如何按照某些顺序加载片段，以便我可以减少应用启动时间

Question

我有一个选项卡布局，每个选项卡都有单独的片段，首先片段显示了从服务器获取的RSS新闻feed，此新闻片段需要大量时间来加载，因此我重新安排了最终新闻片段的方式。但是，启动该应用程序仍然需要同样的时间。我需要一些帮助来加载缩短的发射时间，首先显示较少负载的碎片选项卡。

这是我的标签布局活动，这是我的代码

 public class NewActivity extends FragmentActivity {
        String user_retr_password=null;
        String newpassword;
        String dobstr;
        String currentdate;
        Boolean doubleBackToExitPressedOnce = false;
        String id,regid;
        String mobileno;
        Session se;
        UserInfo UInfo;
        private Toolbar toolbar;
        private TabLayout tabLayout;
        private ViewPager viewPager;
        private int[] tabIcons = {
                R.drawable.news123,
                R.drawable.notification,
                R.drawable.club3,
                R.drawable.myspaces
                R.drawable.Home
        };
        ImageButton userImage_ImageButton;
        Bitmap UserImage = null;
        Context context;
        Point p;
        public static FragmentManager fragmentManager;
        private ProgressBar mProgressBar;
        RelativeLayout LoadingPanel;
        int TabSelected = 0;
        public static LocationManager locationManager;
        public static LocationListener locationListener;
        static List<AdvertizementTableModel.AdvInfo> Adv_List = new ArrayList<AdvertizementTableModel.AdvInfo>();
        static List<Bitmap> AdvertizementImagesList = new ArrayList<Bitmap>();
        PopupWindow popup;
        WebView Adv_myWebView;
        static PopupWindow popupWebView = null;
        static AnimationDrawable animation = new AnimationDrawable();
        static boolean activeActivity = false;
        private GoogleApiClient client;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.newactivity);
            context = getApplicationContext();
            fragmentManager = getSupportFragmentManager();
            UInfo = (UserInfo) getIntent().getSerializableExtra("UInfo");

            try {
                Date dob = UInfo.getDateOfBirth();
                SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
                dobstr = df.format(dob);
            }catch(Exception e){}
            Calendar c = Calendar.getInstance();

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            currentdate = sdf.format(c.getTime());
            mobileno=UInfo.getMobile().toString();
            TabSelected = (Integer) getIntent().getIntExtra("TAB", 0);
            userImage_ImageButton = (ImageButton) findViewById(R.id.userImage_ImageButton);
            LoadingPanel = (RelativeLayout) findViewById(R.id.LoadingPanel_NewActivity);
            viewPager = (ViewPager) findViewById(R.id.viewpager);
            Adv_myWebView = (WebView) findViewById(R.id.webview);

            tabLayout = (TabLayout) findViewById(R.id.rsscategory_tabs);
            tabLayout.setVisibility(View.INVISIBLE);
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);

            LoadingPanel.setVisibility(View.VISIBLE);
            mProgressBar.setVisibility(View.VISIBLE);
            registerInBackground();
            userImage_ImageButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    showPopup(aappen.com.buddiesnew.NewActivity.this, p);
                }
            });
           GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
            try {
                checkEnteryinUser();
                checkEnteryinUserprofile();
                getIdRegId(UInfo.getMobile());
            }catch(Exception e){
            }
            retrievepasswordfromphp();
        }

registerinbackground（）方法代码

 new AsyncTask<Void, Void, String>() {
        @Override
        protected String doInBackground(Void... params) {
            String msg = "";
            setUserPicFromSqlite();
            return msg;
        }
        @Override
        protected void onPostExecute(String msg) {
            runOnUiThread(new Runnable() {
                public void run() {

                    setupViewPager(viewPager);
                    setupTabIcons();
                    tabLayout.setupWithViewPager(viewPager);   
                }
            });

            ViewTreeObserver vto = userImage_ImageButton.getViewTreeObserver();
            vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
                public boolean onPreDraw() {
                    userImage_ImageButton.getViewTreeObserver().removeOnPreDrawListener(this);
                    width = userImage_ImageButton.getMeasuredHeight();
                    height = userImage_ImageButton.getMeasuredWidth();

