null) {
            transaction.hide(personFragment);
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.layout_page:
                setTabSelection(0);
                break;
            case R.id.layout_information:
                setTabSelection(1);
                break;
            case R.id.layout_job:
                setTabSelection(2);
                break;
            case R.id.layout_search:
                setTabSelection(3);
                break;
            case R.id.layout_person:
                setTabSelection(4);
                break;
        }
    }

}