问题描述

我正在使用 ViewPager 允许用户在片段之间滑动.

I am using ViewPager to allow user to swipe between fragments.

如何在屏幕上添加每个片段的标题?

How can I add a the title of each fragment to the screen?

package com.multi.andres;

import java.util.List;
import java.util.Vector;

import com.viewpagerindicator.TitlePageIndicator;
import com.viewpagerindicator.TitleProvider;

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 ViewPagerFragment extends FragmentActivity{

    private PagerAdapter mPagerAdapter; //contiene el pager adapter
    private static String[] titulosPaginas = { "APP 1", "APP 2" };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.lcmeter); //layout que contiene el ViewPager

        initialisePaging(); //inicializo las paginas
    }

    private void initialisePaging() {

        List<Fragment> fragments = new Vector<Fragment>();
        fragments.add(Fragment.instantiate(this, FragmentPrueba1.class.getName()));
        fragments.add(Fragment.instantiate(this, FragmentPrueba2.class.getName()));
        this.mPagerAdapter  = new PagerAdapter(super.getSupportFragmentManager(), fragments);

        ViewPager pager = (ViewPager)super.findViewById(R.id.pager);
        pager.setAdapter(this.mPagerAdapter);

        //Agrega los titulos
        TitlePageIndicator titleIndicator = (TitlePageIndicator) findViewById(R.id.titulos);    //layout XML
        titleIndicator.setViewPager(pager);
    }

    /** *************************************************************************************************
    /** Clase:   public class PagerAdapter extends FragmentPagerAdapter implements TitleProvider
    /** Notas:   extends FragmentPagerAdapter permite el uso de las paginas de ViewPager pero con Fragments
    /**          implements TitleProvider permite el uso de los titulos en las paginas
    /** Funcion: crea paginas por las cuales deslizarse horizontalmente las cuales son usadas
    ****************************************************************************************************/
    public class PagerAdapter extends FragmentPagerAdapter implements TitleProvider {

        private List<Fragment> fragments;

        public String getTitle(int position) {
            // TODO Auto-generated method stub
            return titulosPaginas[position];    // titulo de la pagina
        }

        public PagerAdapter(FragmentManager fm, List<Fragment> fragments) {
            super(fm);
            this.fragments = fragments;
        }

        @Override
        public int getCount() {
            return this.fragments.size();
        }

        @Override
        public Fragment getItem(int position) {
            return this.fragments.get(position);
        }

    }

}

但它没有显示 ViewPager 的标题，我不知道为什么.我以前使用 ViewPager 与标题，但没有与片段一起使用，我现在无法使标题正常工作.

But it doesn't show the titles of ViewPager and I don't know why. I used ViewPager with titles before but not with fragments and I cannot get titles working now.

推荐答案

您也可以使用 Jake Wharton 的 ViewPagerIndicator 库来得到想要的效果.Dave**04 的答案也有效，但它需要您引用整个 ActionBarSherlock 库，如果您只需要一个支持自定义/样式标题的 ViewPager，那么这不是可取的.

You can also use Jake Wharton's ViewPagerIndicator library to get the desired effect. Dave**04's answer works too, but it requires you to reference the entire ActionBarSherlock library, which isn't as preferable if you only need a ViewPager that supports custom/styled titles.

设置它以使其正常工作只需编写一点点 XML，在 Activity 中初始化 ViewPager，然后实现 FragmentAdapter(其中 extends FragmentPagerAdapter 实现 TitleProvider)指定哪些页面保存哪些 Fragment.

Setting it up to work correctly is simply a matter of writing a tiny bit of XML, initializing your ViewPager in your Activity, and implementing a FragmentAdapter (which extends FragmentPagerAdapter implements TitleProvider) to specify which pages hold which Fragments.

1. XML 布局

1. XML layout

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.viewpagerindicator.TabPageIndicator
        android:id="@+id/titles"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

</LinearLayout>

//Set the pager with an adapter
ViewPager pager = (ViewPager)findViewById(R.id.pager);
pager.setAdapter(new CustomAdapter(getSupportFragmentManager()));

//Bind the title indicator to the adapter
TitlePageIndicator titleIndicator = (TitlePageIndicator) findViewById(R.id.titles);
titleIndicator.setViewPager(pager);

public static class CustomFragmentAdapter extends FragmentPagerAdapter 
        implements TitleProvider {

        public static final int POSITION_PAGE_1 = 0;
        public static final int POSITION_PAGE_2 = 1;
        public static final int POSITION_PAGE_3 = 2;

        private static final String[] TITLES = new String[] { 
            "Title 1", 
            "Title 2", 
            "Title 3" 
        };

        public static final int NUM_TITLES = TITLES.length;

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

        @Override
        public Fragment getItem(int position) {     
            switch (position) {
            case POSITION_TITLE_1:              
                return PageOneFragment.newInstance();
            case POSITION_TITLE_2: 
                return PageTwoFragment.newInstance();
            case POSITION_TITLE_3:
                return PageThreeFragment.newInstance();         
            }
            return null;
        }

        @Override
        public int getCount() {
            return NUM_TITLES;
        }

        @Override
        public String getTitle(int position) {
            return TITLES[position % NUM_TITLES].toUpperCase();
        }
    }

<小时>

ViewPagerIndicator 库支持标题功能:

The ViewPagerIndicator library supports the titling features:

1. TitlePageIndicator

TabPageIndicator

CirclePageIndicator