                    Bitmap circleBitmap = getRoundedCroppedBitmap(UserImage, width - 2);
                    userImage_ImageButton.setImageBitmap(circleBitmap);
                    return true;
                }
            });
            LoadingPanel.setVisibility(View.INVISIBLE);
            LoadingPanel.setVisibility(View.INVISIBLE);
            mProgressBar.setVisibility(View.INVISIBLE);
            tabLayout.setVisibility(View.VISIBLE);
            getAdvertizementDetailsInBackgroundFromSqlite();

        }
    }.execute(null, null, null);
}

OnPostExcute具有此代码

 private void setupTabIcons() {
        tabLayout.getTabAt(0).setIcon(tabIcons[0]);
        tabLayout.getTabAt(1).setIcon(tabIcons[1]);
        tabLayout.getTabAt(2).setIcon(tabIcons[2]);
        tabLayout.getTabAt(3).setIcon(tabIcons[3]);
        tabLayout.getTabAt(4).setIcon(tabIcons[4]);
    }
    private void setupViewPager(final ViewPager viewPager) {
        final NewActivity.ViewPagerAdapter adapter = new NewActivity.ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFragment(new TabFragment7(), "News");
        adapter.addFragment(new TabFragment2(), "Message");
        adapter.addFragment(new TabFragment4(), "Club");
        adapter.addFragment(new TabFragment0(), "Home");
        adapter.addFragment(new TabFragment5(), "My Space");
        viewPager.setAdapter(adapter);
        viewPager.setCurrentItem(TabSelected);
        viewPager.setOffscreenPageLimit(4);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }
            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
            }
            @Override
            public void onTabReselected(TabLayout.Tab tab) {
            }
        });
    }

ViewPager adapter

class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();
        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }
        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }
        @Override
        public int getCount() {
            return mFragmentList.size();
        }
        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }
        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
    }

选项卡布局0 [获取新闻feed]

 public class TabFragment0 extends Fragment {
        UserInfo UInfo;
        Context context;
        ImageButton EditImageButton;
        Bitmap ImageBitmap = null, LogoBitmap=null;
        int width;
        int height;
        TableLayout tl;
        TableRow tr;
        ImageView RssurlImageView;
        Bitmap RssImageBitmap;
        ImageView RssSourceImage;
        Activity context1;
        WebView mWebview;
        ImageButton closeWebView_Button, RssCategoryEdit_Button,share_ImageButton;
        List<RSSMasterInfo> RSSMasterList = new ArrayList<RSSMasterInfo>();
        String Names,Urls,Imagelinks;
        String[] newsnames, newsurls, newslogo;
        List<String> NewsNameList = new ArrayList<String>();
        List<String> NewsUrlsList = new ArrayList<String>();
        List<String> NewsLogoList = new ArrayList<String>();
        List<RSSMasterInfo.RssfeedSubCategoryLink> RssLinkForOnTouch = new ArrayList<RSSMasterInfo.RssfeedSubCategoryLink>();
        RSSMasterInfo.RssfeedSubCategoryLink rssOnTouchInfo = new RSSMasterInfo.RssfeedSubCategoryLink();
        ScrollView scrollview;
        ImageButton reloadImageButton;
        int finalImagecount = 0;
        static boolean activeActivity = false;
        static Boolean UpdateImagesFlag = false;
        SwipeRefreshLayout swipeRss;
        boolean isItPrinted = false;
        String Link=null;

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.tab_fragment_0, null, false);
            UInfo = (UserInfo) getActivity().getIntent().getSerializableExtra("UInfo");
            EditImageButton = (ImageButton) view.findViewById(R.id.Rss_EditImageButton);
            RelativeLayout rl = (RelativeLayout) view.findViewById(R.id.rssfeed_relativelayout);
            tl = (TableLayout) view.findViewById(R.id.rsstablelayout);
            reloadImageButton = (ImageButton) view.findViewById(R.id.ReloadImages_ImageButton);
            mWebview = (WebView) view.findViewById(R.id.rssFeed_WebView);
            closeWebView_Button = (ImageButton) view.findViewById(R.id.closeWebView_Button);
            RssCategoryEdit_Button = (ImageButton) view.findViewById(R.id.Rss_EditImageButton);
            scrollview = (ScrollView) view.findViewById(R.id.mainscrollView);
            share_ImageButton=(ImageButton)view.findViewById(R.id.share_ImageButton);
            // swipeRss = (SwipeRefreshLayout) view.findViewById(R.id.swipreRssRefresh);
            mWebview.setVisibility(View.INVISIBLE);
            closeWebView_Button.setVisibility(View.INVISIBLE);
            share_ImageButton.setVisibility(View.INVISIBLE);
            context = getActivity().getApplicationContext();
            context1 = getActivity();


