如何使用片段将标题放入 ViewPager?

How can I put titles in ViewPager using fragments?(如何使用片段将标题放入 ViewPager?)

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.Davek804 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. Davek804'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

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