这是一个库:https://github.com/astuetz/pagerslidingtabstrip我正试图实现它,但我的应用程序在启动时一直崩溃。 我已经试着理解了样例应用程序的张贴,但不认为我做了一些正确的事情。 下面是我的代码:
Mainactivity.java
import android.graphics.Color; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.LayerDrawable; import android.graphics.drawable.TransitionDrawable; import android.os.Build; import android.os.Bundle; import android.os.Handler; 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; import android.util.TypedValue; import android.view.Menu; import android.view.MenuItem; import android.view.View; import com.astuetz.PagerSlidingTabStrip; public class MainActivity extends FragmentActivity { private final Handler handler = new Handler(); private PagerSlidingTabStrip tabs; private ViewPager pager; private MyPagerAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs); pager = (ViewPager) findViewById(R.id.pager); adapter = new MyPagerAdapter(getSupportFragmentManager()); pager.setAdapter(adapter); tabs.setViewPager(pager); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.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(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } @Override protected void onSaveInstanceState(Bundle outState){ super.onSaveInstanceState(outState); } @Override protected void onRestoreInstanceState(Bundle savedInstanceState){ super.onRestoreInstanceState(savedInstanceState); } private Drawable.Callback drawableCallback = new Drawable.Callback() { @Override public void invalidateDrawable(Drawable who) { getActionBar().setBackgroundDrawable(who); } @Override public void scheduleDrawable(Drawable who, Runnable what, long when) { handler.postAtTime(what, when); } @Override public void unscheduleDrawable(Drawable who, Runnable what) { handler.removeCallbacks(what); } }; public class MyPagerAdapter extends FragmentPagerAdapter{ private final String[] TITLES = {"T1","T2"}; public MyPagerAdapter(FragmentManager fm){ super(fm); } public CharSequence getPageTitle(int position){ return TITLES[position]; } @Override public Fragment getItem(int i) { return null; } @Override public int getCount() { return TITLES.length; } } }
下面是acitivty_main.xml。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="edu.purdue.test.app.MainActivity">
<com.astuetz.PagerSlidingTabStrip
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="48dip" />
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/tabs"
tools:context=".MainActivity" />
</RelativeLayout>
您没有实例化任何希望成为FragmentPagerAdapter,getItem方法中选项卡的片段。 相反,返回的是null,因此没有视图可以填充ViewPager。 我可以看到你已经检查了他的示例项目,也许可以仔细看看你试图添加到视图页的片段。 上面的答案看起来像是一个可靠的实现。
下面是我正在使用的一个例子,
public class Formulario extends FragmentActivity implements ActionBar.TabListener {
private static final FragmentTransaction transaction = null;
public String ambitorec;
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "tab 1", "tab 2", "tab 3" };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_formulario);
ambitorec = getIntent().getStringExtra("ambito");
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
}
您还需要添加适配器,在本例中:
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int index) {
switch (index) {
case 0:
// tab 1 fragment activity
return new Formulario1Fragment();
case 1:
// tab2 fragment activity
return new Formulario2Fragment();
case 2:
// tab 3 fragment activity
return new MultimediaFragment();
}
return null;
}
@Override
public int getCount() {
// get item count - equal to number of tabs
return 3;
}
}
如果你需要更多的帮助,我希望能有所帮助,我会尽力解释的