            deleteRssImages();
            RssSourceImage = (ImageView) view.findViewById(R.id.RssSourceImageView);
            finalImagecount = 0; //Returns the number of STATIC IMAGES i.e The Images that are loaded when there is no RSS FEED.

            reloadImageButton.setVisibility(View.VISIBLE);
            reloadImageButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    reloadImageButton.setVisibility(View.VISIBLE);
                    tryGetNewFeed();

                }
            });

            scrollview.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    onTouchEvent(event);
                    return false;
                }
            });

            return view;
        }

        @Override
        public void onStart() {
            super.onStart();
            try {
                //startFeedTab();
                getFinalRSSfeeds();  //this gets Rss news feed.....
                // tryGetNewFeed();
            } catch (Exception e1) {
                e1.printStackTrace();
            }
        activeActivity = true;
        }

Answer 1

好吧，您可以在打开应用程序并使用db或sharedPreferences保存获取的数据后执行请求，并且一旦用户打开选项卡显示存储的数据。这是一个解决方案，我认为我以前做过这样的事情，但是它与图像列表一起使用。

您还可以尝试一个网络库，该网络库可以比本机异步箱更快获取数据，例如：快速Android网络或Android异步HTTP客户端等。

Answer 2

要减少应用程序启动时间，您可以遵循基本方法。

您可以创建一个没有视图的假片段，然后在一定的延迟后用原始片段替换。

在您的 pagerAdapter getItem()中，您可以如下修改：

public Fragment getItem(int position) {
        if (position == TAB_ONE) {
            if (Utility.isEmpty(fragmentOne)) {
                //Here I pass the fragment to be loaded along with the delay, i.e. 50ms
                fragmentOne = FragmentFake.create(new FragmentOne(), 50);
            }
            return fragment;
        } else if (position == TAB_TWO) {
            if (Utility.isEmpty(fragmentTwo)) {
                //FragmentTwo created with a delay of 100ms
                fragmentTwo = FragmentFake.create(new FragmentOne(), 100);
            }
            return fragmentTwo;
        } else if (position == TAB_THREE) {
            if (Utility.isEmpty(fragmentThree)) {
                //FragmentThree created with a delay of 100ms
                fragmentThree = FragmentFake.create(new FragmentThree(), 150);
            }
            return fragmentThree;
        } 
        return null;
    }

和您的 FragmentFake 类将是：

public class FragmentFake extends Fragment {
private View root;
Fragment fragment;
public static Fragment create(Fragment frag, int timeMs) {
    FragmentFake fragmentFake = new FragmentFake();
    Bundle bundle = new Bundle();
    fragmentFake.fragment = frag;
    bundle.putInt("time", timeMs);
    fragmentFake.setArguments(bundle);
    return fragmentFake;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    root = inflater.inflate(R.layout.layout_fake_fragment, container, false);
    Bundle bundle = getArguments();
    replaceFragment(bundle.getInt("time"));
    return root;
}
//Replacing fragments with a delay
private void replaceFragment(int time) {
    root.postDelayed(new Runnable() {
        @Override
        public void run() {
            if(!isAdded()){
                return;
            }
            if (!Utility.isEmpty(fragment)) {
                getChildFragmentManager().beginTransaction().add(R.id.replace_fragment_container, fragment).commit();
            }
        }
    }, time);
}
}

utility.java

public class Utility {
  public static boolean isEmpty(Object object) {
    return object == null;
  }
}

FragmentFake布局只是一个FrameLayout，它将包含替换的片段

fragment_fake_layout.xml

<FrameLayout
    android:id="@+id/replace_fragment_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</FrameLayout>