在加载应用程序打开的所有片段 [英] Load all fragments on app opening

问题描述

我有一个使用片段创建一个页面适配器的应用程序。我使用它来创建它加载不同片段的刷卡标签。每个片段输出的WebView它显示一个特殊格式的网站。现在我的应用程序只加载它是碎片和那些到左边和右边。我想一次和永远不会再加载所有六个选项卡。有没有办法做到这一点？

 进口android.content.res.Configuration;
进口android.os.Bundle;
进口android.support.v4.app.Fragment;
进口android.support.v4.app.FragmentActivity;
进口android.support.v4.app.FragmentManager;
进口android.support.v4.app.FragmentPagerAdapter;
进口android.support.v4.view.ViewPager;公共类MainActivity扩展FragmentActivity {    ViewPager viewPager = NULL;    @覆盖
    保护无效的onCreate（捆绑savedInstanceState）{
            super.onCreate（savedInstanceState）;
            的setContentView（R.layout.activity_main）;
            viewPager =（ViewPager）findViewById（R.id.pager）;
            FragmentManager fragmentManager = getSupportFragmentManager（）;
            viewPager.setAdapter（新MyAdapter（fragmentManager））;
    }    @覆盖
    公共无效onConfigurationChanged（配置NEWCONFIG）{
      super.onConfigurationChanged（NEWCONFIG）;
    }}类MyAdapter扩展FragmentPagerAdapter {
    公共MyAdapter（FragmentManager FM）{
            超（FM）;            // TODO自动生成构造函数存根
    }    @覆盖
    公共片段的getItem（int i）以{
            片段片段= NULL;
            如果（我== 0）=片段介绍新（）;
            如果（我== 1）片段=新球馆（）;
            如果（我== 2）片段=新游戏（）;
            如果（我== 3）=片段新型机器人（）;
            如果（我== 4）片段=新的赛会（）;
            如果（我== 5）片段=新词汇表（）;
            返回片段;
    }    @覆盖
    公众诠释的getCount（）{
            // TODO自动生成方法存根
            返回6;
    }    公共CharSequence的getPageTitle（INT位置）{
            字符串title =新的String（）;
            如果（位置== 0）返回摘要;
            如果（位置== 1）回归竞技场;
            如果（位置== 2）回报比赛;
            如果（位置== 3）回归机器人;
            如果（位置== 4）回归的对抗赛;
            如果（位置== 5）返回词汇表;
            返回null;
    }
}
 

解决方案

通话<一个href=\"http://developer.android.com/reference/android/support/v4/view/ViewPager.html#setOffscreenPageLimit%28int%29\">setOffscreenPageLimit比一半的片段更高一些。
这将迫使viewpager创建和保存所有创建的片段，你在你的适配器有。

  @覆盖
保护无效的onCreate（捆绑savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.activity_main）;
        viewPager =（ViewPager）findViewById（R.id.pager）;
        //用一些高于一半的片段。
        viewPager.setOffscreenPageLimit（4）;
        FragmentManager fragmentManager = getSupportFragmentManager（）;
        viewPager.setAdapter（新MyAdapter（fragmentManager））;
}
 

I have an app that uses fragments to create a page adapter. I use this to create a swipe tab which loads a different fragment. Each fragment loads webview which displays a specially formatted website. Right now my app only loads the fragments it is on and the ones to the left and right of it. I would like to load all six tabs at once and never again. Is there a way to do this?

import android.content.res.Configuration;
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.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity {

    ViewPager viewPager=null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            viewPager = (ViewPager) findViewById(R.id.pager);
            FragmentManager fragmentManager=getSupportFragmentManager();
            viewPager.setAdapter(new MyAdapter(fragmentManager));     
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
      super.onConfigurationChanged(newConfig);
    }

}

class MyAdapter extends FragmentPagerAdapter {


    public MyAdapter(FragmentManager fm) {
            super(fm);

            // TODO Auto-generated constructor stub
    }

    @Override
    public Fragment getItem(int i) {
            Fragment fragment=null;
            if(i==0)fragment=new Introduction();
            if(i==1)fragment=new Arena();
            if(i==2)fragment=new Game();
            if(i==3)fragment=new Robot();
            if(i==4)fragment=new Tournament();
            if(i==5)fragment=new Glossary();
            return fragment;
    }

    @Override
    public int getCount() {
            // TODO Auto-generated method stub
            return 6;
    }

    public CharSequence getPageTitle(int position) {
            String title=new String();
            if(position==0)return "Summary";
            if(position==1)return "The Arena";
            if(position==2)return "The Game";
            if(position==3)return "The Robot";
            if(position==4)return "The Tournament";
            if(position==5)return "Glossary";
            return null;
    }
}

解决方案

call setOffscreenPageLimit with a number higher than half your fragments. This will force the viewpager to create and keep all of the fragments created as you have in your adapter.

@Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        viewPager = (ViewPager) findViewById(R.id.pager);
        // use a number higher than half your fragments.
        viewPager.setOffscreenPageLimit(4);
        FragmentManager fragmentManager=getSupportFragmentManager();
        viewPager.setAdapter(new MyAdapter(fragmentManager));     
}

这篇关于在加载应用程序打开的所有片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！