2016-01-04 24 views
0

我有一个小问题,我只有3个片段,我添加到其中一个photoshop背景(1080 x 1920)的事情是,当它加载到手机的标签之间切换滞后很多,但如果我只是渲染图像到720 x 1280它工作正常,没有滞后出现,我实施mViewPager.setOffscreenPageLimit(0);,但它似乎dosnt工作,我不知道是什么造成的问题,我会在这里让我的主代码,在先进的感谢当切换片段时滑动制表符滞后

import android.support.design.widget.TabLayout; 
import android.support.design.widget.FloatingActionButton; 
import android.support.design.widget.Snackbar; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 

import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ViewGroup; 

import android.widget.ExpandableListView; 
import android.widget.TextView; 

public class MainActivity extends AppCompatActivity { 

    /** 
    * The {@link android.support.v4.view.PagerAdapter} that will provide 
    * fragments for each of the sections. We use a 
    * {@link FragmentPagerAdapter} derivative, which will keep every 
    * loaded fragment in memory. If this becomes too memory intensive, it 
    * may be best to switch to a 
    * {@link android.support.v4.app.FragmentStatePagerAdapter}. 
    */ 
    private SectionsPagerAdapter mSectionsPagerAdapter; 

    /** 
    * The {@link ViewPager} that will host the section contents. 
    */ 
    private ViewPager mViewPager; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 
     // Create the adapter that will return a fragment for each of the three 
     // primary sections of the activity. 
     mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); 

     // Set up the ViewPager with the sections adapter. 
     mViewPager = (ViewPager) findViewById(R.id.container); 
     mViewPager.setOffscreenPageLimit(0); 
     mViewPager.setAdapter(mSectionsPagerAdapter); 

     TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs); 
     tabLayout.setupWithViewPager(mViewPager); 

     FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
     fab.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
         .setAction("Action", null).show(); 
      } 
     }); 

    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.menu_main, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 




    /** 
    * A {@link FragmentPagerAdapter} that returns a fragment corresponding to 
    * one of the sections/tabs/pages. 
    */ 


    //-----------------------FRAGMENTS----------------------- 

    public class SectionsPagerAdapter extends FragmentPagerAdapter { 

     public SectionsPagerAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     public Fragment getItem(int position) { 
      // getItem is called to instantiate the fragment for the given page. 
      // Return a PlaceholderFragment (defined as a static inner class below). 


      switch (position) { 
       case 0: 
        Fragment fragment = new DummySectionFragment3(); 
        Bundle args = new Bundle(); 
        args.putInt(DummySectionFragment3.ARG_SECTION_NUMBER, position + 1); 
        fragment.setArguments(args); 
        return fragment; 

       case 1: 
        Fragment fragment2 = new DummySectionFragment2(); 
        Bundle args2 = new Bundle(); 
        args2.putInt(DummySectionFragment2.ARG_SECTION_NUMBER, position + 2); 
        fragment2.setArguments(args2); 
        return fragment2; 

       case 2: 

        Fragment fragment3 = new DummySectionFragment(); 
        Bundle args3 = new Bundle(); 
        args3.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 3); 
        fragment3.setArguments(args3); 
        return fragment3; 


       default: 
        return null; 
      } 
     } 
     //-----------------------FRAGMENTS----------------------- 



     @Override 
     public int getCount() { 
      // Show 3 total pages. 
      return 3; 
     } 



     @Override 
     public CharSequence getPageTitle(int position) { 
      switch (position) { 
       case 0: 
        return "Bares"; 
       case 1: 
        return "No se"; 
       case 2: 
        return "Eventos"; 
      } 
      return null; 
     } 
    } 





    /** 
    * A placeholder fragment containing a simple view. 
    */ 
    public static class PlaceholderFragment extends Fragment { 
     /** 
     * The fragment argument representing the section number for this 
     * fragment. 
     */ 
     private static final String ARG_SECTION_NUMBER = "section_number"; 

     /** 
     * Returns a new instance of this fragment for the given section 
     * number. 
     */ 
     public static PlaceholderFragment newInstance(int sectionNumber) { 
      PlaceholderFragment fragment = new PlaceholderFragment(); 
      Bundle args = new Bundle(); 
      args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
      fragment.setArguments(args); 
      return fragment; 
     } 

     public PlaceholderFragment() { 
     } 




     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_main, container, false); 
      TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label); 
      dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER))); 
      return rootView; 
     } 
    } 
    } 

回答

0

你不说你如何加载背景。

但是,如果您只是简单地设置了片段布局,那么当您膨胀XML时图像就会被加载。这发生在UI线程中。图像越大,需要的时间越长。

我会推荐使用像Picasso这样的异步库加载图像。

0

我有同样的问题。首先,我认为图像的数据大小很大,但事实并非如此。我在Photoshop中更改了图像的尺寸并减小了宽度。现在它工作正常。

1

我实现了mViewPager.setOffscreenPageLimit(0);但现在看来,这 dosnt工作

首先,

你为什么要设置页面限制0如果你希望更顺畅的刷卡?

做得一样(如果你有3标签刚刚成立limiit到1,如果5项,将其设置为2会工作)

mViewPager.setOffscreenPageLimit(2); 

这意味着你是迫使caching您2左2右从当前选项卡选项卡。

因此,他们不会被反复加载,而是会被缓存。

注意话虽如此,你应该记住,它会消耗更多的内存,并避免不必要的内存消耗。

希望它帮助某人。