android - android选项卡中片段的BackStack实现

Question

我的 Android 应用程序需要 Iphone 类型的设计，例如具有选项卡和多个内部屏幕。我完成了应用程序开发，如果我长时间使用该应用程序，现在将面临 OutOfMemoryError。所以我做了谷歌搜索，发现在选项卡中设置活动会消耗更多内存，我在 FragmentTransactions 中使用 replace() 来更改片段。因此，当单击后退键 Fragments 视图被重新创建，这在我的应用程序中非常昂贵，也消耗大量内存。所以我想通过将视图直接设置为选项卡并为片段导航实现自己的后台堆栈来更改我的应用程序架构。我已经实现了下面的代码，它工作正常，但是在整个应用程序过程中使用显示/隐藏是好还是不好？有人可以建议我在下面的代码中实现 backstack 或纠正我的示例。

package com.fragment;

import java.util.ArrayList;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;

public class MainActivity extends FragmentActivity implements OnTabChangedListener {
    ArrayList<Fragment> alTab1 = new ArrayList<Fragment>();
    ArrayList<Fragment> alTab2 = new ArrayList<Fragment>();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    TabHost tabHost = findViewById(android.R.id.tabhost);
    tabHost.setup();
        // Tab for Photos
        TabSpec photospec = tabHost.newTabSpec("Photos");
        // setting Title and Icon for the Tab
        photospec.setIndicator("Photos", getResources().getDrawable(R.drawable.icon_photos_tab));
        photospec.setContent(R.id.tab1content);
        // Tab for Videos
        TabSpec videospec = tabHost.newTabSpec("Videos");
        // setting Title and Icon for the Tab
        videospec.setIndicator("Videos", getResources().getDrawable(R.drawable.icon_videos_tab));
        videospec.setContent(R.id.tab2content);
    tabHost.addTab(photospec);
tabHost.addTab(videospec);
tabHost.setOnTabChangedListener(this);
        FragmentManager fm = getSupportFragmentManager();
        if (fm != null) {
            FragmentTransaction ft = fm.beginTransaction();
            Tab1Fragment1 t1f1 = new Tab1Fragment1();
            ft.add(R.id.tab1content, t1f1, "t1f1");
            addToBackStack(t1f1);
            ft.commit();
        }
    }

    public void onTabChanged(String tabId) {
        if (tabHost.getCurrentTab()==0) {
        }
        if (tabHost.getCurrentTab()==1) {
            if (alTab2.size() == 0) {
                FragmentManager fm = getSupportFragmentManager();
                if (fm != null) {
                    FragmentTransaction ft = fm.beginTransaction();
                    Tab2Fragment1 t2f1 = new Tab2Fragment1();
                    ft.add(R.id.tab2content, t2f1, "t2f1");
                    addToBackStack(t2f1);
                    ft.commit();
                }
            }
        }
    }

    public void addToBackStack(Fragment f) {
        if (tabHost.getCurrentTab()==0) {
            if (alTab1.size() > 0) {
                FragmentTransaction ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.hide(alTab1.get(alTab1.size() - 1));
                ft.commit();
            }
            alTab1.add(f);
        }
        if (tabHost.getCurrentTab()==1) {
            if (alTab2.size() > 0) {
                FragmentTransaction ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.hide(alTab2.get(alTab2.size() - 1));
                ft.commit();
            }
            alTab2.add(f);
        }
    }

    @Override
    public void onBackPressed() {
        if (tabHost.getCurrentTab()==0) {
            if (alTab1.size() > 1) {
                FragmentTransaction ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.remove(alTab1.get(alTab1.size() - 1));
                alTab1.remove(alTab1.size() - 1);
                ft.show(alTab1.get(alTab1.size() - 1));
                ft.commit();
                return;
            }
        }
        if (tabHost.getCurrentTab()==1) {
            if (alTab2.size() > 1) {
                FragmentTransaction ft = getSupportFragmentManager()
                        .beginTransaction();
                ft.remove(alTab2.get(alTab2.size() - 1));
                alTab2.remove(alTab2.size() - 1);
                ft.show(alTab2.get(alTab2.size() - 1));
                ft.commit();
                return;
            }
        }
        super.onBackPressed();
    }

}