我有一点问题，我只有3个片段而且我在其中一个片段中添加了photoshop背景（1080 x 1920），当它加载到手机时，标签之间的切换滞后很多，但是如果我只是将图像渲染到720 x 1280它工作正常并且没有出现延迟，我实现了mViewPager.setOffscreenPageLimit(0);但似乎它没有用，我不知道是什么导致了这个问题，我会在这里让我的主要代码，谢谢你先进
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;
}
}
}
答案 0 :(得分：2)
我实现了mViewPager.setOffscreenPageLimit（0）;但它似乎 dosnt工作
首先，
如果您希望更顺畅的滑动，为什么将页面限制设置为0 ？
执行此操作（如果您有3个标签只设置为1的限制，如果有5个标签，则将其设置为2将起作用）
mViewPager.setOffscreenPageLimit(2);
这意味着您从当前标签中强制显示左侧和右侧两个标签的caching。
因此他们不会一次又一次地加载它们而是会被缓存。
注意尽管如此，你应该记住它会占用更多内存并避免不必要的内存消耗。
希望它有所帮助。答案 1 :(得分：0)
答案 2 :(得分：0)
我遇到了同样的问题。首先，我认为图像的数据大小很大，但事实并非如此。我在Photoshop中更改了图像的测量并减小了宽度。现在它工作正常。